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You searched for subject:(cooperative spectrum sensing). Showing records 1 – 30 of 38 total matches.
1. Kozal, Ahmed Sultan Bilal. Multi user cooperation spectrum sensing in wireless cognitive radio networks.
Degree: PhD, 2015, Liverpool John Moores University
URL: https://doi.org/10.24377/LJMU.t.00004474  ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.658129
► With the rapid proliferation of new wireless communication devices and services, the demand for the radio spectrum is increasing at a rapid rate, which leads… (more)
▼ With the rapid proliferation of new wireless communication devices and services, the demand for the radio spectrum is increasing at a rapid rate, which leads to making the spectrum more and more crowded. The limited available spectrum and the inefficiency in the spectrum usage have led to the emergence of cognitive radio (CR) and dynamic spectrum access (DSA) technologies, which enable future wireless communication systems to exploit the empty spectrum in an opportunistic manner. To do so, future wireless devices should be aware of their surrounding radio environment in order to adapt their operating parameters according to the real-time conditions of the radio environment. From this viewpoint, spectrum sensing is becoming increasingly important to new and future wireless communication systems, which is designed to monitor the usage of the radio spectrum and reliably identify the unused bands to enable wireless devices to switch from one vacant band to another, thereby achieving flexible, reliable, and efficient spectrum utilisation. This thesis focuses on issues related to local and cooperative spectrum sensing for CR networks, which need to be resolved. These include the problems of noise uncertainty and detection in low signal to noise ratio (SNR) environments in individual spectrum sensing. In addition to issues of energy consumption, sensing delay and reporting error in cooperative spectrum sensing. In this thesis, we investigate how to improve spectrum sensing algorithms to increase their detection performance and achieving energy efficiency. To this end, first, we propose a new spectrum sensing algorithm based on energy detection that increases the reliability of individual spectrum sensing. In spite of the fact that the energy detection is still the most common detection mechanism for spectrum sensing due to its simplicity. Energy detection does not require any prior knowledge of primary signals, but has the drawbacks of threshold selection, and poor performance due to noise uncertainty especially at low SNR. Therefore, a new adaptive optimal energy detection algorithm (AOED) is presented in this thesis. In comparison with the existing energy detection schemes the detection performance achieved through AOED algorithm is higher. Secondly, as cooperative spectrum sensing (CSS) can give further improvement in the detection reliability, the AOED algorithm is extended to cooperative sensing; in which multiple cognitive users collaborate to detect the primary transmission. The new combined approach (AOED and CSS) is shown to be more reliable detection than the individual detection scheme, where the hidden terminal problem can be mitigated. Furthermore, an optimal fusion strategy for hard-fusion based cognitive radio networks is presented, which optimises sensing performance. Thirdly, the need for denser deployment of base stations to satisfy the estimated high traffic demand in future wireless networks leads to a significant increase in energy consumption. Moreover, in large-scale cognitive radio networks some of…
Subjects/Keywords: 621.384; Cognitive radio networks, spectrum sensing, energy detection, cooperative spectrum sensing, cluster based spectrum sensing
Kozal, A. S. B. (2015). Multi user cooperation spectrum sensing in wireless cognitive radio networks . (Doctoral Dissertation). Liverpool John Moores University. Retrieved from https://doi.org/10.24377/LJMU.t.00004474 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.658129
Kozal, Ahmed Sultan Bilal. "Multi user cooperation spectrum sensing in wireless cognitive radio networks." 2015. Doctoral Dissertation, Liverpool John Moores University. Accessed January 21, 2021. https://doi.org/10.24377/LJMU.t.00004474 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.658129.
Kozal, Ahmed Sultan Bilal. "Multi user cooperation spectrum sensing in wireless cognitive radio networks." 2015. Web. 21 Jan 2021.
Kozal ASB. Multi user cooperation spectrum sensing in wireless cognitive radio networks. [Internet] [Doctoral dissertation]. Liverpool John Moores University; 2015. [cited 2021 Jan 21]. Available from: https://doi.org/10.24377/LJMU.t.00004474 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.658129.
Kozal ASB. Multi user cooperation spectrum sensing in wireless cognitive radio networks. [Doctoral Dissertation]. Liverpool John Moores University; 2015. Available from: https://doi.org/10.24377/LJMU.t.00004474 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.658129
2. Shaghluf, Nagwa. Cooperative spectrum prediction for improved efficiency of cognitive radio networks.
Degree: Department of Electrical and Computer Engineering, 2018, University of Victoria
URL: https://dspace.library.uvic.ca//handle/1828/8986
► In this thesis, the spectrum and energy efficiency of cooperative spectrum prediction (CSP) in cognitive radio networks are investigated. In addition, the performance of CSP… (more)
▼ In this thesis, the spectrum and energy efficiency of cooperative spectrum prediction (CSP) in cognitive radio networks are investigated. In addition, the performance of CSP is evaluated using a hidden Markov model (HMM) and a multilayer perceptron (MLP) neural network. The cooperation between secondary users in predicting the next channel status employs AND, OR and majority rule fusion schemes. These schemes are compared for HMM and MLP predictors as a function of channel occupancy in terms of prediction error, spectrum efficiency and energy efficiency. The impact of busy and idle state prediction errors on the spectrum efficiency is determined. Further, the spectrum efficiency is compared for different numbers of primary users (PUs). Simulation results are presented which show a significant improvement in the spectrum efficiency using CSP with the majority rule at the cost of a small degradation in energy efficiency compared to single spectrum prediction (SSP) and traditional spectrum sensing (TSS). The HMM predictor provides better performance than the MLP predictor. Moreover, the total probability of prediction error with the majority rule provides the best performance compared to SSP and the other fusion rules. On the other hand, the AND and OR rules have the worst performance in the high and low traffic cases, respectively. The majority rule provides a good tradeoff between busy and idle state prediction errors compared with the AND and OR rules and SSP. Further, a reduction in the busy state prediction error increases the SE more compared to a reduction in the idle state prediction error. Advisors/Committee Members: Gulliver, T. Aaron (supervisor).
Subjects/Keywords: Spectrum sensing; Cognitive Radio; Single spectrum prediction; Cooperative spectrum prediction; Energy efficiency; Spectrum efficiency
Shaghluf, N. (2018). Cooperative spectrum prediction for improved efficiency of cognitive radio networks . (Masters Thesis). University of Victoria. Retrieved from https://dspace.library.uvic.ca//handle/1828/8986
Shaghluf, Nagwa. "Cooperative spectrum prediction for improved efficiency of cognitive radio networks." 2018. Masters Thesis, University of Victoria. Accessed January 21, 2021. https://dspace.library.uvic.ca//handle/1828/8986.
Shaghluf, Nagwa. "Cooperative spectrum prediction for improved efficiency of cognitive radio networks." 2018. Web. 21 Jan 2021.
Shaghluf N. Cooperative spectrum prediction for improved efficiency of cognitive radio networks. [Internet] [Masters thesis]. University of Victoria; 2018. [cited 2021 Jan 21]. Available from: https://dspace.library.uvic.ca//handle/1828/8986.
Shaghluf N. Cooperative spectrum prediction for improved efficiency of cognitive radio networks. [Masters Thesis]. University of Victoria; 2018. Available from: https://dspace.library.uvic.ca//handle/1828/8986
3. Jiang, Chunxing. Design of Asynchronous Cooperative Spectrum Sensing Scheme and Wideband Dynamic Spectrum Access Algorithm for Cognitive Radio Networks.
URL: https://era.library.ualberta.ca/files/m900nt88m
► Dynamic spectrum access (DSA) is a promising solution for mitigating the problem of crowded radio spectrum and enhancing the utilization efficiency of spectrum resources, making… (more)
▼ Dynamic spectrum access (DSA) is a promising solution for mitigating the problem of crowded radio spectrum and enhancing the utilization efficiency of spectrum resources, making it a hot research topic. In DSA, spectrum sensing is crucial and cooperative spectrum sensing (CSS) is confirmed as a promising technology that can combat the wireless channel fading problem. Most current works have assumed that secondary users (SUs) are synchronous with the primary users' (PUs) network. However, on one hand, the SUs may not have information about the PUs' communication protocols. On the other hand, communications among PUs are not based on synchronous operation in some systems. In order to address such problems, an asynchronous CSS scheme is proposed. Based on this scheme, the DYWAMIT, a contention-based wideband DSA algorithm, is proposed. Performance analysis and simulations are conducted to evaluate the proposed scheme and algorithm. Some important future research challenges are highlighted.
Subjects/Keywords: Cognitive Radio; Dynamic Spectrum Access; Cooperative Spectrum Sensing; Asynchronous
Jiang, C. (2013). Design of Asynchronous Cooperative Spectrum Sensing Scheme and Wideband Dynamic Spectrum Access Algorithm for Cognitive Radio Networks . (Masters Thesis). University of Alberta. Retrieved from https://era.library.ualberta.ca/files/m900nt88m
Jiang, Chunxing. "Design of Asynchronous Cooperative Spectrum Sensing Scheme and Wideband Dynamic Spectrum Access Algorithm for Cognitive Radio Networks." 2013. Masters Thesis, University of Alberta. Accessed January 21, 2021. https://era.library.ualberta.ca/files/m900nt88m.
Jiang, Chunxing. "Design of Asynchronous Cooperative Spectrum Sensing Scheme and Wideband Dynamic Spectrum Access Algorithm for Cognitive Radio Networks." 2013. Web. 21 Jan 2021.
Jiang C. Design of Asynchronous Cooperative Spectrum Sensing Scheme and Wideband Dynamic Spectrum Access Algorithm for Cognitive Radio Networks. [Internet] [Masters thesis]. University of Alberta; 2013. [cited 2021 Jan 21]. Available from: https://era.library.ualberta.ca/files/m900nt88m.
Jiang C. Design of Asynchronous Cooperative Spectrum Sensing Scheme and Wideband Dynamic Spectrum Access Algorithm for Cognitive Radio Networks. [Masters Thesis]. University of Alberta; 2013. Available from: https://era.library.ualberta.ca/files/m900nt88m
4. Zhang, Ning. Security-aware Cooperation in Dynamic Spectrum Access.
► We have witnessed a massive growth in wireless data, which almost doubles every year. The wireless data is expected to skyrocket further in the future… (more)
▼ We have witnessed a massive growth in wireless data, which almost doubles every year. The wireless data is expected to skyrocket further in the future due to the proliferation of devices and the emerging data-hungry applications. To accommodate the explosive growth in mobile traffic, a large amount of wireless spectrum is needed. With the limited spectrum resource, the current static spectrum allocation policy cannot serve well for future wireless systems. Moreover, it exacerbates the spectrum scarcity by resulting in severe spectrum underutilization. As a promising solution, dynamic spectrum access (DSA) is envisaged to increase spectrum efficiency by dynamic sharing all the spectrum. DSA can be enabled by cognitive radio technologies, which allow the unlicensed users (the secondary users, i.e., SUs) to dynamically access the unused spectrum (i.e., spectrum holes) owned by the licensed users (the primary users i.e., PUs). In order to identify the unused spectrum (spectrum holes), unlicensed users need to conduct spectrum sensing. While spectrum sensing might be inaccurate due to multipath fading and shadowing. To address this problem, user cooperation can be leveraged, with two main forms: cooperative spectrum sensing and cooperative cognitive radio networking (CCRN). For the former, SUs cooperate with each other in spectrum sensing to better detect the spectrum holes. For the latter, SUs cooperate with the PUs to gain access opportunities from the PUs by improving the transmission performance of the PUs. Whereas cooperation can also incur security issues, e.g., malicious users might participate into cooperation, corrupting or disrupting the communication of legitimate users, selfish users might refuse to contribute to cooperation for self-interests, etc. Those security issues are of great importance and need to be considered for cooperation in DSA. In this thesis, we study security-aware cooperation in DSA. First, we investigate cooperative spectrum sensing in multi-channel scenario such that a user can be scheduled for spectrum sensing and spectrum sharing. The cooperative framework can achieve a higher average throughput per user, which provides the incentive for selfish users to participate in cooperative spectrum sensing. Second, secure communication in CCRN is studied, where the SUs cooperate with the PU to enhance the latter's communication security and then gain transmission opportunities. Partner selection, spectrum access time allocation, and power allocation are investigated. Third, we study risk aware cooperation based DSA for the multiple channel scenario, where multiple SUs cooperate with multiple PUs for spectrum access opportunities, considering the trustworthiness of SUs. Lastly, we propose an incentive mechanism to stimulate SUs to cooperate with PUs when they have no traffic. The cooperating SUs are motivated to cooperate with PUs to enhance the security of the PUs by accumulating credits and then consume the earned credits for spectrum trading when they have traffic in the future.
Subjects/Keywords: Dynamic spectrum access; cognitive radio; spectrum sensing; cooperative communication
Zhang, N. (2015). Security-aware Cooperation in Dynamic Spectrum Access . (Thesis). University of Waterloo. Retrieved from http://hdl.handle.net/10012/9224
Zhang, Ning. "Security-aware Cooperation in Dynamic Spectrum Access." 2015. Thesis, University of Waterloo. Accessed January 21, 2021. http://hdl.handle.net/10012/9224.
Zhang, Ning. "Security-aware Cooperation in Dynamic Spectrum Access." 2015. Web. 21 Jan 2021.
Zhang N. Security-aware Cooperation in Dynamic Spectrum Access. [Internet] [Thesis]. University of Waterloo; 2015. [cited 2021 Jan 21]. Available from: http://hdl.handle.net/10012/9224.
Zhang N. Security-aware Cooperation in Dynamic Spectrum Access. [Thesis]. University of Waterloo; 2015. Available from: http://hdl.handle.net/10012/9224
5. Prawatmuang, Warit. Cooperative spectrum sensing for cognitive radio.
Degree: PhD, 2013, University of Manchester
URL: https://www.research.manchester.ac.uk/portal/en/theses/cooperative-spectrum-sensing-for-cognitive-radio(db1dd626-841e-4b05-b5af-fa27e59c63bb).html  ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.588147
► Cognitive Radio (CR) aims to access the wireless spectrum in an opportunistic manner while the licensed user is not using it. To accurately determine the… (more)
▼ Cognitive Radio (CR) aims to access the wireless spectrum in an opportunistic manner while the licensed user is not using it. To accurately determine the licensed user's existence, spectrum sensing procedure is vital to CR system. Energy detection-based spectrum sensing techniques is favourable due to its simplicity and low complexity. In addition, to improve the detection performance, cooperative spectrum sensing technique exploits multi-user diversity and mitigates detection uncertainty. In this thesis, we investigate several energy detection based cooperative spectrum sensing techniques.First, the closed-form analysis for the Equal Gain Combining based Soft Decision Combining (EGC-SDC) scheme, in which all CR users forward its observation to the fusion center, is derived. In order to reduce the communication overhead between CR users and the fusion center, we proposed quantized cooperative spectrum sensing technique, in which CR users quantize its local observation before forwarding to the fusion center. Next, the Double Threshold scheme, where some users only forward its local decision while other users forward its observation, is considered and analyzed. To further reduce the communication overhead, we also proposed that quantization is applied to the users who forward its observation. Later on, three sequential cooperative spectrum sensing schemes in time-varying channel are considered. By aggregating past local observations from previous sensing slots, CR users can improve the detection performance. The Weighted Sequential Energy Detector (SED) scheme simply takes fixed number of past local observations, while the other two schemes, Two-Stage SED and Differential SED, adaptively determine the number of observations, based on its decision towards primary user's existence.Simulation results show that the analysis on EGC-SDC scheme is accurate and the quantized cooperative spectrum sensing technique can improve the performance and approach the detection performance of EGC-SDC scheme with much less bandwidth requirement. Also, the Double Threshold scheme can help improve the detection performance over the conventional technique. Furthermore, the analysis on Double Threshold provides a closed-form for the probability of false alarm and detection. Additionally, the sequential spectrum sensing schemes are shown to improve the detection performance and enable CR system to work in scenarios that the conventional technique can not accommodate.
Subjects/Keywords: 621.384; spectrum sensing; cognitive radio; cooperative sensing; energy detection
Prawatmuang, W. (2013). Cooperative spectrum sensing for cognitive radio . (Doctoral Dissertation). University of Manchester. Retrieved from https://www.research.manchester.ac.uk/portal/en/theses/cooperative-spectrum-sensing-for-cognitive-radio(db1dd626-841e-4b05-b5af-fa27e59c63bb).html ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.588147
Prawatmuang, Warit. "Cooperative spectrum sensing for cognitive radio." 2013. Doctoral Dissertation, University of Manchester. Accessed January 21, 2021. https://www.research.manchester.ac.uk/portal/en/theses/cooperative-spectrum-sensing-for-cognitive-radio(db1dd626-841e-4b05-b5af-fa27e59c63bb).html ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.588147.
Prawatmuang, Warit. "Cooperative spectrum sensing for cognitive radio." 2013. Web. 21 Jan 2021.
Prawatmuang W. Cooperative spectrum sensing for cognitive radio. [Internet] [Doctoral dissertation]. University of Manchester; 2013. [cited 2021 Jan 21]. Available from: https://www.research.manchester.ac.uk/portal/en/theses/cooperative-spectrum-sensing-for-cognitive-radio(db1dd626-841e-4b05-b5af-fa27e59c63bb).html ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.588147.
Prawatmuang W. Cooperative spectrum sensing for cognitive radio. [Doctoral Dissertation]. University of Manchester; 2013. Available from: https://www.research.manchester.ac.uk/portal/en/theses/cooperative-spectrum-sensing-for-cognitive-radio(db1dd626-841e-4b05-b5af-fa27e59c63bb).html ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.588147
University of Windsor
6. Awin, Faroq Ali. Energy-efficient spectrum sensing approaches for cognitive radio systems.
Degree: PhD, Electrical and Computer Engineering, 2016, University of Windsor
URL: https://scholar.uwindsor.ca/etd/5902
► Designing an energy efficient cooperative spectrum sensing for cognitive radio network is our main research objective in this dissertation. Two different approaches are employed to… (more)
▼ Designing an energy efficient cooperative spectrum sensing for cognitive radio network is our main research objective in this dissertation. Two different approaches are employed to achieve the goal, clustering and minimizing the number of participating cognitive radio users in the cooperative process. First, using clustering technique, a multilevel hierarchical cluster-based structure spectrum sensing algorithm has been proposed to tackle the balance between cooperation gain and cost by combining two different fusion rules and exploiting the tree structure of the cluster. The algorithm considerably minimizes the reporting overhead while satisfying the detection requirements. Second, based on reducing the number of participating cognitive radio users, primary user protection is considered to develop an energy efficient algorithm for cluster-based cooperative spectrum sensing system. An iterative algorithm with low complexity has been proposed to design energy efficient spectrum sensing for cluster-based cooperative systems. Simulation results show that the proposed algorithm can significantly minimize the number of contributing of cognitive radio users in the collaboration process and can compromise the performance gain and the incurred overhead. Moreover, a variable sensing window size is also considered to propose three novel strategies for energy efficient centralized cooperative spectrum sensing system using the three hard decision fusion rules. The results show that strategies remarkably increase the energy efficiency of the cooperative system; furthermore, it is shown optimality of k out of N rule over other two hard decision fusion rules. Finally, joint optimization of transmission power and sensing time for a single cognitive radio is considered. An iterative algorithm with low computational requirements has been proposed to jointly optimize power and sensing time to maximize the energy efficiency metric. Computer results have shown that the proposed algorithm outperforms those existing works in the literature. Advisors/Committee Members: Abdel-Raheem, Esam, Ahmadi, Majid.
Subjects/Keywords: Cognitive radio; Cooperative spectrum sensing; Detection performance; Energy efficiency; Optimization; Spectrum sensing
Awin, F. A. (2016). Energy-efficient spectrum sensing approaches for cognitive radio systems . (Doctoral Dissertation). University of Windsor. Retrieved from https://scholar.uwindsor.ca/etd/5902
Awin, Faroq Ali. "Energy-efficient spectrum sensing approaches for cognitive radio systems." 2016. Doctoral Dissertation, University of Windsor. Accessed January 21, 2021. https://scholar.uwindsor.ca/etd/5902.
Awin, Faroq Ali. "Energy-efficient spectrum sensing approaches for cognitive radio systems." 2016. Web. 21 Jan 2021.
Awin FA. Energy-efficient spectrum sensing approaches for cognitive radio systems. [Internet] [Doctoral dissertation]. University of Windsor; 2016. [cited 2021 Jan 21]. Available from: https://scholar.uwindsor.ca/etd/5902.
Awin FA. Energy-efficient spectrum sensing approaches for cognitive radio systems. [Doctoral Dissertation]. University of Windsor; 2016. Available from: https://scholar.uwindsor.ca/etd/5902
University of California – Berkeley
7. Mishra, Shridhar Mubaraq. Maximizing available spectrum for cognitive radios.
Degree: Electrical Engineering & Computer Sciences, 2009, University of California – Berkeley
URL: http://www.escholarship.org/uc/item/722103kg
► Cognitive radios have been proposed to address the dual problem of spectrum under-utilization and the need for vast swathes of new spectrum in the 0-3GHz… (more)
▼ Cognitive radios have been proposed to address the dual problem of spectrum under-utilization and the need for vast swathes of new spectrum in the 0-3GHz band for wireless data services. Previous research in the area of cognitive radios has concentrated on signal processing (SP) innovations for improved detection with a limited number of samples (a.k.a detection sensitivity). However the SP perspective alone is unable to recover much unused spectrum. In this thesis we focus on two fronts to maximize the recovery of unused spectrum. First, we take a spatial perspective on spectrum usage. Second, we will look at advanced algorithms which use other radios and frequencies to aid the detection process.The spatial perspective is necessitated by the FCC's decision to open up TV bands for 'white space'/opportunistic spectrum use. Examination of the FCC's choice of parameters reveals the political and engineering tradeoffs made by the FCC. The FCC's rules applied to the database of TV transmitters and the population density of the United States as per the census of 2000 reveal that the geo-location rules enable an average of 9 white space channels per person. This number does not change significantly even if the secondaries take a purely selfish approach and operate only where the pollution from TV transmitters is low. The corresponding political tradeoff sacrifices 1 people-channel for broadcast use to gain 8 people-channels for white space use. Spectrum sensing is another mechanism to recover the available opportunity. Here, the FCC's sensing rule of -114dBm is very conservative and yields only a average of 1 white space channel per person. This spatial analysis points to the inability of traditional detection metrics in predicting the spatial performance of sensing. To overcome this problem, we propose the twin metrics of Fear of Harmful Interference (FHI) and Weighted Probability of Area Recovered (WPAR) to quantify the performance of sensing relative to geo-location. Fear of Harmful interference (FHI), captures the safety to the primary users and is largely the fading-aware probability of missed detection with modifications to allow easier incorporation of system-level uncertainty. Weighted Probability of Area Recovered (WPAR), captures the performance of spectrum sensing by appropriately weighting the probability of false alarm (PFA) across different spatial locations. These metrics give a unifying framework in which to compare different spectrum-sensing algorithms. Reasonable parameters for this metric (most crucially, something which can be interpreted as a spatial discount factor) are obtained from the TV database and US population data. Cooperative Sensing, in which secondaries use sensing results from multiple nearby radios to decide on whether the band is free to use, has been proposed as a mechanism to improve the performance over a single radio. However, the motivation for using cooperative sensing is different for recovering a temporal as opposed to…
Subjects/Keywords: Electrical engineering; cognitive radios; cooperative sensing; multiband sensing; spectrum sensing; white space
Mishra, S. M. (2009). Maximizing available spectrum for cognitive radios . (Thesis). University of California – Berkeley. Retrieved from http://www.escholarship.org/uc/item/722103kg
Mishra, Shridhar Mubaraq. "Maximizing available spectrum for cognitive radios." 2009. Thesis, University of California – Berkeley. Accessed January 21, 2021. http://www.escholarship.org/uc/item/722103kg.
Mishra, Shridhar Mubaraq. "Maximizing available spectrum for cognitive radios." 2009. Web. 21 Jan 2021.
Mishra SM. Maximizing available spectrum for cognitive radios. [Internet] [Thesis]. University of California – Berkeley; 2009. [cited 2021 Jan 21]. Available from: http://www.escholarship.org/uc/item/722103kg.
Mishra SM. Maximizing available spectrum for cognitive radios. [Thesis]. University of California – Berkeley; 2009. Available from: http://www.escholarship.org/uc/item/722103kg
8. Su, Chao-yung. A Novel Cooperative Spectrum Sensing Method with Double Threshold Hybrid Detection in Cognitive Radio Systems.
Degree: Master, Communications Engineering, 2013, NSYSU
► Cognitive radio system has become a better way to improve the efficiency of spectrum usage. In cognitive radio, spectrum sensing plays a key role. However,… (more)
▼ Cognitive radio system has become a better way to improve the efficiency of spectrum usage. In cognitive radio, spectrum sensing plays a key role. However, the secondary users cannot detect the existence of the primary due the shadowing effectãfading channelsãand multipath fading. To solve these problems, cooperative spectrum sensing has been proposed. For the conventional cooperative spectrum sensing system, when the number of the secondary users is large and environment exists noise uncertainty. The sensing performance would be loss. It shown that conventional cooperative spectrum sensing system seems not a good method. ããIn this thesis, we combine the statistical covariance algorithms to the conventional double thresholds cooperative energy detection and also proposed a method which can reduce the computation complexity for the hybrid detection. Simulation results show that, under the same false alarm probability, the proposed hybrid scheme achieves much better detection performance than conventional energy detection. Advisors/Committee Members: Sen-Hung Wang (chair), Char-Dir Chung (chair), Chin-liang Wang (chair), Jyh-Horng Wen (chair), Chih-Peng Li (committee member).
Subjects/Keywords: cooperative double threshold energy detection; cooperative spectrum sensing; Cognitive radio; statistical covariance algorithm
Su, C. (2013). A Novel Cooperative Spectrum Sensing Method with Double Threshold Hybrid Detection in Cognitive Radio Systems . (Thesis). NSYSU. Retrieved from http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0805113-142840
Su, Chao-yung. "A Novel Cooperative Spectrum Sensing Method with Double Threshold Hybrid Detection in Cognitive Radio Systems." 2013. Thesis, NSYSU. Accessed January 21, 2021. http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0805113-142840.
Su, Chao-yung. "A Novel Cooperative Spectrum Sensing Method with Double Threshold Hybrid Detection in Cognitive Radio Systems." 2013. Web. 21 Jan 2021.
Su C. A Novel Cooperative Spectrum Sensing Method with Double Threshold Hybrid Detection in Cognitive Radio Systems. [Internet] [Thesis]. NSYSU; 2013. [cited 2021 Jan 21]. Available from: http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0805113-142840.
Su C. A Novel Cooperative Spectrum Sensing Method with Double Threshold Hybrid Detection in Cognitive Radio Systems. [Thesis]. NSYSU; 2013. Available from: http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0805113-142840
9. Jafri, Ghayoor Abbas; Rehman, Ateeq Ur. Spectrum Sensing and Management in Cooperative Cognitive Radio.
Degree: 2011, , School of Engineering
URL: http://urn.kb.se/resolve?urn=urn:nbn:se:bth-3245
In the last few years, there has been enormous improvement in mobile communication services. Due to this rapid growth in the field of communications,… (more)
In the last few years, there has been enormous improvement in mobile communication services. Due to this rapid growth in the field of communications, the demand for wireless spectrum has increased rapidly. In the early days in order to remove the interference problem, the spectrum was assigned statically. To assign the spectrum statically, the fixed spectrum assignment policy was used. Due to the fixed spectrum assignment policy, the spectrum was not efficiently utilized and remained vacant most of the time. The study by Federal Communications Commission (FCC) shows that the spectrum is available but its usage is not efficient. Such kind of spectrum inefficiency can be overcome by the use of Cognitive Radio. Cognitive Radio is a new technology that allows the secondary users (SUs) to use the spectrum whenever it is available. In this thesis, an Opportunistic Cognitive MAC Protocol (OC-MAC) has been proposed for the Cognitive Radio to access the unoccupied spectrum opportunistically and coexistence with the ad hoc Wireless Local Area Network (WLAN). OC-MAC is a decentralized MAC protocol over Cognitive Radio network along with WLAN. In the OC-MAC protocol, there is a dedicated control channel over which the cognitive nodes compete with each other for the reservation of the data channel. The handshaking phenomenon for the reservation of data channels is performed on the control channel. After a selection of the appropriate data channel, when a secondary user starts using the data channel and the primary user claims it, the SU leaves the spectrum and moves to another available channel. The transmission of data by the secondary user is confirmed by receiving an acknowledgement. In this way secondary user utilizes the unused frequency spectrum while maintaining acceptable collision rate among secondary users and between secondary users and primary users. All simulation scenarios are developed in OPNET v14.5 Network simulator and simulation results are collected for different scenarios; under light and heavy traffic to check the performance of the OC-MAC protocol.
Subjects/Keywords: Cognitive radio networks; Cooperative communication; Dynamic spectrum sharing; Cross layer design; OC-MAC Protocol; Opportunistic spectrum access; Spectrum sensing; Spectrum management
Jafri, Ghayoor Abbas; Rehman, A. U. (2011). Spectrum Sensing and Management in Cooperative Cognitive Radio . (Thesis). , School of Engineering. Retrieved from http://urn.kb.se/resolve?urn=urn:nbn:se:bth-3245
Jafri, Ghayoor Abbas; Rehman, Ateeq Ur. "Spectrum Sensing and Management in Cooperative Cognitive Radio." 2011. Thesis, , School of Engineering. Accessed January 21, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-3245.
Jafri, Ghayoor Abbas; Rehman, Ateeq Ur. "Spectrum Sensing and Management in Cooperative Cognitive Radio." 2011. Web. 21 Jan 2021.
Jafri, Ghayoor Abbas; Rehman AU. Spectrum Sensing and Management in Cooperative Cognitive Radio. [Internet] [Thesis]. , School of Engineering; 2011. [cited 2021 Jan 21]. Available from: http://urn.kb.se/resolve?urn=urn:nbn:se:bth-3245.
Jafri, Ghayoor Abbas; Rehman AU. Spectrum Sensing and Management in Cooperative Cognitive Radio. [Thesis]. , School of Engineering; 2011. Available from: http://urn.kb.se/resolve?urn=urn:nbn:se:bth-3245
10. Kataka, Matsanza Edwin. Energy efficient cooperative spectrum sensing techniques in cognitive radio networks.
Degree: 2017, University of KwaZulu-Natal
URL: https://researchspace.ukzn.ac.za/handle/10413/17261
► The demand for spectrum is increasing particularly due to the accelerating growth in wireless data traffic generated by smart phones, tablets and other internet access… (more)
▼ The demand for spectrum is increasing particularly due to the accelerating growth in wireless data traffic generated by smart phones, tablets and other internet access devices. Most of prime spectrum is already licensed. The licensed spectrum is underutilized or used inefficiently, i.e. spectrum sits idle at any given time and location. Opportunistic Spectrum Access (OSA) is proposed as a solution to provide access to the temporarily unused spectrum commonly known as white spaces to improve spectrum utilization, increase spectrum efficiency and reduce spectrum scarcity. The aim of this research is to investigate potential impact of cooperative spectrum sensing techniques technologies on spectrum management. To fulfill this we focused on two spectrum sensing techniques namely; Firstly energy efficient statistical cooperative spectrum sensing in cognitive radio networks, this work exploits the higher order statistical (HOS) tests to detect the status of PU signal by a group of SUs. Secondly, an optimal energy based cooperative spectrum sensing in cognitive radio networks was investigated. In this work the performance of optimal hard fusion rules are employed in SU's selection criteria and fusion of the decisions under Gaussian channel and Rayleigh channels. To optimize on the energy a two stage fusion and selection strategy is adopted to minimize the number of collaborating SUs. Advisors/Committee Members: Walingo, Tom Mmbasu, (advisor).
Subjects/Keywords: Energy efficient.; Cooperative spectrum.; Sensing techniques.; Cognitive radio networks.; Accelerating growth.
Kataka, M. E. (2017). Energy efficient cooperative spectrum sensing techniques in cognitive radio networks. (Thesis). University of KwaZulu-Natal. Retrieved from https://researchspace.ukzn.ac.za/handle/10413/17261
Kataka, Matsanza Edwin. "Energy efficient cooperative spectrum sensing techniques in cognitive radio networks." 2017. Thesis, University of KwaZulu-Natal. Accessed January 21, 2021. https://researchspace.ukzn.ac.za/handle/10413/17261.
Kataka, Matsanza Edwin. "Energy efficient cooperative spectrum sensing techniques in cognitive radio networks." 2017. Web. 21 Jan 2021.
Kataka ME. Energy efficient cooperative spectrum sensing techniques in cognitive radio networks. [Internet] [Thesis]. University of KwaZulu-Natal; 2017. [cited 2021 Jan 21]. Available from: https://researchspace.ukzn.ac.za/handle/10413/17261.
Kataka ME. Energy efficient cooperative spectrum sensing techniques in cognitive radio networks. [Thesis]. University of KwaZulu-Natal; 2017. Available from: https://researchspace.ukzn.ac.za/handle/10413/17261
11. Sohul, Munawwar Mahmud. PERFORMANCE OF LINEAR DECISION COMBINER FOR PRIMARY USER DETECTION IN COGNITIVE RADIO.
Degree: MS, Electrical and Computer Engineering, 2011, Southern Illinois University
URL: https://opensiuc.lib.siu.edu/theses/705
► The successful implementation and employment of various cognitive radio services are largely dependent on the spectrum sensing performance of the cognitive radio terminals. Previous… (more)
▼ The successful implementation and employment of various cognitive radio services are largely dependent on the spectrum sensing performance of the cognitive radio terminals. Previous works on detection of cognitive radio have suggested the necessity of user cooperation in order to be able to detect at low signal-to-noise ratios experienced in practical situations. This report provides a brief overview of the impact of different fusion strategies on the spectrum hole detection performance of a fusion center in a distributed detection environment. Different decision or detection rule and fusion strategies, like single sensor scenario, counting rule, and linear decision metric, were used to analyze their influence on the spectrum sensing performance of the cognitive radio network. We consider a system of cognitive radio users who cooperate with each other in trying to detect licensed transmissions. Assuming that the cooperating nodes use identical energy detectors, we model the received signals as correlated log-normal random variables and study the problem of fusing the decisions made by the individual nodes. The cooperating radios were assumed to be designed in such a way that they satisfy the interference probability constraint individually. The interference probability constraint was also met at the fusion center. The simulation results strongly suggests that even when the observations at the individual sensors are moderately correlated, it is important not to ignore the correlation between the nodes for fusing the local decisions made by the secondary users. The thesis mainly focuses on the performance measurement of linear decision combiner in detecting primary users in a cognitive radio network. Advisors/Committee Members: Viswanathan, Ramanarayanan.
Subjects/Keywords: Cognitive Radio; Cooperative Spectrum Sensing; Correlated Shadowing; Interference Probability Constraint
Sohul, M. M. (2011). PERFORMANCE OF LINEAR DECISION COMBINER FOR PRIMARY USER DETECTION IN COGNITIVE RADIO . (Masters Thesis). Southern Illinois University. Retrieved from https://opensiuc.lib.siu.edu/theses/705
Sohul, Munawwar Mahmud. "PERFORMANCE OF LINEAR DECISION COMBINER FOR PRIMARY USER DETECTION IN COGNITIVE RADIO." 2011. Masters Thesis, Southern Illinois University. Accessed January 21, 2021. https://opensiuc.lib.siu.edu/theses/705.
Sohul, Munawwar Mahmud. "PERFORMANCE OF LINEAR DECISION COMBINER FOR PRIMARY USER DETECTION IN COGNITIVE RADIO." 2011. Web. 21 Jan 2021.
Sohul MM. PERFORMANCE OF LINEAR DECISION COMBINER FOR PRIMARY USER DETECTION IN COGNITIVE RADIO. [Internet] [Masters thesis]. Southern Illinois University; 2011. [cited 2021 Jan 21]. Available from: https://opensiuc.lib.siu.edu/theses/705.
Sohul MM. PERFORMANCE OF LINEAR DECISION COMBINER FOR PRIMARY USER DETECTION IN COGNITIVE RADIO. [Masters Thesis]. Southern Illinois University; 2011. Available from: https://opensiuc.lib.siu.edu/theses/705
▼ The demand for spectrum is increasing particularly due to the accelerating growth in wireless data traffic generated by smart phones, tablets and other internet access devices. Most of prime spectrum is already licensed. The licensed spectrum is underutilized or used inefficiently, i.e. spectrum sits idle at any given time and location. Opportunistic Spectrum Access (OSA) is proposed as a solution to provide access to the temporarily unused spectrum commonly known as white spaces to improve spectrum utilization, increase spectrum efficiency and reduce spectrum scarcity. The aim of this research is to investigate potential impact of cooperative spectrum sensing techniques technologies on spectrum management. To fulfill this we focused on two spectrum sensing techniques namely; Firstly energy efficient statistical cooperative spectrum sensing in cognitive radio networks, this work exploits the higher order statistical (HOS) tests to detect the status of PU signal by a group of SUs. Secondly, an optimal energy based cooperative spectrum sensing in cognitive radio networks was investigated. In this work the performance of optimal hard fusion rules are employed in SU's selection criteria and fusion of the decisions under Gaussian channel and Rayleigh channels. To optimize on the energy a two stage fusion and selection strategy is adopted to minimize the number of collaborating SUs. Advisors/Committee Members: Walingo, Tom Mmbasu. (advisor).
Subjects/Keywords: Theses - Electronic Engineering.; Spectrum sensing.; Cognitive radio.; Energy detection schemes.; Cooperative sensing.
Kataka, M. E. (2017). Energy efficient cooperative spectrum sensing techniques in cognitive radio networks. (Thesis). University of KwaZulu-Natal. Retrieved from http://hdl.handle.net/10413/15684
Kataka, Matsanza Edwin. "Energy efficient cooperative spectrum sensing techniques in cognitive radio networks." 2017. Thesis, University of KwaZulu-Natal. Accessed January 21, 2021. http://hdl.handle.net/10413/15684.
Kataka ME. Energy efficient cooperative spectrum sensing techniques in cognitive radio networks. [Internet] [Thesis]. University of KwaZulu-Natal; 2017. [cited 2021 Jan 21]. Available from: http://hdl.handle.net/10413/15684.
Kataka ME. Energy efficient cooperative spectrum sensing techniques in cognitive radio networks. [Thesis]. University of KwaZulu-Natal; 2017. Available from: http://hdl.handle.net/10413/15684
13. Elgadi, Refga. An Intelligent Multi-stage Channel Acquisition Model for CR-WBANs: A Context Aware Approach.
► Cognitive Radio (CR) came as a solution to mitigate challenges that wireless body area networks (WBANs) suffer from. CR is an intelligence-based technology that senses,… (more)
▼ Cognitive Radio (CR) came as a solution to mitigate challenges that wireless body area networks (WBANs) suffer from. CR is an intelligence-based technology that senses, observes, and learns from its operating environment to access licensed bands in the spectrum when they are not being utilized by primary users. Deploying a CR technology in WBANs applications, enhances spectrum scalability, increases system robustness, and decreases latency. Accordingly, CR-WBANs help in building a more efficient and reliable ubiquitous healthcare system than conventional WBANs do. However, CR-WBANs are still evolving, and many challenges need to be investigated, in particular, is how to acquire a channel and prioritize data streams among multiple CR-users (i.e., multiple patients) based on the severity of their health status, in a manner to decrease network latency and increase network scalability. To address this challenge, this work proposes a novel intelligent channel acquisition model for multiple CR-WBANs within ubiquitous healthcare system, whereby contextual data, namely, channel properties, intra-node characteristics, and patients' profile information, is integrated in channel acquisition decision process. The proposed work is a multi-stage fusion system that is composed of local and global decisions units. A fuzzy logic system is utilized to make decisions in the local unit, which are sensing the channel availability and assessing the severity of patients' health status. Moreover, a neural network is employed as a global sensing decision center, whereby local sensing decisions, channel properties, and intra-node characteristics are augmented in the decision process. Furthermore, a cluster-based heuristic algorithm is formulated, in the global decision unit, to prioritize data streams among CR-users based on the criticality of their health conditions (i.e., acute, urgent, and normal). Patients' local health assessments and avatars (e.g., age, medical history, etc.) are exploited in the prioritization process.
Subjects/Keywords: channel acquisition.; hybrid cooperative spectrum sensing.; data transmission prioritization.; fuzzy logic.; neural network.; spectrum sensing accuracy; probability of channel acquisition.
Elgadi, R. (2017). An Intelligent Multi-stage Channel Acquisition Model for CR-WBANs: A Context Aware Approach . (Thesis). University of Waterloo. Retrieved from http://hdl.handle.net/10012/12094
Elgadi, Refga. "An Intelligent Multi-stage Channel Acquisition Model for CR-WBANs: A Context Aware Approach." 2017. Thesis, University of Waterloo. Accessed January 21, 2021. http://hdl.handle.net/10012/12094.
Elgadi, Refga. "An Intelligent Multi-stage Channel Acquisition Model for CR-WBANs: A Context Aware Approach." 2017. Web. 21 Jan 2021.
Elgadi R. An Intelligent Multi-stage Channel Acquisition Model for CR-WBANs: A Context Aware Approach. [Internet] [Thesis]. University of Waterloo; 2017. [cited 2021 Jan 21]. Available from: http://hdl.handle.net/10012/12094.
Elgadi R. An Intelligent Multi-stage Channel Acquisition Model for CR-WBANs: A Context Aware Approach. [Thesis]. University of Waterloo; 2017. Available from: http://hdl.handle.net/10012/12094
14. Treeumnuk, Dusadee. Enhancing Spectrum Utilization in Dynamic Cognitive Radio Systems.
Degree: PhD, Electrical/Computer Engineering, 2012, Old Dominion University
URL: 9781267837196 ; https://digitalcommons.odu.edu/ece_etds/136
► Cognitive radio (CR) is regarded as a viable solution to enabling flexible use of the frequency spectrum in future generations of wireless systems by… (more)
▼ Cognitive radio (CR) is regarded as a viable solution to enabling flexible use of the frequency spectrum in future generations of wireless systems by allowing unlicensed secondary users (SU) to access licensed spectrum under the specific condition that no harmful interference be caused to the licensed primary users (PU) of the spectrum. In practical scenarios, the knowledge of PU activity is unknown to CRs and radio environments are mostly imperfect due to various issues such as noise uncertainty and multipath fadings. Therefore, important functionalities of CR systems are to efficiently detect availability of radio spectrum as well as to avoid generating interference to PUs, by missing detection of active PU signals. Typically, CR systems are expected to be equipped with smart capabilities which include sensing, adapting, learning, and awareness concerned with spectrum opportunity access, radio environments, and wireless communications operations, such that SUs equipped with CRs can efficiently utilize spectrum opportunities with high quality of services. Most existing researches working on CR focus on improving spectrum sensing through performance measures such as the probabilities of PU detection and false alarm but none of them explicitly studies the improvement in the actual spectrum utilization. Motivated by this perspective, the main objective of the dissertation is to explore new techniques on the physical layer of dynamic CR systems, that can enhance actual utilization of spectrum opportunities and awareness on the performance of CR systems. Specifically, this dissertation investigates utilization of spectrum opportunities in dynamic scenarios, where a licensed radio spectrum is available for limited time and also analyzes how it is affected by various parameters. The dissertation proposes three new methods for adaptive spectrum sensing which improve dynamic utilization of idle radio spectrum as well as the detection of active PUs in comparison to the conventional method with fixed spectrum sensing size. Moreover, this dissertation presents a new approach for optimizing cooperative spectrum sensing performance and also proposes the use of hidden Markov models (HMMs) to enabling performance awareness for local and cooperative spectrum sensing schemes, leading to improved spectrum utilization. All the contributions are illustrated with numerical results obtained from extensive simulations which confirm their effectiveness for practical applications. Advisors/Committee Members: Dimitrie C. Popescu, Jiang Li, Linda L. Vahala, Hideaki Kaneko.
Subjects/Keywords: Cognitive radio; Cooperative sensing; Energy detection; Spectrum sensing; Spectrum utilization; Computer Engineering; Electrical and Computer Engineering
Treeumnuk, D. (2012). Enhancing Spectrum Utilization in Dynamic Cognitive Radio Systems . (Doctoral Dissertation). Old Dominion University. Retrieved from 9781267837196 ; https://digitalcommons.odu.edu/ece_etds/136
Treeumnuk, Dusadee. "Enhancing Spectrum Utilization in Dynamic Cognitive Radio Systems." 2012. Doctoral Dissertation, Old Dominion University. Accessed January 21, 2021. 9781267837196 ; https://digitalcommons.odu.edu/ece_etds/136.
Treeumnuk, Dusadee. "Enhancing Spectrum Utilization in Dynamic Cognitive Radio Systems." 2012. Web. 21 Jan 2021.
Treeumnuk D. Enhancing Spectrum Utilization in Dynamic Cognitive Radio Systems. [Internet] [Doctoral dissertation]. Old Dominion University; 2012. [cited 2021 Jan 21]. Available from: 9781267837196 ; https://digitalcommons.odu.edu/ece_etds/136.
Treeumnuk D. Enhancing Spectrum Utilization in Dynamic Cognitive Radio Systems. [Doctoral Dissertation]. Old Dominion University; 2012. Available from: 9781267837196 ; https://digitalcommons.odu.edu/ece_etds/136
15. Celik, Abdulkadir. Green cooperative spectrum sensing and scheduling in heterogeneous cognitive radio networks.
► The motivation behind the cognitive radio networks (CRNs) is rooted in scarcity of the radio spectrum and inefficiency of its management to meet the ever… (more)
▼ The motivation behind the cognitive radio networks (CRNs) is rooted in scarcity of the radio spectrum and inefficiency of its management to meet the ever increasing high quality of service demands. Furthermore, information and communication technologies have limited and/or expensive energy resources and contribute significantly to the global carbon footprint. To alleviate these issues, energy efficient and energy harvesting (EEH) CRNs can harvest the required energy from ambient renewable sources while collecting the necessary bandwidth by discovering free spectrum for a minimized energy cost. Therefore, EEH-CRNs have potential to achieve green communications by enabling spectrum and energy self-sustaining networks. In this thesis, green cooperative spectrum sensing (CSS) policies are considered for large scale heterogeneous CRNs which consist of multiple primary channels (PCs) and a large number of secondary users (SUs) with heterogeneous sensing and reporting channel qualities. Firstly, a multi-objective clustering optimization (MOCO) problem is formulated from macro and micro perspectives; Macro perspective partitions SUs into clusters with the objectives: 1) Intra-cluster energy minimization of each cluster, 2) Intra-cluster throughput maximization of each cluster, and 3) Inter-cluster energy and throughput fairness. A multi-objective genetic algorithm, Non-dominated Sorting Genetic Algorithm-II (NSGA-II), is adopted and demonstrated how to solve the MOCO. The micro perspective, on the other hand, works as a sub-procedure on cluster formations given by macro perspective. For the micro perspective, a multihop reporting based CH selection procedure is proposed to find: 1) The best CH which gives the minimum total multi-hop error rate, and 2) the optimal routing paths from SUs to the CHs using Dijkstra's algorithm. Using Poisson-Binomial distribution, a novel and generalized K-out-of-N voting rule is developed for heterogeneous CRNs to allow SUs to have different levels of local detection performance. Then, a convex optimization framework is established to minimize the intra-cluster energy cost subject to collision and spectrum utilization constraints.Likewise, instead of a common fixed sample size test, a weighted sample size test is considered for quantized soft decision fusion to obtain a more EE regime under heterogeneity. Secondly, an energy and spectrum efficient CSS scheduling (CSSS) problem is investigated to minimize the energy cost per achieved data rate subject to collision and spectrum utilization constraints. The total energy cost is calculated as the sum of energy expenditures resulting from sensing, reporting and channel switching operations. Then, a mixed integer non-linear programming problem is formulated to determine: 1) The optimal scheduling subset of a large number of PCs which cannot be sensed at the same time, 2) The SU assignment set for each scheduled PC, and 3) Optimal sensing parameters of SUs on each PC. Thereafter, an equivalent convex framework is developed for specific instances of…
Subjects/Keywords: Electrical Engineering; Computer Engineering; Cognitive Radio Networks; Cooperative Spectrum Sensing; Cooperative Spectrum Sensing Scheduling; Energy Harvesting; Green Communications; Heterogeneous Networks; Computer Engineering; Computer Sciences; Electrical and Electronics
Celik, A. (2016). Green cooperative spectrum sensing and scheduling in heterogeneous cognitive radio networks . (Thesis). Iowa State University. Retrieved from https://lib.dr.iastate.edu/etd/15126
Celik, Abdulkadir. "Green cooperative spectrum sensing and scheduling in heterogeneous cognitive radio networks." 2016. Thesis, Iowa State University. Accessed January 21, 2021. https://lib.dr.iastate.edu/etd/15126.
Celik, Abdulkadir. "Green cooperative spectrum sensing and scheduling in heterogeneous cognitive radio networks." 2016. Web. 21 Jan 2021.
Celik A. Green cooperative spectrum sensing and scheduling in heterogeneous cognitive radio networks. [Internet] [Thesis]. Iowa State University; 2016. [cited 2021 Jan 21]. Available from: https://lib.dr.iastate.edu/etd/15126.
Celik A. Green cooperative spectrum sensing and scheduling in heterogeneous cognitive radio networks. [Thesis]. Iowa State University; 2016. Available from: https://lib.dr.iastate.edu/etd/15126
16. Jackson, David S. Rogue Signal Threat on Trust-based Cooperative Spectrum Sensing in Cognitive Radio Networks.
Degree: PhD, Computer Science, 2015, Virginia Commonwealth University
URL: https://doi.org/10.25772/K9X2-3034  ; https://scholarscompass.vcu.edu/etd/3925
► Cognitive Radio Networks (CRNs) are a next generation network that is expected to solve the wireless spectrum shortage problem, which is the shrinking of… (more)
▼ Cognitive Radio Networks (CRNs) are a next generation network that is expected to solve the wireless spectrum shortage problem, which is the shrinking of available wireless spectrum resources needed to facilitate future wireless applications. The first CRN standard, the IEEE 802.22, addresses this particular problem by allowing CRNs to share geographically unused TV spectrum to mitigate the spectrum shortage. Equipped with reasoning and learning engines, cognitive radios operate autonomously to locate unused channels to maximize its own bandwidth and Quality-of-Service (QoS). However, their increased capabilities over traditional radios introduce a new dimension of security threats. In an NSF 2009 workshop, the FCC raised the question, "What authentication mechanisms are needed to support cooperative cognitive radio networks? Are reputation-based schemes useful supplements to conventional Public Key Infrastructure (PKI) authentication protocols?" Reputation-based schemes in cognitive radio networks are a popular technique for performing robust and accurate spectrum sensing without any inter-communication with licensed networks, but the question remains on how effective they are at satisfying the FCC security requirements. Our work demonstrates that trust-based Cooperative Spectrum Sensing (CSS) protocols are vulnerable to rogue signals, which creates the illusion of inside attackers and raises the concern that such schemes are overly sensitive Intrusion Detection Systems (IDS). The erosion of the sensor reputations in trust-based CSS protocols makes CRNs vulnerable to future attacks. To counter this new threat, we introduce community detection and cluster analytics to detect and negate the impact of rogue signals on sensor reputations. Advisors/Committee Members: Meng Yu, Wanyu Zang, Wei Cheng, Thang Dinh, Wei Zhang, Qijun Gu.
Subjects/Keywords: cognitive radio networks; cooperative spectrum sensing; rogue signal; trust model; sensor reputation; Computer Engineering
Jackson, D. S. (2015). Rogue Signal Threat on Trust-based Cooperative Spectrum Sensing in Cognitive Radio Networks . (Doctoral Dissertation). Virginia Commonwealth University. Retrieved from https://doi.org/10.25772/K9X2-3034 ; https://scholarscompass.vcu.edu/etd/3925
Jackson, David S. "Rogue Signal Threat on Trust-based Cooperative Spectrum Sensing in Cognitive Radio Networks." 2015. Doctoral Dissertation, Virginia Commonwealth University. Accessed January 21, 2021. https://doi.org/10.25772/K9X2-3034 ; https://scholarscompass.vcu.edu/etd/3925.
Jackson, David S. "Rogue Signal Threat on Trust-based Cooperative Spectrum Sensing in Cognitive Radio Networks." 2015. Web. 21 Jan 2021.
Jackson DS. Rogue Signal Threat on Trust-based Cooperative Spectrum Sensing in Cognitive Radio Networks. [Internet] [Doctoral dissertation]. Virginia Commonwealth University; 2015. [cited 2021 Jan 21]. Available from: https://doi.org/10.25772/K9X2-3034 ; https://scholarscompass.vcu.edu/etd/3925.
Jackson DS. Rogue Signal Threat on Trust-based Cooperative Spectrum Sensing in Cognitive Radio Networks. [Doctoral Dissertation]. Virginia Commonwealth University; 2015. Available from: https://doi.org/10.25772/K9X2-3034 ; https://scholarscompass.vcu.edu/etd/3925
17. Kasiri Mashhad, Behzad. Providing Efficient and Secure Cooperative Spectrum Sensing for Multi-Channel Cognitive Radio Networks.
Degree: Electrical and Computer Engineering, 2013, University of Manitoba
► The focus of this thesis is on cooperative spectrum sensing and related security issues in multi-channel cognitive radio networks (MCCRNs). We first study the channel… (more)
▼ The focus of this thesis is on cooperative spectrum sensing and related security issues in multi-channel cognitive radio networks (MCCRNs). We first study the channel assignment for cooperative spectrum sensing in MCCRNs to maximize the number of available channels. In centralized implementation, a heuristic scheme is proposed along with a greedy scheme to reduce the reported information from the cognitive radios (CRs). In distributed scenario, a novel scheme with multi-round operation is designed following the coalitional game theory. Next, we focus on the physical layer security issues for cooperative spectrum sensing in MCCRNs, caused by Byzantine attacks. New counterattacks are proposed to combat attacks comprising coalition head and CRs as Byzantine attackers, which target to reduce the number of available channels for sensing in distributed MCCRNs. First, a new secure coalition head selection is proposed, by using statistical properties of the exchanged SNRs in the coalitions. Then, an iterative algorithm is proposed to block out attackers, if they continue attacking the system. The important problem of key management is considered next, and an energy-efficient identity-based and a certificate-based distributed key management schemes are proposed. First, a new elliptic curve cryptography (ECC)-based distributed private key generation scheme is proposed to combat the single point of failure problem along with novel distributed private key generator (DPKG) selection schemes to preserve security and energy-efficiency. Because of its importance in the proposed identity-based key management scheme, we further propose a low-complexity DPKG assignment, based on multi-objective programming, which can capture DPKG fairness in addition to energy-efficiency. Finally, a more powerful and intelligent distributed cooperative Byzantine attack on the proposed multi-channel cooperative spectrum sensing is proposed, where attackers collude by applying coalitional game theory to maximize the number of invaded channels in a distributed manner. As a remedy, a hierarchical identity-based key management scheme is proposed, in which CRs can only play on a certain number of requested channels and channel access for sensing is limited to the honest CRs selected in the coalitional game. Simulation results show that the proposed schemes can significantly improve cooperative spectrum sensing and secure the system against Byzantine attacks. Advisors/Committee Members: Cai, Jun (Electrical and Computer Engineering) Alfa, Attahiru S. (Electrical and Computer Engineering) (supervisor), Yahampath, Pradeepa (Electrical and Computer Engineering) Wang, Xikui (Statistics) Cheng, Yu (Illinois Institute of Technology) (examiningcommittee).
Subjects/Keywords: multi-channel cognitive radio networks; cooperative spectrum sensing; coalitional game theory; key management
Kasiri Mashhad, B. (2013). Providing Efficient and Secure Cooperative Spectrum Sensing for Multi-Channel Cognitive Radio Networks . (Thesis). University of Manitoba. Retrieved from http://hdl.handle.net/1993/23228
Kasiri Mashhad, Behzad. "Providing Efficient and Secure Cooperative Spectrum Sensing for Multi-Channel Cognitive Radio Networks." 2013. Thesis, University of Manitoba. Accessed January 21, 2021. http://hdl.handle.net/1993/23228.
Kasiri Mashhad, Behzad. "Providing Efficient and Secure Cooperative Spectrum Sensing for Multi-Channel Cognitive Radio Networks." 2013. Web. 21 Jan 2021.
Kasiri Mashhad B. Providing Efficient and Secure Cooperative Spectrum Sensing for Multi-Channel Cognitive Radio Networks. [Internet] [Thesis]. University of Manitoba; 2013. [cited 2021 Jan 21]. Available from: http://hdl.handle.net/1993/23228.
Kasiri Mashhad B. Providing Efficient and Secure Cooperative Spectrum Sensing for Multi-Channel Cognitive Radio Networks. [Thesis]. University of Manitoba; 2013. Available from: http://hdl.handle.net/1993/23228
18. Do, Tuan T. Joint spatial-temporal spectrum sensing and cooperative relaying for cognitive radio networks .
Degree: 2011, George Mason University
► The number of wireless systems and services has grown tremendously over the last two decades. As a result, the availability of wireless spectrum has become… (more)
▼ The number of wireless systems and services has grown tremendously over the last two decades. As a result, the availability of wireless spectrum has become extremely limited. Cognitive radio is a new technique to overcome the issue of spectrum scarcity. In cognitive radio networks, the licensed users of the spectrum are called primary users. Secondary users equipped with cognitive radios can opportunistically transmit via so-called "spectrum holes" which can be categorized as spatial or temporal spectrum holes. In this dissertation, we propose a joint spatial-temporal spectrum sensing scheme for cognitive radios. We show that our joint spatial-temporal spectrum sensing scheme outperforms pure temporal sensing schemes. In addition, joint spatial-temporal sensing increases the point-to-point transmission capacity of cognitive radio link compared to pure temporal or spatial sensing. We also propose a temporal spectrum sensing scheme that exploits multiuser diversity in wireless networks. In wireless networks with fading, multiuser diversity exists because different users experience peak channel quality at different times. By exploiting multiuser diversity, our spectrum sensing method can outperform the spectrum sensing schemes that do not exploit multiuser diversity. We develop and analyze a joint spatial-temporal sensing scheme that incorporates cooperative relaying to further increase the capacity of a cognitive radio network. We consider both amplify-and-forward and decode-and-forward cooperative transmission strategies. Finally, we study joint spatialtemporal spectrum sensing in a multichannel cognitive radio scenario and present randomized and maximized signal-to-noise ratio algorithms that improve performance in term of symbol error probability. Advisors/Committee Members: Mark, Brian L (advisor).
Subjects/Keywords: Cognitive Radio; Spectrum Sensing; Cooperative Diversity; Turbo Code; Multiuser Diversity; Multichannel Cognitive Radio
Do, T. T. (2011). Joint spatial-temporal spectrum sensing and cooperative relaying for cognitive radio networks . (Thesis). George Mason University. Retrieved from http://hdl.handle.net/1920/6342
Do, Tuan T. "Joint spatial-temporal spectrum sensing and cooperative relaying for cognitive radio networks ." 2011. Thesis, George Mason University. Accessed January 21, 2021. http://hdl.handle.net/1920/6342.
Do, Tuan T. "Joint spatial-temporal spectrum sensing and cooperative relaying for cognitive radio networks ." 2011. Web. 21 Jan 2021.
Do TT. Joint spatial-temporal spectrum sensing and cooperative relaying for cognitive radio networks . [Internet] [Thesis]. George Mason University; 2011. [cited 2021 Jan 21]. Available from: http://hdl.handle.net/1920/6342.
Do TT. Joint spatial-temporal spectrum sensing and cooperative relaying for cognitive radio networks . [Thesis]. George Mason University; 2011. Available from: http://hdl.handle.net/1920/6342
19. Ahmed, Ahmed Mohamed Abdelsalam. Random Medium Access Decision-Based Cooperative Spectrum Sensing for Cognitive Radio Vehicular Ad-hoc Networks .
Degree: 2020, University of Ottawa
► In this thesis, the performance of decision-based Cooperative Spectrum Sensing (CSS) using random medium access sequential reporting assuming an imperfect reporting channel shared with a… (more)
▼ In this thesis, the performance of decision-based Cooperative Spectrum Sensing (CSS) using random medium access sequential reporting assuming an imperfect reporting channel shared with a primary user is studied. Random medium access reporting using unacknowledged transmissions is the case of vehicular networks using IEEE 802.11p. This entails, as opposed to scheduled medium access, a non-negligible probability of collision and a variable reporting phase duration. Sequential reporting can reduce the reporting phase duration by employing different early termination schemes where the Fusion Centre (FC) terminates the reporting process once it receives enough evidence about the primary user status. A reduced reporting phase duration for a given detection accuracy performance enhances the overall network throughput. A centralized CSS scheme, where energy detection is employed at the secondary users, and hard-decision fusion is employed at the FC, is considered in this thesis. The objective is then to derive closed-form expressions for the overall probabilities of detection and false alarm at the FC as well as the average reporting phase duration. Analysis is performed first for the simple OR decision fusion rule, at the FC, and then generalized to the K-out-of-M decision fusion rule. Two early termination schemes are investigated for sequential reporting and then a heuristic energy-based reporting priority scheme is proposed. The proposed energy-based reporting scheme gives higher priority to secondary users more capable of detecting the primary user to access the common reporting channel. The proposed reporting scheme is compared to a base or control scheme where all secondary users have the same reporting priority.
Subjects/Keywords: Cooperative Spectrum Sensing; CR-VANETs; Random Medium Access; Probability of detection; Probability of false alarm
Ahmed, A. M. A. (2020). Random Medium Access Decision-Based Cooperative Spectrum Sensing for Cognitive Radio Vehicular Ad-hoc Networks . (Thesis). University of Ottawa. Retrieved from http://hdl.handle.net/10393/40225
Ahmed, Ahmed Mohamed Abdelsalam. "Random Medium Access Decision-Based Cooperative Spectrum Sensing for Cognitive Radio Vehicular Ad-hoc Networks ." 2020. Thesis, University of Ottawa. Accessed January 21, 2021. http://hdl.handle.net/10393/40225.
Ahmed, Ahmed Mohamed Abdelsalam. "Random Medium Access Decision-Based Cooperative Spectrum Sensing for Cognitive Radio Vehicular Ad-hoc Networks ." 2020. Web. 21 Jan 2021.
Ahmed AMA. Random Medium Access Decision-Based Cooperative Spectrum Sensing for Cognitive Radio Vehicular Ad-hoc Networks . [Internet] [Thesis]. University of Ottawa; 2020. [cited 2021 Jan 21]. Available from: http://hdl.handle.net/10393/40225.
Ahmed AMA. Random Medium Access Decision-Based Cooperative Spectrum Sensing for Cognitive Radio Vehicular Ad-hoc Networks . [Thesis]. University of Ottawa; 2020. Available from: http://hdl.handle.net/10393/40225
20. Gill, Kuldeep S. Cognitive Radio Connectivity for Railway Transportation Networks.
Degree: MS, 2018, Worcester Polytechnic Institute
URL: etd-012218-114509 ; https://digitalcommons.wpi.edu/etd-theses/129
► Reliable wireless networks for high speed trains require a significant amount of data communications for enabling safety features such as train collision avoidance and railway… (more)
▼ Reliable wireless networks for high speed trains require a significant amount of data communications for enabling safety features such as train collision avoidance and railway management. Cognitive radio integrates heterogeneous wireless networks that will be deployed in order to achieve intelligent communications in future railway systems. One of the primary technical challenges in achieving reliable communications for railways is the handling of high mobility environments involving trains, which includes significant Doppler shifts in the transmission as well as severe fading scenarios that makes it difficult to estimate wireless spectrum utilization. This thesis has two primary contributions: (1) The creation of a Heterogeneous Cooperative Spectrum Sensing (CSS) prototype system, and (2) the derivation of a Long Term Evolution for Railways (LTE-R) system performance analysis. The Heterogeneous CSS prototype system was implemented using Software-Defined Radios (SDRs) possessing different radio configurations. Both soft and hard-data fusion schemes were used in order to compare the signal source detection performance in real-time fading scenarios. For future smart railways, one proposed solution for enabling greater connectivity is to access underutilized spectrum as a secondary user via the dynamic spectrum access (DSA) paradigm. Since it will be challenging to obtain an accurate estimate of incumbent users via a single-sensor system within a real-world fading environment, the proposed cooperative spectrum sensing approach is employed instead since it can mitigate the effects of multipath and shadowing by utilizing the spatial and temporal diversity of a multiple radio network. Regarding the LTE-R contribution of this thesis, the performance analysis of high speed trains (HSTs) in tunnel environments would provide valuable insights with respect to the smart railway systems operating in high mobility scenarios in drastically impaired channels. Advisors/Committee Members: Alexander M. Wyglinski, Advisor, Travis Collins, Committee Member, Kaveh Pahlavan, Committee Member.
Subjects/Keywords: Software-defined Radios; LTE-R; Cooperative Spectrum Sensing; Cognitive Radio; Smart Railway Network
Gill, K. S. (2018). Cognitive Radio Connectivity for Railway Transportation Networks . (Thesis). Worcester Polytechnic Institute. Retrieved from etd-012218-114509 ; https://digitalcommons.wpi.edu/etd-theses/129
Gill, Kuldeep S. "Cognitive Radio Connectivity for Railway Transportation Networks." 2018. Thesis, Worcester Polytechnic Institute. Accessed January 21, 2021. etd-012218-114509 ; https://digitalcommons.wpi.edu/etd-theses/129.
Gill, Kuldeep S. "Cognitive Radio Connectivity for Railway Transportation Networks." 2018. Web. 21 Jan 2021.
Gill KS. Cognitive Radio Connectivity for Railway Transportation Networks. [Internet] [Thesis]. Worcester Polytechnic Institute; 2018. [cited 2021 Jan 21]. Available from: etd-012218-114509 ; https://digitalcommons.wpi.edu/etd-theses/129.
Gill KS. Cognitive Radio Connectivity for Railway Transportation Networks. [Thesis]. Worcester Polytechnic Institute; 2018. Available from: etd-012218-114509 ; https://digitalcommons.wpi.edu/etd-theses/129
21. Radhakrishnan, Aravind. Android Phone Controlled Beagle Board Based PSCR in a Dynamic Spectrum Access Environment.
Degree: MS, Electrical and Computer Engineering, 2010, Virginia Tech
► Public Safety Cognitive Radio (PSCR) is a Software Defined Radio(SDR) developed by the Center for Wireless Telecommunications (CWT) at Virginia Tech. PSCR can configure itself… (more)
▼ Public Safety Cognitive Radio (PSCR) is a Software Defined Radio(SDR) developed by the Center for Wireless Telecommunications (CWT) at Virginia Tech. PSCR can configure itself to interoperate with any public safety waveform it finds during the scan procedure. It also offers users the capability to scan/classify both analog and digital waveforms. The current PSCR architecture can only run on a general purpose processor and hence is not deployable to the public safety personnel. In the first part of this thesis an Android based control application for the PSCR on a Beagle Board(BB) and the GUI for the control application are developed. The Beagle Board is a low-cost, fan- less single board computer that unleashes laptop-like performance and expandability. The Android based Nexus One connected to the Beagle Board via USB is used to control the Beagle Board and enable operations like scan, classify, talk, gateway etc. In addition to the features that exist in the current PSCR a new feature that enables interoperation with P25 (CPFSK modulation) protocol based radios is added. In this effort of porting the PSCR to Beagle Board my contributions are the following (i) communication protocol between the Beagle Board and the Nexus One (ii) PSCR control application on the Android based Nexus One (iii) detection/classification of P25 protocol based radios. In the second part of this thesis, a prototype testbed of a Dynamic Spectrum Access (DSA) broker that uses the Beagle Board PSCR based sensor/classifier is developed. DSA in simple terms is a concept that lets the user without license (secondary user) to a particular frequency access that frequency, when the licensed user (primary user) is not using it. In the proposed testbed we have two Beagle Board based sen- sor/classifiers that cooperatively scan the spectrum and report the results to the central DSA broker. The DSA broker then identifies the frequency spectrum with- out primary users and informs the secondary users about the free spectrum. The secondary users can then communicate among each other using the frequency band allocated by the DSA broker. When the primary user enters the spectrum occupied by the secondary user, the DSA broker instructs the secondary user to use a different spectrum. Based on the experiments conducted on the testbed setup in the CWT lab environment, the average time taken by the DSA broker to detect the presence of primary user is 0.636 secs and the average time taken for the secondary user to leave the frequency band that interferes with the primary user is 0.653 secs. Advisors/Committee Members: Bostian, Charles W. (committeechair), Yang, Yaling (committee member), Pratt, Timothy J. (committee member).
Subjects/Keywords: DSA; Cooperative Spectrum Sensing; DSA Broker
Radhakrishnan, A. (2010). Android Phone Controlled Beagle Board Based PSCR in a Dynamic Spectrum Access Environment . (Masters Thesis). Virginia Tech. Retrieved from http://hdl.handle.net/10919/35046
Radhakrishnan, Aravind. "Android Phone Controlled Beagle Board Based PSCR in a Dynamic Spectrum Access Environment." 2010. Masters Thesis, Virginia Tech. Accessed January 21, 2021. http://hdl.handle.net/10919/35046.
Radhakrishnan, Aravind. "Android Phone Controlled Beagle Board Based PSCR in a Dynamic Spectrum Access Environment." 2010. Web. 21 Jan 2021.
Radhakrishnan A. Android Phone Controlled Beagle Board Based PSCR in a Dynamic Spectrum Access Environment. [Internet] [Masters thesis]. Virginia Tech; 2010. [cited 2021 Jan 21]. Available from: http://hdl.handle.net/10919/35046.
Radhakrishnan A. Android Phone Controlled Beagle Board Based PSCR in a Dynamic Spectrum Access Environment. [Masters Thesis]. Virginia Tech; 2010. Available from: http://hdl.handle.net/10919/35046
22. Simpson, Oluyomi. Optimal cooperative spectrum sensing for cognitive radio.
Degree: PhD, 2016, University of Hertfordshire
► The rapid increasing interest in wireless communication has led to the continuous development of wireless devices and technologies. The modern convergence and interoperability of wireless… (more)
▼ The rapid increasing interest in wireless communication has led to the continuous development of wireless devices and technologies. The modern convergence and interoperability of wireless technologies has further increased the amount of services that can be provided, leading to the substantial demand for access to the radio frequency spectrum in an efficient manner. Cognitive radio (CR) an innovative concept of reusing licensed spectrum in an opportunistic manner promises to overcome the evident spectrum underutilization caused by the inflexible spectrum allocation. Spectrum sensing in an unswerving and proficient manner is essential to CR. Cooperation amongst spectrum sensing devices are vital when CR systems are experiencing deep shadowing and in a fading environment. In this thesis, cooperative spectrum sensing (CSS) schemes have been designed to optimize detection performance in an efficient and implementable manner taking into consideration: diversity performance, detection accuracy, low complexity, and reporting channel bandwidth reduction. The thesis first investigates state of the art spectrums sensing algorithms in CR. Comparative analysis and simulation results highlights the different pros, cons and performance criteria of a practical CSS scheme leading to the problem formulation of the thesis. Motivated by the problem of diversity performance in a CR network, the thesis then focuses on designing a novel relay based CSS architecture for CR. A major cooperative transmission protocol with low complexity and overhead - Amplify and Forward (AF) cooperative protocol and an improved double energy detection scheme in a single relay and multiple cognitive relay networks are designed. Simulation results demonstrated that the developed algorithm is capable of reducing the error of missed detection and improving detection probability of a primary user (PU). To improve spectrum sensing reliability while increasing agility, a CSS scheme based on evidence theory is next considered in this thesis. This focuses on a data fusion combination rule. The combination of conflicting evidences from secondary users (SUs) with the classical Dempster Shafter (DS) theory rule may produce counter-intuitive results when combining SUs sensing data leading to poor CSS performance. In order to overcome and minimise the effect of the counter-intuitive results, and to enhance performance of the CSS system, a novel state of the art evidence based decision fusion scheme is developed. The proposed approach is based on the credibility of evidence and a dissociability degree measure of the SUs sensing data evidence. Simulation results illustrate the proposed scheme improves detection performance and reduces error probability when compared to other related evidence based schemes under robust practcial scenarios. Finally, motivated by the need for a low complexity and minmum bandwidth reporting channels which can be significant in high data rate applications, novel CSS quantization schemes are proposed. Quantization methods are considered for a…
Subjects/Keywords: 621.382; Cognitive Radio; Spectrum Sensing; Cooperative Spectrum Sensing; Dynamic Spectrum Access; Data Fusion; Energy Detection; Quantization; Amplify and Forward; Evidence-Based CSS; MLE
Simpson, O. (2016). Optimal cooperative spectrum sensing for cognitive radio . (Doctoral Dissertation). University of Hertfordshire. Retrieved from http://hdl.handle.net/2299/17246
Simpson, Oluyomi. "Optimal cooperative spectrum sensing for cognitive radio." 2016. Doctoral Dissertation, University of Hertfordshire. Accessed January 21, 2021. http://hdl.handle.net/2299/17246.
Simpson, Oluyomi. "Optimal cooperative spectrum sensing for cognitive radio." 2016. Web. 21 Jan 2021.
Simpson O. Optimal cooperative spectrum sensing for cognitive radio. [Internet] [Doctoral dissertation]. University of Hertfordshire; 2016. [cited 2021 Jan 21]. Available from: http://hdl.handle.net/2299/17246.
Simpson O. Optimal cooperative spectrum sensing for cognitive radio. [Doctoral Dissertation]. University of Hertfordshire; 2016. Available from: http://hdl.handle.net/2299/17246
23. Kalyanasundaram, P. (author). Cooperative Spectrum Sensing Algorithms in WBAN.
URL: http://resolver.tudelft.nl/uuid:5227a87b-69d9-4cf9-b43c-5911ca235413
Wireless Body Area Network (WBAN) is used for communication among sensor nodes operating on, in or around the human body in order to monitor vital… (more)
Wireless Body Area Network (WBAN) is used for communication among sensor nodes operating on, in or around the human body in order to monitor vital body parameters and movements. A typical sensor node in WBAN should ensure accurate sensing of the signal from the body, carry out low-level processing of the sensor signal, and wirelessly transmit the processed signal to a local processing unit. One of the main limitations of the WBAN radio receiver at Imec-Holst Centre, is its poor performance in the presence of excessive interference in the unlicensed 2.4 GHz Industrial Scientific and Medical (ISM) band. Several WLAN, bluetooth and Zigbee devices are expected to operate in the same band, causing interference to the WBAN system. The ability to tolerate the presence of unacceptable interference in this band is crucial in order to minimize the energy consumption of the WBAN system. By designing suitable spectrum sensing algorithms using network cooperation, all the available spectral holes (white spaces) in this band can be obtained accurately and efficiently, thereby improving interference tolerance level of the WBAN system. This thesis work focuses on developing energy detection based cooperative spectrum sensing algorithms, that would enhance the interference tolerance capability of WBAN system in the unlicensed 2.4 GHz ISM band. The available spectral holes in this band are expected to be accurately and efficiently obtained by introducing adaptive scheduling techniques in these spectrum sensing algorithms. The challenge lies in designing these algorithms when considering multiple interferer's in the unlicensed 2.4 GHz ISM band, since numerous devices of different applications are expected to be operating in close proximity, using the same band. The proposed algorithms are investigated and compared with respect to various sensing parameters including accuracy, efficiency, energy and complexity.
Advisors/Committee Members: Huang, L. (mentor), Onur, E. (mentor).
Subjects/Keywords: WBAN; Cognitive Radio Network; ISM band; Cooperative Spectrum Sensing; Energy Detection; Multi-Channel Interferers; Sensing Performance; Sequential Sensing; Parallel-Sequential Sensing; Spatial-Temporal Diversity; Hard Decision; Soft Decision; Adaptive Scheduling
Kalyanasundaram, P. (. (2012). Cooperative Spectrum Sensing Algorithms in WBAN . (Masters Thesis). Delft University of Technology. Retrieved from http://resolver.tudelft.nl/uuid:5227a87b-69d9-4cf9-b43c-5911ca235413
Kalyanasundaram, P (author). "Cooperative Spectrum Sensing Algorithms in WBAN." 2012. Masters Thesis, Delft University of Technology. Accessed January 21, 2021. http://resolver.tudelft.nl/uuid:5227a87b-69d9-4cf9-b43c-5911ca235413.
Kalyanasundaram, P (author). "Cooperative Spectrum Sensing Algorithms in WBAN." 2012. Web. 21 Jan 2021.
Kalyanasundaram P(. Cooperative Spectrum Sensing Algorithms in WBAN. [Internet] [Masters thesis]. Delft University of Technology; 2012. [cited 2021 Jan 21]. Available from: http://resolver.tudelft.nl/uuid:5227a87b-69d9-4cf9-b43c-5911ca235413.
Kalyanasundaram P(. Cooperative Spectrum Sensing Algorithms in WBAN. [Masters Thesis]. Delft University of Technology; 2012. Available from: http://resolver.tudelft.nl/uuid:5227a87b-69d9-4cf9-b43c-5911ca235413
24. Jin, Lina. Scheduling, spectrum sensing and cooperation in MU-MIMO broadcast and cognitive radio systems.
URL: https://www.research.manchester.ac.uk/portal/en/theses/scheduling-spectrum-sensing-and-cooperation-in-mumimo-broadcast-and-cognitive-radio-systems(300c7498-c0fb-478a-9f8d-39d005838fb6).html  ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.553542
► In this thesis we investigate how to improve the performance of MU-MIMO wireless system in terms of achieving Shannon capacity limit and efficient use of… (more)
▼ In this thesis we investigate how to improve the performance of MU-MIMO wireless system in terms of achieving Shannon capacity limit and efficient use of precious resource of radio spectrum in wireless communication. First a new suboptimal volume-based scheduling algorithm is presented, which can be applied in MU-MIMO downlink system to transmit signals concurrently to multiple users under the assumption of perfect channel information at transmitter and receiver. The volume-based scheduling algorithm utilises Block Diagonalisation precoding and Householder reduction procedure of QR factorisation. In comparison with capacity-based suboptimal scheduling algorithm, the volume-based algorithm has much reduced computational complexity with only a fraction of sum-rate capacity penalty from the upper bound of system capacity limit. In comparison with semi-orthogonal user selection suboptimal scheduling algorithm, the volume-based scheduling algorithm can be implemented with less computational complexity. Furthermore, the sum-rate capacity achieved via volume-based scheduling algorithm is higher than that achieved by SUS scheduling algorithm in the MIMO case. Then, a two-step scheduling algorithm is proposed, which can be used in the MU-MIMO system and under the assumption that channel state information is known to the receiver, but it is not known to the transmitter and the system under the feedback resource constraint. Assume that low bits codebook and high bits codebook are stored at the transmitter and receiver. The users are selected by using the low bits codebook; subsequently the BD precoding vectors for selected users are designed by employing high bits codebook. The first step of the algorithm can alleviate the load on feedback uplink channel in the MU-MIMO wireless system while the second step can aid precoding design to improve system sum-rate capacity. Next, a MU-MIMO cognitive radio (CR) wireless system has been studied. In such system, a primary wireless network and secondary wireless network coexist and the transmitters and receivers are equipped with multiple antennas. Spectrum sensing methods by which a portion of spectrum can be utilised by a secondary user when the spectrum is detected not in use by a primary user were investigated. A Free Probability Theory (FPT) spectrum sensing method that is a blind spectrum sensing method is proposed. By utilizing the asymptotic behaviour of random matrix based on FPT, the covariance matrix of transmitted signals can be estimated through a large number of observations of the received signals. The method performs better than traditional energy spectrum sensing method. We also consider cooperative spectrum sensing by using the FPT method in MU-MIMO CR system. Cooperative spectrum sensing can improve the performance of signal detection. Furthermore, with the selective cooperative spectrum sensing approach, high probability of detection can be achieved when the system is under false alarm constraint. Finally, spectrum sensing method based on the bispectrum of high-order…
Subjects/Keywords: 621.382; Scheduling; MU-MIMO; Limited feedback; Sum-rate capacity; Cognitive radio; Spectrum sensing; Cooperative spectrum sensing; Higher-order statistics; Free probability theory
Jin, L. (2012). Scheduling, spectrum sensing and cooperation in MU-MIMO broadcast and cognitive radio systems . (Doctoral Dissertation). University of Manchester. Retrieved from https://www.research.manchester.ac.uk/portal/en/theses/scheduling-spectrum-sensing-and-cooperation-in-mumimo-broadcast-and-cognitive-radio-systems(300c7498-c0fb-478a-9f8d-39d005838fb6).html ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.553542
Jin, Lina. "Scheduling, spectrum sensing and cooperation in MU-MIMO broadcast and cognitive radio systems." 2012. Doctoral Dissertation, University of Manchester. Accessed January 21, 2021. https://www.research.manchester.ac.uk/portal/en/theses/scheduling-spectrum-sensing-and-cooperation-in-mumimo-broadcast-and-cognitive-radio-systems(300c7498-c0fb-478a-9f8d-39d005838fb6).html ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.553542.
Jin, Lina. "Scheduling, spectrum sensing and cooperation in MU-MIMO broadcast and cognitive radio systems." 2012. Web. 21 Jan 2021.
Jin L. Scheduling, spectrum sensing and cooperation in MU-MIMO broadcast and cognitive radio systems. [Internet] [Doctoral dissertation]. University of Manchester; 2012. [cited 2021 Jan 21]. Available from: https://www.research.manchester.ac.uk/portal/en/theses/scheduling-spectrum-sensing-and-cooperation-in-mumimo-broadcast-and-cognitive-radio-systems(300c7498-c0fb-478a-9f8d-39d005838fb6).html ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.553542.
Jin L. Scheduling, spectrum sensing and cooperation in MU-MIMO broadcast and cognitive radio systems. [Doctoral Dissertation]. University of Manchester; 2012. Available from: https://www.research.manchester.ac.uk/portal/en/theses/scheduling-spectrum-sensing-and-cooperation-in-mumimo-broadcast-and-cognitive-radio-systems(300c7498-c0fb-478a-9f8d-39d005838fb6).html ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.553542
25. Jackson, David. Exploiting Rogue Signals to Attack Trust-based Cooperative Spectrum Sensing in Cognitive Radio Networks.
Degree: MS, Computer Science, 2013, Virginia Commonwealth University
URL: https://doi.org/10.25772/TDR4-B970  ; https://scholarscompass.vcu.edu/etd/3072
► Cognitive radios are currently presented as the solution to the ever-increasing spectrum shortage problem. However, their increased capabilities over traditional radios introduce a new dimension… (more)
▼ Cognitive radios are currently presented as the solution to the ever-increasing spectrum shortage problem. However, their increased capabilities over traditional radios introduce a new dimension of security threats. Cooperative Spectrum Sensing (CSS) has been proposed as a means to protect cognitive radio networks from the well known security threats: Primary User Emulation (PUE) and Spectrum Sensing Data Falsification (SSDF). I demonstrate a new threat to trust-based CSS protocols, called the Rogue Signal Framing (RSF) intrusion. Rogue signals can be exploited to create the illusion of malicious sensors which leads to the framing of innocent sensors and consequently, their removal from the shared spectrum sensing. Ultimately, with fewer sensors working together, the spectrum sensing is less robust for making correct spectrum access decisions. The simulation experiments illustrate the impact of RSF intrusions which, in severe cases, shows roughly 40% of sensors removed. To mitigate the RSF intrusion's damage to the network's trust, I introduce a new defense based on community detection from analyzing the network's Received Signal Strength (RSS) diversity. Tests show a 95% damage reduction in terms of removed sensors from the shared spectrum sensing, thus retaining the benefits of CSS protocols. Advisors/Committee Members: Wanyu Zang.
Subjects/Keywords: Cognitive Radio; Cooperative Spectrum Sensing; Reputation Scheme; Rogue Signal; Wireless Network Security; Computer Sciences; Physical Sciences and Mathematics
Jackson, D. (2013). Exploiting Rogue Signals to Attack Trust-based Cooperative Spectrum Sensing in Cognitive Radio Networks . (Thesis). Virginia Commonwealth University. Retrieved from https://doi.org/10.25772/TDR4-B970 ; https://scholarscompass.vcu.edu/etd/3072
Jackson, David. "Exploiting Rogue Signals to Attack Trust-based Cooperative Spectrum Sensing in Cognitive Radio Networks." 2013. Thesis, Virginia Commonwealth University. Accessed January 21, 2021. https://doi.org/10.25772/TDR4-B970 ; https://scholarscompass.vcu.edu/etd/3072.
Jackson, David. "Exploiting Rogue Signals to Attack Trust-based Cooperative Spectrum Sensing in Cognitive Radio Networks." 2013. Web. 21 Jan 2021.
Jackson D. Exploiting Rogue Signals to Attack Trust-based Cooperative Spectrum Sensing in Cognitive Radio Networks. [Internet] [Thesis]. Virginia Commonwealth University; 2013. [cited 2021 Jan 21]. Available from: https://doi.org/10.25772/TDR4-B970 ; https://scholarscompass.vcu.edu/etd/3072.
Jackson D. Exploiting Rogue Signals to Attack Trust-based Cooperative Spectrum Sensing in Cognitive Radio Networks. [Thesis]. Virginia Commonwealth University; 2013. Available from: https://doi.org/10.25772/TDR4-B970 ; https://scholarscompass.vcu.edu/etd/3072
26. Tsinos, Christos. Cooperative and cognitive communication techniques for wireless networks.
Degree: 2013, University of Patras; Πανεπιστήμιο Πατρών
► During the past years wireless communications have been exhibiting an increased growth rendering them the most common way for communication. The continuously increasing demand for… (more)
▼ During the past years wireless communications have been exhibiting an increased growth rendering them the most common way for communication. The continuously increasing demand for wireless services resulted in limited availability of the wireless spectrum. To this end, Cognitive Radio (CR) techniques have been proposed in literature during the past years. The concept of CR approach is to utilize advanced radio and signal-processing technology along with novel spectrum allocation policies to enable new unlicensed wireless users to operate in the existing occupied spectrum areas without degrading the performance of the existing licensed ones. Moreover, the broadcast and fading nature of the wireless channel results in severe degradation on the performance of wireless transmissions. A solution to the problem is the use of multiple-antenna systems so as to achieve spatial diversity. However, in many cases, the communicationdevices' nature permit the support of multiple antennas due to size, power consumption, and hardware limitations. To this end, cooperative communications provide an alternative way to achieve spatial diversity via virtual antenna arrays formed by single antenna nodes. It is noteworthy that cooperation has an important role within the CR literature as many techniques developed within its context exploiting the benefits of cooperation in order to achieve improved performance. Therefore, the aim of the present dissertation is to develop efficient and practical cognitive, cooperative and cognitive cooperative schemes. More specifically the contributions are the following ones.The first contribution is a novel CR communication scheme. During the past years numerous CR communication schemes have been presented in literature. To the best of our knowledge, the majority of them were developed assuming perfect Channel State Information (CSI) at the unlicensed user's side. There are several cases where the licensed users do not desire any interaction with the unlicensed ones. In such cases, the assumption that the unlicensed user can obtain CSI that concerns the licensed user channels is not valid and as a result the corresponding communication technique cannot be applied. Therefore, at first we propose an novel CR communication scheme that requires CSI that can be estimated in a completely blind manner. Then, the corresponding blind estimation scheme is developed. Another significant contribution is the theoretical results that have been derived for both the perfect CSI case and the imperfect CSI case (when the blind estimation scheme is employed for obtaining the corresponding CSI). Especially, the theoretical results that concern the imperfect CSI case are some of the first ones that appear in the relevant literature, to the best of our knowledge.The second contribution is a decentralized adaptive Eigenvalue-Based spectrum Sensing (EBSS) technique for multi-antenna CR Systems. Spectrum Sensing is a fundamental functionality in CR systems. In general, the unlicensed user employs a spectrum sensing technique in…
Subjects/Keywords: Συνεργατικές επικοινωνίες; Δίκτυα γνωσιακών κόμβων; Ευθυγράμμιση παρεμβολής; Επισκόπηση φάσματος; Προσανατολισμένη επικοινωνία; Cooperative communications; Cognitive radio; Interference alignment; Spectrum sensing; Beamforming
Tsinos, C. (2013). Cooperative and cognitive communication techniques for wireless networks . (Thesis). University of Patras; Πανεπιστήμιο Πατρών. Retrieved from http://hdl.handle.net/10442/hedi/30093
Tsinos, Christos. "Cooperative and cognitive communication techniques for wireless networks." 2013. Thesis, University of Patras; Πανεπιστήμιο Πατρών. Accessed January 21, 2021. http://hdl.handle.net/10442/hedi/30093.
Tsinos, Christos. "Cooperative and cognitive communication techniques for wireless networks." 2013. Web. 21 Jan 2021.
Tsinos C. Cooperative and cognitive communication techniques for wireless networks. [Internet] [Thesis]. University of Patras; Πανεπιστήμιο Πατρών; 2013. [cited 2021 Jan 21]. Available from: http://hdl.handle.net/10442/hedi/30093.
Tsinos C. Cooperative and cognitive communication techniques for wireless networks. [Thesis]. University of Patras; Πανεπιστήμιο Πατρών; 2013. Available from: http://hdl.handle.net/10442/hedi/30093
27. Su, Hang. Design and Analysis of Opportunistic MAC Protocols for Cognitive Radio Wireless Networks.
Degree: PhD, Computer Engineering, 2012, Texas A&M University
URL: http://hdl.handle.net/1969.1/ETD-TAMU-2010-12-8943
► As more and more wireless applications/services emerge in the market, the already heavily crowded radio spectrum becomes much scarcer. Meanwhile, however,as it is reported in… (more)
▼ As more and more wireless applications/services emerge in the market, the already heavily crowded radio spectrum becomes much scarcer. Meanwhile, however,as it is reported in the recent literature, there is a large amount of radio spectrum that is under-utilized. This motivates the concept of cognitive radio wireless networks that allow the unlicensed secondary-users (SUs) to dynamically use the vacant radio spectrum which is not being used by the licensed primary-users (PUs). In this dissertation, we investigate protocol design for both the synchronous and asynchronous cognitive radio networks with emphasis on the medium access control (MAC) layer. We propose various spectrum sharing schemes, opportunistic packet scheduling schemes, and spectrum sensing schemes in the MAC and physical (PHY) layers for different types of cognitive radio networks, allowing the SUs to opportunistically utilize the licensed spectrum while confining the level of interference to the range the PUs can tolerate. First, we propose the cross-layer based multi-channel MAC protocol, which integrates the cooperative spectrum sensing at PHY layer and the interweave-based spectrum access at MAC layer, for the synchronous cognitive radio networks. Second, we propose the channel-hopping based single-transceiver MAC protocol for the hardware-constrained synchronous cognitive radio networks, under which the SUs can identify and exploit the vacant channels by dynamically switching across the licensed channels with their distinct channel-hopping sequences. Third, we propose the opportunistic multi-channel MAC protocol with the two-threshold sequential spectrum sensing algorithm for asynchronous cognitive radio networks. Fourth, by combining the interweave and underlay spectrum sharing modes, we propose the adaptive spectrum sharing scheme for code division multiple access (CDMA) based cognitive MAC in the uplink communications over the asynchronous cognitive radio networks, where the PUs may have different types of channel usage patterns. Finally, we develop a packet scheduling scheme for the PU MAC protocol in the context of time division multiple access (TDMA)-based cognitive radio wireless networks, which is designed to operate friendly towards the SUs in terms of the vacant-channel probability. We also develop various analytical models, including the Markov chain models, M=GY =1 queuing models, cross-layer optimization models, etc., to rigorously analyze the performance of our proposed MAC protocols in terms of aggregate throughput, access delay, and packet drop rate for both the saturation network case and non-saturation network case. In addition, we conducted extensive simulations to validate our analytical models and evaluate our proposed MAC protocols/schemes. Both the numerical and simulation results show that our proposed MAC protocols/schemes can significantly improve the spectrum utilization efficiency of wireless networks. Advisors/Committee Members: Zhang, Xi (advisor), Reddy, AL Narasimha (committee member), Welch, Jennifer L. (committee member), Loguinov, Dmitri (committee member).
Subjects/Keywords: Cognitive radio; multi-channel MAC; dynamic spectrum access; cross-layer design; M/G^Y/1 queuing theory; QoS provisionings; cooperative spectrum sensing; channel hopping; decision process; rate adaption; opportunistic scheduling
Su, H. (2012). Design and Analysis of Opportunistic MAC Protocols for Cognitive Radio Wireless Networks . (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/ETD-TAMU-2010-12-8943
Su, Hang. "Design and Analysis of Opportunistic MAC Protocols for Cognitive Radio Wireless Networks." 2012. Doctoral Dissertation, Texas A&M University. Accessed January 21, 2021. http://hdl.handle.net/1969.1/ETD-TAMU-2010-12-8943.
Su, Hang. "Design and Analysis of Opportunistic MAC Protocols for Cognitive Radio Wireless Networks." 2012. Web. 21 Jan 2021.
Su H. Design and Analysis of Opportunistic MAC Protocols for Cognitive Radio Wireless Networks. [Internet] [Doctoral dissertation]. Texas A&M University; 2012. [cited 2021 Jan 21]. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2010-12-8943.
Su H. Design and Analysis of Opportunistic MAC Protocols for Cognitive Radio Wireless Networks. [Doctoral Dissertation]. Texas A&M University; 2012. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2010-12-8943
28. Prawatmuang, Warit. Cooperative Spectrum Sensing for Cognitive Radio.
▼ Cognitive Radio (CR) aims to access the wireless spectrum in an opportunistic manner while the licensed user is not using it. To accurately determine the licensed user's existence, spectrum sensing procedure is vital to CR system. Energy detection-based spectrum sensing techniques is favourable due to its simplicity and low complexity. In addition, to improve the detection performance, cooperative spectrum sensing technique exploits multi-user diversity and mitigates detection uncertainty. In this thesis, we investigate several energy detection based cooperative spectrum sensing techniques.First, the closed-form analysis for the Equal Gain Combining based Soft Decision Combining (EGC-SDC) scheme, in which all CR users forward its observation to the fusion center, is derived. In order to reduce the communication overhead between CR users and the fusion center, we proposed quantized cooperative spectrum sensing technique, in which CR users quantize its local observation before forwarding to the fusion center. Next, the Double Threshold scheme, where some users only forward its local decision while other users forward its observation, is considered and analyzed. To further reduce the communication overhead, we also proposed that quantization is applied to the users who forward its observation. Later on, three sequential cooperative spectrum sensing schemes in time-varying channel are considered. By aggregating past local observations from previous sensing slots, CR users can improve the detection performance. The Weighted Sequential Energy Detector (SED) scheme simply takes fixed number of past local observations, while the other two schemes, Two-Stage SED and Differential SED, adaptively determine the number of observations, based on its decision towards primary user's existence.Simulation results show that the analysis on EGC-SDC scheme is accurate and the quantized cooperative spectrum sensing technique can improve the performance and approach the detection performance of EGC-SDC scheme with much less bandwidth requirement. Also, the Double Threshold scheme can help improve the detection performance over the conventional technique. Furthermore, the analysis on Double Threshold provides a closed-form for the probability of false alarm and detection. Additionally, the sequential spectrum sensing schemes are shown to improve the detection performance and enable CR system to work in scenarios that the conventional technique can not accommodate. Advisors/Committee Members: So, Daniel.
Subjects/Keywords: spectrum sensing; cognitive radio; cooperative sensing; energy detection
…6.5 77 77 Quantized Cooperative Spectrum Sensing schemes: Probaility of false alarm and… …Doctor of Philosophy Cooperative Spectrum Sensing for Cognitive Radio September 2, 2013… …detection performance, cooperative spectrum sensing technique exploits multi-user diversity and… …cooperative spectrum sensing techniques. First, the closed-form analysis for the Equal Gain… …forward its observation. Later on, three sequential cooperative spectrum sensing schemes in time…
Prawatmuang, W. (2013). Cooperative Spectrum Sensing for Cognitive Radio . (Doctoral Dissertation). University of Manchester. Retrieved from http://www.manchester.ac.uk/escholar/uk-ac-man-scw:206202
Prawatmuang, Warit. "Cooperative Spectrum Sensing for Cognitive Radio." 2013. Doctoral Dissertation, University of Manchester. Accessed January 21, 2021. http://www.manchester.ac.uk/escholar/uk-ac-man-scw:206202.
Prawatmuang W. Cooperative Spectrum Sensing for Cognitive Radio. [Internet] [Doctoral dissertation]. University of Manchester; 2013. [cited 2021 Jan 21]. Available from: http://www.manchester.ac.uk/escholar/uk-ac-man-scw:206202.
Prawatmuang W. Cooperative Spectrum Sensing for Cognitive Radio. [Doctoral Dissertation]. University of Manchester; 2013. Available from: http://www.manchester.ac.uk/escholar/uk-ac-man-scw:206202
29. ZHENG SHOUKANG. Design of spectrum sensing and mac in cognitive radio networks.
Subjects/Keywords: Cognitive Radio; Spectrum Sensing; Medium Access Control; Bayesian Detector; Cross-Layer; Cooperative Sensing
SHOUKANG, Z. (2011). Design of spectrum sensing and mac in cognitive radio networks . (Thesis). National University of Singapore. Retrieved from http://scholarbank.nus.edu.sg/handle/10635/32470
SHOUKANG, ZHENG. "Design of spectrum sensing and mac in cognitive radio networks." 2011. Thesis, National University of Singapore. Accessed January 21, 2021. http://scholarbank.nus.edu.sg/handle/10635/32470.
SHOUKANG, ZHENG. "Design of spectrum sensing and mac in cognitive radio networks." 2011. Web. 21 Jan 2021.
SHOUKANG Z. Design of spectrum sensing and mac in cognitive radio networks. [Internet] [Thesis]. National University of Singapore; 2011. [cited 2021 Jan 21]. Available from: http://scholarbank.nus.edu.sg/handle/10635/32470.
SHOUKANG Z. Design of spectrum sensing and mac in cognitive radio networks. [Thesis]. National University of Singapore; 2011. Available from: http://scholarbank.nus.edu.sg/handle/10635/32470
30. Τσίνος, Χρήστος. Cooperative and cognitive communication techniques for wireless networks.
▼ During the past years wireless communications have been exhibiting an increased growth rendering them the most common way for communication. The continuously increasing demand for wireless services resulted in limited availability of the wireless spectrum. To this end, Cognitive Radio (CR) techniques have been proposed in literature during the past years. The concept of CR approach is to utilize advanced radio and signal-processing technology along with novel spectrum allocation policies to enable new unlicensed wireless users to operate in the existing occupied spectrum areas without degrading the performance of the existing licensed ones. Moreover, the broadcast and fading nature of the wireless channel results in severe degradation on the performance of wireless transmissions. A solution to the problem is the use of multiple-antenna systems so as to achieve spatial diversity. However, in many cases, the communication devices' nature permit the support of multiple antennas due to size, power consumption, and hardware limitations. To this end, cooperative communications provide an alternative way to achieve spatial diversity via virtual antenna arrays formed by single antenna nodes. It is noteworthy that cooperation has an important role within the CR literature as many techniques developed within its context exploiting the benefits of cooperation in order to achieve improved performance. Therefore, the aim of the present dissertation is to develop efficient and practical cognitive, cooperative and cognitive cooperative schemes. More specifically the contributions are the following ones. The first contribution is a novel CR communication scheme. During the past years numerous CR communication schemes have been presented in literature. To the best of our knowledge, the majority of them were developed assuming perfect Channel State Information (CSI) at the unlicensed user's side. There are several cases where the licensed users do not desire any interaction with the unlicensed ones. In such cases, the assumption that the unlicensed user can obtain CSI that concerns the licensed user channels is not valid and as a result the corresponding communication technique cannot be applied. Therefore, at first we propose an novel CR communication scheme that requires CSI that can be estimated in a completely blind manner. Then, the corresponding blind estimation scheme is developed. Another significant contribution is the theoretical results that have been derived for both the perfect CSI case and the imperfect CSI case (when the blind estimation scheme is employed for obtaining the corresponding CSI). Especially, the theoretical results that concern the imperfect CSI case are some of the first ones that appear in the relevant literature, to the best of our knowledge. The second contribution is a decentralized adaptive Eigenvalue-Based spectrum Sensing (EBSS) technique for multi-antenna CR Systems. Spectrum Sensing is a fundamental functionality in CR systems. In general, the unlicensed user employs a spectrum sensing… Advisors/Committee Members: Μπερμπερίδης, Κωνσταντίνος, Tsinos, Christos, Μπερμπερίδης, Κωνσταντίνος, Θεοδωρίδης, Σέργιος, Ροντογιάννης, Αθανάσιος, Βαρβαρίγος, Εμμανουήλ, Κωτσόπουλος, Σταύρος, Τουμπακάρης, Δημήτριος-Αλέξανδρος, Κρικίδης, Ιωάννης.
Subjects/Keywords: Cooperative communications; Cognitive radio; Interference alignment; Spectrum sensing; Beamforming; 621.382 1; Συνεργατικές επικοινωνίες; Δίκτυα γνωσιακών κόμβων; Ευθυγράμμιση παρεμβολής; Επισκόπηση φάσματος; Προσανατολισμένη επικοινωνία
Τσίνος, �. (2013). Cooperative and cognitive communication techniques for wireless networks . (Doctoral Dissertation). University of Patras. Retrieved from http://hdl.handle.net/10889/7521
Τσίνος, Χρήστος. "Cooperative and cognitive communication techniques for wireless networks." 2013. Doctoral Dissertation, University of Patras. Accessed January 21, 2021. http://hdl.handle.net/10889/7521.
Τσίνος, Χρήστος. "Cooperative and cognitive communication techniques for wireless networks." 2013. Web. 21 Jan 2021.
Τσίνος �. Cooperative and cognitive communication techniques for wireless networks. [Internet] [Doctoral dissertation]. University of Patras; 2013. [cited 2021 Jan 21]. Available from: http://hdl.handle.net/10889/7521.
Τσίνος �. Cooperative and cognitive communication techniques for wireless networks. [Doctoral Dissertation]. University of Patras; 2013. Available from: http://hdl.handle.net/10889/7521