To meet the demand for wireless data traffic having increased since deployment of 4G communication systems, efforts have been made to develop an improved 5G or pre-5G communication system. Therefore, the 5G or pre-50 communication system is also called a ‘Beyond 4G Network’ or a ‘Post LTE System’.
The 5G communication system is considered to be implemented in higher frequency (mmWave) bands, e.g., 60 GHz bands, so as to accomplish higher data rates. To decrease propagation loss of the radio waves and increase the transmission distance, the beamforming, massive multiple-input multiple-output (MIMO), Full Dimensional MIMO (FD-MIMO), array antenna, an analog beam forming, large scale antenna techniques are discussed in 5G communication systems.
In addition, in 5G communication systems, development for system network improvement is under way based on advanced small cells, cloud Radio Access Networks (RANs), ultra-dense networks, device-to-device (D2D) communication, wireless backhaul, moving network, cooperative communication, Coordinated Multi-Points (CoMP), reception-end interference cancellation and the like.
In the 5G system, Hybrid FSK and QAM Modulation (FQAM) and sliding window superposition coding (SWSC) as an advanced coding modulation (ACM), and filter bank multi carrier (FBMC), non-orthogonal multiple access (NOMA), and sparse code multiple access (SCMA) as an advanced access technology have been developed.
A mobile communication system in the mmWave band may suffer an increase in propagation loss such as path loss and return loss due to the frequency characteristics of the extremely high frequency band. As a result, the reach of the radio waves may be reduced, causing a decrease in the service area or the coverage. On the other hand, the wavelength is very short due to the extremely high frequency, so it is easy to apply beamforming in which a plurality of small antennas are used. For the control of the directivity and interference, which are the propagation characteristics of the mmWave band, the beamforming technology may be used. Using a multi-array antenna, not only a base station but also a terminal may generate a beam having a particular angle and width to communicate with each other.
The main difference with the existing cellular system that uses sector beams may consist in that deafness occurs due to the displacement of the beam. For example, in a case where a base station generates a transmission beam to communicate with a terminal, if the terminal uses an omnidirectional antenna as in the prior art without using beamforming, the terminal may have no problem during reception. However, in a case where the terminal uses beamforming, if a reception beam of the terminal does not match a transmission beam of the base station, the antenna gain may significantly fall, so the communication may be almost impossible. On the contrary, even in a case where the terminal generates a transmission beam, similarly, if a reception beam of the base station does not match a transmission beam of the terminal, the communication may be difficult.
The above information is presented as background information only to assist with an understanding of the present disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the present disclosure.