With development of mobile communication, transmission load of cellular network has greatly increased. In order to relieve spectrum resource scarcity, heterogeneous cellular network has been proposed. In heterogeneous cellular networks, D2D users share frequency resource with cellular users, which improves frequency efficiency effectively. However, serious security problem may be incurred since cellular users are able to overhear information from D2D users underlying in cellular communication links. This paper focuses on improving the secrecy capacity of D2D users in a heterogeneous cellular network by designing adaptive power control and access control schemes. Specifically, we firstly determined a basic security area in which cellular users can be regarded as eligible access objects for D2D users. Then the optimal expression of D2D transmitting power is determined when D2D users share resource with a cellular user located in the basic security area. Finally, we selected a cellular user for D2D pair to access according to the level of information confidentiality. When there's high level of information confidentiality, the Simulated Annealing Algorithm was performed to find a cellular user in order to improve security capacity as much as possible. When D2D pairs communicated normal information, the access object was randomly selected from all cellular users located in basic safety area.
['Xiguang Zhang', 'Yong Shang', 'Shiwei Yan', 'Dehuai Li', 'Junqi Guo']
Adaptive power and access control for physical security of heterogeneous cellular network