Research On Key Generation Of Physical Layer Based On Full Duplex Technology

Wireless communication is more vulnerable to attack because of openness, which makes many researchers immerse in the research about wireless communication security. One of these researches is key generation mechanism based on short-term reciprocity, spatial variability and time-varying of wireless channel. The key generation is accomplished through the process of selection random common source, the quantization of wireless channel and the key negotiation. However, the current key generation mechanism is inconsistent with the key generation rate and key mismatch rate, and half-duplex mode makes the channel coefficient reciprocity is low, resulting in the key generation rate is generally low. In this paper, we use the characteristics of full-duplex transceiver to improve the reciprocity of the channel and simplify the key extraction process, so as to improve the key generation efficiency and solve the problem of low key generation rate.In this paper, we study the effects of the full duplex communication technology on the key generation mechanism. The main works are as follows: Firstly, the effect of full-duplex relay nodes on the key generation rate is studied on the basis of incomplete self-interference cancellation.Secondly, the effect of multiple full-duplex relays on key generation rate is studied, which is based on the technique of complete self-interference cancellation.In this paper, we first design the communication model in the above two cases, and propose the minimum time slot in the key generation process(the key process can be completed in two time slots). In the key generation process of a single full-duplex relay node, the influence of self-interference on key generation is studied and compared with traditional half-duplex relay nodes. In the case of self-interference is very weak,the key rate can be increased by 50%, and because of the impact of self-interference resulting in the upper bound of the key rate. In the communication model of multi-relay with chain topology, key rate of the model is studied while the SI is prefect eliminate. With the increase of the number of full-duplex relay nodes, the key rate increases exponentially. Besides, the optimal power allocation is given to the nodes by optimization theory in this paper, and the key rate with optimal power allocation is improved compared with the equal power allocation.