Compressive channel sensing based on random pilot for physical layer communication security

Accurate channel state information (CSI) is necessary for correctly receiving information. Compressive sensing has been used for channel estimation because of the sparsity of the wireless multipath channel. Based on compressive sensing, the channel estimation performance by setting pilots randomly is much better than uniformly and successively. This paper proposed a scheme for security communication in physical layer by exploiting the randomness of pilots to prevent eavesdropping in wireless communication. The transmitter places the pilots according to the random pilot codebook, then the legitimate user can accurately estimate CSI according to the codebook and the eavesdropper cannot because of not knowing the position of pilots. The simulation results show that the legitimate user can correctly decode information, while the BER performance of eavesdropper is very bad, and the security capacity is close to the legitimate user´s capacity. This scheme effectively ensures the safety of the physical layer communication.