Design of Secure Pilot Spectrum for 5G Oriented Massive MIMO System

In a Massive MIMO system, the base station needs to estimate the channel according to the received pilot signal and obtain the channel state information to design the downlink precoding matrix. The spectrum pattern of pilot signal plays an important role in channel estimation. In this paper, a pilot spectrum based on channel quality is designed. The simulation results show that the performance of the proposed pilot pattern has been effectively improved compared with the traditional pilot pattern. In view of the security problems in the signal transmission process, this paper introduces a symmetric encryption algorithm, and adds a key in the encoding stage of the analog-to-digital conversion part, which effectively improves the security performance of the system.