Research On Multi-antenna Communication Anti-interference Technology Based On Time Reversal

With the advent of the 5G communication era,wireless communication has become more and more popular in people's life,bringing great convenience to people's life.However,along with the rapid spread of smart mobile terminals and the increase of wireless transmission bandwidth,a series of problem appear.On the one hand,with the increase of carrier frequency,signals are constantly reflected,refracted,and scattered by objects in the natural environment during transmission,and propagation loss increased.On the other hand,with the increase of individual mobile users and the dense deployment of antennas,the correlation between transmission channels is presented and the interference between users becomes more and more serious.Due to its unique time focusing and spatial focusing characteristics,time reversal technology can eliminate various interferences in wireless transmission systems and suppress multipath fading in wireless communication systems.This paper mainly focuses on the inter-user interference in millimeter-wave mass MIMO system and the problem of inter-symbol interference and multi-stream interference in UWB wireless transmission systems.Two anti-interference techniques based on time reversal are proposed to reduce the interference of wireless transmission.Interference in the system improves the system's transmission capacity.The main research content of this article includes the following two points:First,in order to solve the problem of inter-user interference in millimeter-wave massive MIMO systems,an Interference elimination time reversal technique is first proposed,which is based on the transmission principle of traditional time reversal signals,and optimizes the solution.This makes the inter-user interference in millimeter wave massive MIMO system close to zero.Then the system performance of the program is analyzed from theory.Simulation results show that the proposed Interference elimination time reversal technology reduces the average bit error rate,greatly improves the system's total reach rate and system's user load capacity.Secondly,in order to solve the problem of inter-symbol interference and multi-stream interference in multi-user UWB systems,two anti-interference equalizers are proposed,namely TR-ZF equalizer and TR-MMSE equalizer.The equalizer exploits the space-time focusing feature of time-reversal and is designed based on a shortened equivalent channel.The anti-interference equalizer and the TR pre-filter are then cascaded for in multi-user UWB system.Simulation experiments show that the cascade of equalizers and TR prefilters can reduce the complexity of UWB system,reduce inter-symbol interference and multi-stream interference in SIMO-UWB systems,and increase system's capacity.