Research On Channel And Interference Estimation Of New Generation Wireless Communication System

Massive MIMO is one of key technology of the new generation wireless communication system.Although it is developed on the basis of traditional MIMO,but its capability and performance have improved substantially.Channel estimation is the basis of signal detection,equalization,precoding and beamforming.At the same time,interference existing in the system affects the performance of the whole communication system.Therefore,this thesis combines massive MIMO technology to study channel estimation and interference estimation in communication system.The main research contents of this thesis include the following aspects:1.This thesis studies the knowledge of massive MIMO technology,channel estimation methods and the interference in the system.The system capacity is analyzed which combined with the access mode of massive MIMO,the advantages and disadvantages of various channel estimation methods and interference estimation methods are compared.2.The channel estimation algorithm based on auxiliary data iteration is extended.The idea of iteration is applied to channel estimation to improve the accuracy of channel estimation,which can reduce the impact of pilot pollution and noise on channel estimation to a certain extent.The simulation results show that the accuracy of channel estimation is related to the correctness of auxiliary data detection,and the estimation effect is better when the signal-to-noise ratio is high.The simulation results show that the accuracy of channel estimation is related to the correctness of auxiliary data detection,and the estimation effect is better when the signal-to-noise ratio is high.Finally,part of the calculation in the algorithm is simplified,and the influence of the simplified algorithm on the accuracy of channel estimation is analyzed and simulated.3.Single cell multi-user interference estimation of downlink in massive MIMO system is studied.Firstly,the interference of downlink is analyzed when appling statistical information to detection.Then,in the fact of the detection interference in the system,a detection method based on downlink pilot is proposed.In this method,the number of pilots is independent of the number of base station antennas but proportional to the number of users,and the pilot overhead is relatively small.Finally,combining MRT precoding with ZF precoding,the ability of this detection method to reduce interference is analyzed.4.Multi-cell multi-user interference estimation of uplink in massive MIMO system is studied.When the number of users and the number of base station antennas tend to be infinite at the same time and the ratio is fixed,the interference of the uplink is estimated.Pilot interference and co-channel user interference in MF detection and MMSE detection are compared.The relationship between pilot interference and large-scale fading,and the relationship between co-channel interference and ? are all studied.Finally,theoretical analysis and simulation are carried out.