Research On Signal Detection Algorithms Of Massive MIMO For 5G Mobile Communication System

With the booming development of Mobile Internet, the number of users and the amount of data transmission has been increasing sharply. The service provided by 3G/4G gradually cannot meet the demands of users and research on the 5th generation mobile communications(5G) has already begun. Massive MIMO technology brings huge improvements in spectral efficiency and energy efficiency through the use of a large excess of antennas for base station, which is the core technology of future 5G mobile network. In massive MIMO system, number of BS antennas can be several hundred which lead to the result that complexity of the signal processing at receiver increases greatly. It has become the bottleneck in practical application. In this context,this thesis studies the performance and complexity of different signal detection algorithms used in uplink channel of a massive MIMO system to explore suitable detection algorithms in the large MIMO regime.The thesis firstly reviews characteristics and research status of massive MIMO technology and introduces the system model of massive MIMO. The software simulations and theoretical analysis in the rest of this thesis are based on the system model.In the following, the thesis discusses two categories of signal detection algorithms for massive MIMO, that is linear and non-linear signal detection schemes. The detailed analyses and simulations on complexity, detection performance and improvements in spectral efficiency and energy efficiency of three kinds of linear signal detection algorithms(MRC, ZF, MMSE) are given. Then the thesis simulates and analyzes the performances of three kinds of non-linear signal detection algorithms(ZF-SIC/MMSE-SIC, BI-GDFE, TS) under the massive MIMO system model, and improves the algorithms to satisfy the low-complexity requirement of massive MIMO system. Furthermore, the thesis compares two categories of signal detection algorithms by simulation.Finally, this thesis proposes a low-complexity non-linear signal detection algorithm(MRC-SO-SIC) for massive MIMO system and optimizes the detection ordering. The result of simulation shows that the proposed detection algorithm can achieves the same performance as non-linear signal detection algorithm(ZF-SIC) with a much lower complexity than linear signal detection algorithm(ZF) under the system model of massive MIMO.