Analysis on Theory of MIMO and Research on Channel Capacity of MIMO System

Abstract By 2023, the average rate of global mobile network will increase to 44Mbps, 5G mobile communication network rate will reach 575Mbps [1]. Compared with 4G mobile communication, 5G mobile communication can support higher quality, higher transmission rate, higher user density and higher mobility performance, as well as lower delay and lower energy consumption scenarios [2]. With the advent of large-scale commercialization of 5G technology, the improvement of transmission performance can meet the growing communication needs of people well, and multiple antenna system (MIMO) has certain superiority in improving channel capacity. This article is aimed at introducing the working principle of MIMO system and the improvement of transmission performance brought by the technologies adopted. Furthermore, the proof of improvement of channel capacity brought by MIMO will be given. A channel model of MIMO communication system will be established through MATLAB, generating channel matrices randomly according to Gaussian distribution and then getting channel capacity by means of calculating the average value of multiple groups of data. The result shows that the channel capacity could improve greatly with the increase of the number of antennas under the condition of the same signal noise ratio (SNR), reaching the conclusion that MIMO system can effectively improve channel capacity.