Research on multi-user paired grouping strategy based on channel correlation in large scale MIMO systems

• 1、School of Electronic Engineering,Beijing University of Posts and Telecommunications,Beijing 100876

Abstract：Massive MIMO technology has been a hot topic in the field of communication. Theoretically, a large number of antennas can be deployed at the base station side to obtain abundant degrees of Freedom, so as to improve the spectrum utilization, energy efficiency and system capacity of the system. However, in practical application scenarios, because the number of antennas deployed at the base station side cannot be infinite, there will be common channel interference between users multiplexing the same simultaneous frequency resources.Therefore, in order to reduce the co-channel interference and make full use of the limited time-frequency resources of the system, an improved adaptive multi-user pairing and grouping strategy is proposed based on spatial channel correlation. Simulation results show that this strategy can effectively reduce the randomness and randomness in the adaptive multi-user pairing grouping strategy, so that the spatial channel correlation between any two users assigned to the same paired user group is below the threshold value (threshold value of channel correlation). The strategy also makes the selected optimal threshold (the threshold when the total system rate reaches the maximum) as low as possible, further reducing the interference between users. Therefore, this strategy effectively reduces the interference between users while improving the system capacity, greatly increases the system throughput, and improves the performance of the system. The effect of the number of paired groups on system performance is also discussed.

Keywords： Massive MIMO spatial channel correlation common channel interference optimal threshold paired grouping