Interference elimination and antenna optimization method in multi-cell large-scale MIMO system

Abstract

The invention requests to protect an interference elimination and antenna optimization method in a multi-cell large-scale MIMO system, and provides an interference alignment method combining joint spatial division and multiplexing with antenna selection. A user side design a joint receiving filter matrix, compresses an interference space and overcomes the rapid increasing of the quantity of user terminal antennas along with the increasing of a user quantity; a base station side adopts an antenna selection algorithm with low complexity, and selects an appropriate channel vector, so that the quantity of main characteristic values of a channel covariance matrix and the quantity of the selected antennas meet a certain relationship, and thus the combination of interference alignment and joint spatial division and multiplexing is well achieved. Theoretical analysis and estimation results indicate that by using the interference alignment method combining joint spatial division and multiplexing with antenna selection provided by the invention, the system interference can be eliminated, and when the user quantity is large, the quantity of the antennas required by the base station side and the user side is reduced.

Description

technical field [0001] The invention relates to the field of wireless communication multi-cell massive MIMO system, in particular to multi-cell interference elimination technology. Background technique [0002] Massive MIMO technology can significantly improve the spectral efficiency of the system by deploying large-scale antenna arrays in the base station [Lu L, Li G Y, Swindlehurst A L, et al. An overview of massive MIMO: Benefits and challenges [J]. Selected Topics in Signal Processing ,IEEE Journal of,2014,8(5):742-758.], while in the multi-cell massive MIMO system networking, interference has always been one of the most important factors limiting system performance. The interference alignment technology aligns the interference signals from different transmitters in the finite-dimensional space of the receiver through the preprocessing of the transmitter to compress the space occupied by the interference and ensure that the desired signal space is linearly independent of...

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Problems solved by technology

[0004] Compared with the traditional MIMO system, the number of base station antennas in the massive MIMO system is 1 to 2 orders of magnitude higher. Although the system capacity and energy efficiency are improved, the number of radio frequency (Radio Frequency, RF) links is also increased sharply, which brings The circuit loss will also continue to increase

In addition, the number of antennas at both ends of the transceiver required for interference alignment will increase with the increase in the number of interfering users. The pure interference alignment scheme is difficult to apply to massive MIMO systems. Therefore, further measures need to be taken to reduce the number of antennas required by the system

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