Multi-cell pre-coding method for inhibiting pilot pollution in large-scale distributed antenna system

Abstract

The invention relates to a multi-cell pre-coding method for inhibiting pilot pollution in a large-scale distributed antenna system, and belongs to the technical field of wireless communication. The method comprises the following steps: calculating an estimated value of an uplink channel from one user to one RAU in a central cell according to signals received by antennas on the RAU in the central cell; calculating a covariance matrix of errors in the estimated value of the uplink channel on the RAU in the central cell; calculating estimated values of channel vectors from the user to all RAUs of the central cell; calculating estimated values of channel matrixes from all users to all the RAUs of the central cell; calculating transmitting signal vectors of the central cell by conducting multi-cell pre-coding on data vectors of all the users in the central cell; and performing normalization to obtain actual vectors of signals which are finally transmitted by antennas on all the RAUs in the central cell. Through adoption of the method, the impact of pilot pollution on the downlink pre-coding performance can be effectively inhibited, the system throughput can be improved, and the pre-coding calculation complexity can be greatly reduced.

Description

technical field [0001] The invention belongs to the technical field of wireless communication, and relates to a multi-cell precoding method for suppressing pilot pollution in a large-scale distributed antenna system, in particular to a minimum mean square error multi-cell precoding method based on a conjugate gradient method. Background technique [0002] With the rapid increase in the number of mobile terminals, the development of the Internet of Things, and the increasing types of wireless data services, users' demands for wireless data services continue to pose new challenges to existing mobile communication technologies. As a technology with the potential to meet the spectrum efficiency, energy efficiency and channel capacity requirements of future wireless mobile communications, massive multiple-input multiple-output (hereinafter referred to as MassiveMIMO) technology has attracted widespread attention in academia and industry. [0003] The Massive MIMO technology provi...

AI Technical Summary

Problems solved by technology

The existing multi-cell downlink precoding schemes either assume that the ideal CSI is known, or are aimed at a centralized multi-antenna system, and cannot be directly applied to a large-scale distributed antenna system, and its computational complexity increases sharply with the increase in the number of antennas

Therefore, a low-complexity algorithm that uses the estimated channel to precode the downlink transmission data while minimizing the influence of pilot pollution remains to be studied

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