Joint precoding method for multi-user MIMO relay system including direct transmission link

Abstract

A joint precoding method for a multi-user MIMO relay system including a direct transmission link is disclosed. In the scene of transmitting / receiving end multi-user MIMO relay communication, with MSMSE as a design criterion, the invention provides a joint precoding method with the centralized optimization of all users of a transmitting end. According to the MMSE receiving filter theory, the optimal expression of a receiving filter matrix is directly solved. The sub-optimization problem of a sub-precoding matrix of a transmitting end user is obtained by solving a K.K.T condition, the sub-optimization problem of a relay transceiver matrix is transformed into a standard SDP problem for optimization. Finally, the sub-precoding matrix of the transmitting end user, the relay transceiver matrix and the receiving filter matrix are jointly iterated to convergence, and an optimized precoding matrix is obtained. A simulation analysis verifies that a mean square error and bit error rate performance of the proposed method are good, and the system performance is optimal especially in the case of a low signal-to-noise ratio.

Description

technical field [0001] The invention relates to a joint precoding method, in particular to a joint precoding method of a multi-user MIMO relay system including a direct transmission link, and belongs to the technical field of wireless relay communication. Background technique [0002] In recent years, the development of wireless communication technology has followed the pace of the information age, and new wireless communication technologies have emerged one after another. Today's wireless communication technology is more urgently required to have large capacity, high spectrum utilization, high transmission rate and high reliability. Features. In order to solve these requirements, the relay-assisted multiple-input-multiple-output (MIMO) technology is adopted, and the relay node is considered in the original wireless communication system, forming a "source-relay-sink" A typical three-node communication system structure, this technology can effectively use the space resources...

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Problems solved by technology

For this reason, the present invention aims at the problem that the existing joint precoding method ignores the direct transmission link between multiple users and causes the communication performance to degrade, and takes the minimum sum mean square error (Minimum Sum Mean Square Error, MSMSE) as the design criterion, A joint precoding method for centralized optimization of all users at the transmitter is proposed

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