Limited Feedback for Multi-Antenna Multi-user Communications with Generalized Multi-Unitary Decomposition

TL;DR

This paper introduces GMUD, a novel matrix decomposition for multi-user MIMO systems that enables effective precoding with limited feedback by leveraging multiple unitary solutions to mitigate channel information inaccuracies.

Contribution

The paper presents GMUD, a new matrix decomposition method that facilitates multi-user MIMO precoding without full channel state information, improving interference management.

Findings

GMUD provides multiple solutions for unitary matrices P and Q.

The proposed precoding method reduces inter-user interference.

It effectively compensates for limited feedback inaccuracies.

Abstract

In this paper, we propose a decomposition method called Generalized Multi-Unitary Decomposition (GMUD) which is useful in multi-user MIMO precoding. This decomposition transforms a complex matrix H into PRQ, where R is a special matrix whose first row contains only a non-zero user defined value at the left-most position, P and Q are a pair of unitary matrices. The major attraction of our proposed GMUD is we can obtain multiple solutions of P and Q >. With GMUD, we propose a precoding method for a MIMO multi-user system that does not require full channel state information (CSI) at the transmitter. The proposed precoding method uses the multiple unitary matrices property to compensate the inaccurate feedback information as the transmitter can steer the transmission beams of individual users such that the inter-user interference is kept minimum.