A General Robust Linear Transceiver Design for Multi-Hop Amplify-and-Forward MIMO Relaying Systems

TL;DR

This paper develops a unified, robust transceiver design framework for multi-hop AF MIMO relaying systems with channel estimation errors, improving performance across various design criteria through an optimal structure and iterative algorithms.

Contribution

It introduces a general robust design algorithm that unifies multiple transceiver criteria and derives optimal structures using majorization theory, simplifying complex problems.

Findings

Proposed design outperforms existing algorithms in simulations.

Unified framework covers multiple transceiver design criteria.

Optimal transceiver structure simplifies the design process.

Abstract

In this paper, linear transceiver design for multi-hop amplify-and-forward (AF) multiple-input multiple-out (MIMO) relaying systems with Gaussian distributed channel estimation errors is investigated. Commonly used transceiver design criteria including weighted mean-square-error (MSE) minimization, capacity maximization, worst-MSE/MAX-MSE minimization and weighted sum-rate maximization, are considered and unified into a single matrix-variate optimization problem. A general robust design algorithm is proposed to solve the unified problem. Specifically, by exploiting majorization theory and properties of matrix-variate functions, the optimal structure of the robust transceiver is derived when either the covariance matrix of channel estimation errors seen from the transmitter side or the corresponding covariance matrix seen from the receiver side is proportional to an identity matrix. Based on the optimal structure, the original transceiver design problems are reduced to much simpler problems with only scalar variables whose solutions are readily obtained by iterative water-filling algorithm. A number of existing transceiver design algorithms are found to be special cases of the proposed solution. The differences between our work and the existing related work are also discussed in detail. The performance advantages of the proposed robust designs are demonstrated by simulation results.