Transceiver optimization for interference MIMO relay systems using the structure of relay matrix

Abstract

In this paper, we study the transceiver design problem for amplify-and-forward interference multiple-input multiple-output (MIMO) relay communication systems, where multiple transmitter-receiver pairs communicate simultaneously with the aid of a relay node. We aim at minimizing the mean-squared error (MSE) of the signal waveform estimation at the receivers subjecting to transmission power constraints at the transmitters and the relay node. Since the transceiver optimization problem is nonconvex with matrix variables, the globally optimal solution is intractable to obtain. To overcome the challenge, we propose an iterative transceiver design algorithm where the transmitter, relay, and receiver matrices are optimized iteratively by exploiting the optimal structure of the relay precoding matrix. Simulation results show that the proposed algorithm performs better than the existing technique in terms of both MSE and bit-error-rate.

Transceiver Optimization for Multiuser Multiple-Input Multiple-Output Full-Duplex Amplify-and-Forward Relay Downlink Communications

“…AWGN vector with a zero mean and unit variance. As in [6,7,12], channel state information (CSI) is assumed to be available at all nodes. In addition, channel variations during the transceiver matrix update interval are assumed to be relatively small [19] and so do not influence the transceiver design [12].…”

“…The relay node can employ either the decode-and-forward (DF) or amplify-and-forward (AF) protocols. AF amplifies the received signal and forwards it to the destination, so it has a lower complexity than the DF protocol [7].…”

“…In the past decade, full-duplex (FD) relay systems have attracted attention because data transmission from a source to a destination can be completed in one time slot [7][8][9][10][11]. Thus, FD MIMO relaying can increase capacity compared to HD systems [9], but loop interference (LI) is a critical issue because the relay transmits and receives simultaneously.…”