Joint Source-Relay Optimization for Two-Path MIMO AF Relay System

In this paper, we consider the inter-relay interference (IRI) problem in a two-path successive amplify-and-forward (AF) multi-input multi-output (MIMO) relay system. First, a new interference cancellation algorithm employed at the relays is proposed to fully remove the IRI with an arbitrary number of antennas. Second, the transmit beamforming matrix at the source, relays and destination are jointly designed to maximize the capacity under the power constraint. Third, we analyze the relation among duplex-gain, diversity-gain, and the multiplex-gain in the different antennas number and SNR, respectively. Finally, Monte Carlo simulations are also given to verify the good performance of the proposed algorithm.