MIMO relaying with interference via the CMGF transform

In this paper, we analyze the ergodic capacity of a two-hop multiple-antenna amplify and forward (AF) system, where the relay is subject to co-channel interference (CCI) while the destination is corrupted by additive white Gaussian noise (AWGN) only. A novel integral transform, called the complementary moment generating function transform (CMGF), is proposed as a unified tool to compute the ergodic capacity. When both the relay and destination perform maximum ratio combining (MRC), we derive a new analytical exact expression for the ergodic capacity. It is shown that the ergodic capacity is better improved by increasing the number of antennas at the relay Nr than that at destination Nd. Unfortunately, the system shows an incapability of canceling interference even if Nr and/or Nd grows large.