Effect of CCI and feedback delay on the multi-antenna AF relaying over asymmetric fading channels

This paper investigates the performance of dualhop multiple antenna amplify-and-forward relaying system of transmit beamforming (TB) and maximum ratio combining considering feedback delay and co-channel interference (CCI) at the relay node. Source-relay and relay-destination channels experience Rayleigh and Rician fading respectively. TB vector is calculated using outdated channel state information due to the feedback delay from relay-to-source, and the relay node experience CCI due to frequency reuse in the cellular network. We derive new closed form expressions for the exact cumulative distribution function of the end-to-end signal-to-interference-plus-noise ratio to statistically characterized the system. We also derive closed form expression for the outage probability, bit error rate and ergodic capacity. The system performance is investigated using the derived performance metrics to analyze the effect of Rician fading, CCI, feedback delay and number of antennas.