On the Capacity of Dual-Hop Multiple Antenna AF Relaying Systems with Feedback Delay and CCI

In this letter, we develop a unified framework for the ergodic capacity of dual-hop multiple antenna amplify-and-forward (AF) relaying systems employing transmit beamforming and maximum ratio combining (TB/MRC) with feedback delay and co-channel interference (CCI). Over Rayleigh fading channels, a new closed-form expression for the exact cumulative distribution function (CDF) of the end-to-end SINR is derived. Based on this, we present the exact expression and the closed-form upper and lower bounds of the ergodic capacity, respectively. The derived analytical results provide an efficient mathematical tool for the fast evaluation of the ergodic capacity of the system as well as for the investigation of the impact of key parameters such as feedback delay, number of antennas and CCI on the ergodic capacity of the system. Monte Carlo simulations are also provided to verify the correctness of the exact results and demonstrate the tightness of the proposed bounds.