Exact ergodic capacity of MIMO OSTBC amplify-and-forward relay network with antenna correlation

Abstract

Antenna correlation is usually viewed as a detrimental effect in a multiple input multiple output (MIMO) system. This paper investigates how this affects the performance of an amplify-and-forward (AF) relay network. We consider multiple antennas at all nodes with a general correlation matrix structure having an arbitrary eigenvalue distribution. We derive exact closed form expression for the ergodic capacity and simplify to special case of distinct eigenvalues. Further, we investigate the system in high signal-to-noise ratio (SNR) and derive a simple asymptotic expression. Our results provide a comprehensive analysis and useful insight about the ergodic capacity of the system.