Outage analysis of a dual-hop OFDM amplify-and-forward relay system with subcarrier mapping in Rayleigh fading
Wireless cooperative relay is an effcient way in obtaining diversity in distributed manner, and it can also be used as a way in extending the cell coverage in cellular systems. In this paper, assuming receiver channel state information (CSI) only, the ergodic and outage capacity analysis are presented for amplify-and-forward (AF) multiple-input multiple-output(MIMO) relay channels deploying orthogonal space-time block codes (OSTBCs). Under flat Rayleigh fading environment, we derive closed-form analytical expressions for the calculation of the ergodic capacity and outage capacity for both the OSTBC transmission with and without the direct link. Numerical results show that all the derived analytical expressions are very tight and are valid for evaluations of the ergodic and outage capacity under various antenna configurations. The results also show how the number of transmit antennas and receives antennas affect the overall channel capacity under fading channel environments.