Symbol Error Probability and Channel Capacity for Multiuser Diversity of Amplify-and-Forward Cooperative Networks

Cooperative diversity can effectively mitigate the effect of fading channel in wireless networks, and multi-user diversity can be exploited by scheduling a user whose channel gain is near the peak. In this paper, a comprehensive study regarding the multi-user diversity of AF cooperative networks is performed. New closed-form expressions for the average symbol error probability for PSK signals and channel capacity are derived. To do this, we also obtain expressions for PDF, CDF, and MGF of the end-to-end SNR at the destination for the best selected user. Simulations show that a multi-user diversity order equals to 2K can still be exploited in AF cooperative networks and the gap of channel capacity between multi-user diversity scheme and single-user cooperative diversity increases as increasing the number of users K .