TDMA Achieves the Same Diversity Gain as Opportunistic Scheduling in Relay-Assisted Wireless Networks
Opportunistic scheduling has been recognized as an effective method that significantly outperforms fixed TDMA scheduling in both channel capacity and communication reliability. Nevertheless the superior system performance comes at a price of high computational complexity, large signaling overhead, and unfairness among users. In this paper, the authors find that in relay-assisted next-generation wireless networks, fixed TDMA scheduling achieves the same diversity gain as opportunistic scheduling, as long as the "Best" relay is carefully selected. Moreover, by introducing very limited opportunism, TDMA scheme yields the same optimal outage probability attained by full scale opportunistic scheduling at high SNR.