Asymptotic Performance Analysis of Packet Cooperative Relaying System over Quasi-Static Fading Channel

Despite the very substantial body of research on the performance analysis of cooperative relay systems, most studies focus on either the symbol error ratio (SER) or outage behavior. This paper analyzes the asymptotic average packet error rate (PER) of the packet cooperative relay system for both AF (Amplify-and-Forward) and DF (Decode-and-Forward) schemes in the high signal-to-noise ratio (SNR) region, and studies the effect of packet length on average PER performance. It is shown that the system achieves the same diversity gain in terms of PER as in terms of SER, but with different coding gain depending on packet length. If we consider practical packet lengths, the DF scheme always achieves better performance than the AF scheme; with shorter packet length, the advantage of DF over AF is more significant. For large enough packet length, AF performance approaches that of DF.