Outage and Delay Performance of Generalized Multirelay Cooperation Protocols Over Rayleigh Fading Channels

This paper analyzes the performance of generalized multirelay cooperation (GMRC) protocols, which generalize the conventional single- and multiple-relay cooperative protocols, by allowing the number of relays employed in a cooperative cycle to vary with the instantaneous channel condition. Two variants of GMRC protocols are studied, including the output-detection GMRC (OD-GMRC) based on a decoding result and the output-threshold-test GMRC (OT-GMRC) relying on a threshold test. For both protocols, we derive the average outage probability and the average delay for completing a cooperative cycle, assuming uncoded decode-and-forward (DF) relays with multiple receiving antennas. Through numerical results, we validate the analysis accuracy and identify the ideal operational mode of GMRC under different network configurations.