On the Performance of Time-Orthogonal Incremental Relaying Based on Demodulate-and-Forward With Distributed Channel Access

This paper considers demodulate-and-forward (DmF)-based incremental relaying (IR) in a distributed setting, where each relay locally makes the decision on cooperation to eliminate network-wide coordination. Unlike traditional IR schemes that use destination feedback merely to activate relays for cooperation, the considered schemes include quantized channel state information (CSI) in destination feedback to facilitate local relay decision. Moreover, two timer-based backoff schemes are employed as the distributed relay selection method. Important performance metrics, including outage probability and average duration to complete a transmission cycle, are derived in closed form for flat Rayleigh fading channels. Comparisons with the well-known distributed relaying schemes are conducted. Numerical results demonstrate that DmF-based IR with quantized feedback serves as a promising solution for low-complexity power-limited wireless networks.