Multi-hop relay selection based on fade durations

The selection of a relay in a cooperative network is usually based on signal-to-noise ratio (SNR). In a situation where the SNR is low due to Rayleigh fading, the receiver signal may show a sudden loss. Such signal loss may result in significant loss of information at the receiver and it is the duration of such a loss period that will most significantly cause channel and source coding to fail. To avoid such a phenomenon in relay selection, it is important to compute second-order statistics and select relays based on fade duration (FD), both average fade duration (AFD) and the probability that a fade duration will exceed a threshold. This paper provides algorithms for AFD-based and FD threshold-based relay selection in multiple and single hop cooperative wireless networks. It also shows how to increase the reliability of the network by minimizing the average fade duration.