A Comparative Study of Different Relaying Strategies over One-Way Relay Networks

We derive and compare the analytical outage probabilities of conventional decode-and-forward (DF), adaptive DF (ADF), compress-and-forward (CF), and lossy-forward (LF) relaying protocols over fading channels. A joint decoding is assumed at the destination to exploit the source-relay correlation for retrieving the original information of the source. With DF, only if the information sequence can be decoded with an arbitrary low error probability at the relay, it will be forwarded to the destination. With ADF, the source retransmits the information, if a failure of the transmission happens on the source-relay link. With CF, the relay performs the Wyner-Ziv compression and forwards the compressed version to the destination. With LF, the relay node always forwards decoded information sequence to the destination even if a decoding error is detected. The impact of line-of-sight component in the fading variations for transmission chain is taken into account. It is shown that the outage probability with the LF relaying is smaller than that with CF and DF relaying. ADF is superior to LF in terms of outage performance due to the feedback information.