Outage Analysis of Decode-and-Forward Relaying System Allowing Intra-link Errors

In this paper, we investigate the outage probability of decode-and-forward (DF) relaying system allowing intra-link (source-relay link) errors, where all the links between the source, relay and destination nodes suffer from independent block Rayleigh fading. In the system, we assume, even if errors are detected in the information sequence after decoding, the relay node still re-encodes and forwards the data sequence containing errors to the destination. The theoretical backbone of this system concept is that the data sequences sent form the source and relay nodes are highly correlated with each other because they are transmitted from the same source, and the correlation knowledge can be well exploited by the joint decoding at the destination node. We derive the outage probability expression for this system, based on Shannon's lossy source-channel separation and Slepian-Wolf's correlated source coding theorems. Moreover, with this system assumption, it is found that the optimal position of the relay is the midpoint between the source and destination nodes. Results of the simulations are provided to verify the accuracy of the analytical results.