A Practical Scheme for Relaying in Sensor Networks Using Repeat-Accumulate Codes

Given limitations with current technology, nodes in a sensor network have stringent energy and complexity constraints. This paper presents a scheme for cooperation via relaying and error-control coding in sensor networks, using punctured systematic repeat-accumulate codes. Assuming knowledge of the source-relay channel quality, we use density evolution to show that the proposed scheme achieves good performance and a good energy tradeoff despite low computational complexity. An interesting additional benefit of such a scheme is the notion of fractional cooperation by a relay node. As a motivating example, we analyze networks of up to ten cooperating nodes in Rayleigh fading, which communicate with a more sophisticated receiver.