Quantization of Channel State Information for Detect-and-Forward Relaying Schemes

In this paper, we propose a Detect-and-Forward (DetF) relaying scheme for coded communications over fading channels based on the transmission of partial channel state information from the relay to the destination. In order to assist the detection at the destination, the relay transmits a quantized source-relay signal-to-noise ratio and the quantization criterion is based on the minimization of the estimated symbols transition probabilities at the relay. We show that the overhead necessary to communicate the quantized information between the relay and the destination is negligible for practical transmission rates and fading speeds. The efficiency of the proposed scheme is demonstrated through constrained capacity analysis along with throughput simulations based on practical coding schemes.