A Comparison of Soft and Hard Coded Relaying (1202.1992v1)

Abstract: "Amplify and Forward" and "Decode and Forward" are the two main relaying functions that have been proposed since the advent of cooperative communication. "\textit{Soft} Decode and Forward" is a recently introduced relaying principle that is to combine the benefits of the classical two relaying algorithms. In this work, we thoroughly investigate \textit{soft} relaying algorithms when convolutional or turbo codes are applied. We study the error performance of two cooperative scenarios employing soft-relaying. A novel approach, the mutual information loss due to data processing, is proposed to analyze the relay-based soft encoder. We also introduce a novel approach to derive the estimated bit error rate and the equivalent channel SNR for the relaying techniques considered in the paper.