A Comparison of Soft and Hard Coded Relaying

TL;DR

This paper compares soft and hard relaying methods in cooperative communication, analyzing their error performance and introducing new approaches to evaluate mutual information loss and effective channel quality.

Contribution

It provides a comprehensive analysis of soft relaying algorithms with convolutional and turbo codes, including novel methods for error rate and SNR estimation.

Findings

Soft relaying improves error performance over traditional methods.

New analytical approaches for mutual information loss and effective SNR.

Enhanced understanding of soft relaying in cooperative communication scenarios.

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.