A comparison of soft-coded and hard-coded relaying

作者：Molu Mehdi M^*; Goertz Norbert

来源：European Transactions on Telecommunications, 2014, 25(3): 308-319.

DOI：10.1002/ett.2562

Amplify and forward' and decode and forward' are two main relaying functions that have been proposed since the advent of cooperative communications. Soft decode and forward' is a recently introduced relaying principle that employs a soft-input, soft-output (SISO) Bahl-Cocke-Jelinek-Raviv (BCJR) encoder in the relay; the intention is to combine the benefits of the classical two relaying algorithms. To compare the performance of a SISO BCJR encoder with a conventional hard convolutional encoder, we establish a suitable framework of two cooperative scenarios employing soft and hard coding in the relay. A novel approach, the mutual information loss due to data processing, is proposed for analysis. We also introduce a new approach to estimate the bit error rate and the equivalent channel signal-to-noise ratio for the relaying techniques considered in the paper, involving both the hard and soft encoders. The results reveal new aspects of soft/hard encoding, and we discuss the usefulness of SISO BCJR encoding compared with conventional hard encoding.

• 出版日期2014-3