Iterative map and Apri-SOVA receivers for the frequency-selective Rayleigh fading channel

Abstract

Two receivers, an iterative MAP receiver and an iterative Apri-SOVA receiver have been developed for joint demodulation and decoding of signals transmitted over the frequency selective Rayleigh fading channel. The proposed receivers are two stage suboptimal receivers and can detect coded signals with interleaving. Also because the soft-input, soft-output MAP and SOVA algorithms are used, there is no information lost between the stages. When the iterative processing technique is applied, the whole receiver's performance is close to optimal. The error performance of the iterative receivers for the frequency selective Rayleigh fading channel have been studied with computer simulation. The results indicate that significant gain can be obtained with the first iteration. Compared to the MAP receiver, the Apri-SOVA receiver is simpler in its structure and computation, moreover a large size interleaver can be used with it without increasing the computation complexity. This makes the Apri-SOVA receiver more attractive i a practical application.