Coherent detection of interleaved trellis encoded CPFSK on shadowed mobile satellite channels

A receiver that utilizes trellis coded continuous phase frequency shift keying (CPFSK) with coherent detection and convolutional interleaving of the coded symbols is presented. A novel decoding algorithm that copes with the interleaving and uses both the modulation trellis and the code trellis is presented. The performance results are obtained by Monte Carlo simulation and are partially verified through analysis. The fading model is Ricean, but the line-of-sight component is subjected to a log-normal transformation that represents attenuations due to foliage (referred to as shadowing). The main application for the receiver is in data transmission, which requires a low bit error rate and has no delay constraints