On the Optimization of a PSP-Based CPM Detection

Abstract

This paper deals with a reduced-complexity per survivor processing-based CPM demodulation. It relies on a trellis with reduced state number and defined from a rational modulation index possibly different from the transmit modulation index and referred to as virtual receiver modulation index. The virtual receiver modulation index should be chosen so as to achieve a tradeoff between error-rate performance and complexity reduction. The main purpose of this paper is the choice of the virtual receiver modulation index. It gives guidelines to discard the values of the virtual receiver modulation index, that degrade the error-rate performance. Two criteria are used. The first one considers the uncoded CPM case and is based on an approximation of the minimal Euclidean distance. The second one is related to the bit interleaved coded CPM case and resorts to an EXIT chart to analyse the convergence of the iterative receiver. Index terms: continuous phase modulation, EXIT charts, minimum Euclidean distance, per survivor processing, iterative decoding.

Serially Concatenated Schemes for Single Sideband Continuous Phase Modulation

“…It consists of a conventional binary CC, a symbol interleaver, an SSB-FSK modulator, and an iterative decoder able to decode this serially concatenated code [8], [10], [15]. Based on the general definition of the SSB-FSK CPM family, the modulation index is given by h = k/p, where k and p are relatively prime positive integers.…”

Performance vs. Spectral Properties For Single-Sideband Continuous Phase Modulation

“…For |C α | = 1 (integer values of h), (15) is not valid anymore. However, with |C α | = 1 we can set…”