Demodulation and decoding of trellis coded continuous phase modulations in an incoherent mobile radio environment

Abstract Digital communication systems using Trellis Coded‐Continuous Phase Modulations (TC‐CPM) have been shown to be power efficient, both for coherent and incoherent detection. In this paper some techniques for the incoherent detection of TC‐CPM signals in a radio‐mobile environment are studied. Two different differential decoding algorithms for the detection of TC‐CPM are presented. The first one is a Viterbi algorithm characterised by a reduced number of states when compared with the classical coherent Viterbi detector. The second one is a modified SAN(B) algorithm for the incoherent detection of convoluttonally encoded CPM over a mobile radio environment. Comparisons with the coherent Viterbi decoder show that the proposed algorithms are quite attractive, especially in the case of frequency non‐selective radiomobile channels.