Noncoherently detected trellis-coded partial response CPM on mobile radio channels

A noncoherent receiver is proposed for partial response trellis-coded continuous phase modulation (TC-CPM) on interleaved flat Rician-fading channels. By using a multiple-symbol observation interval and a simple metric calculator, the power efficiency is improved over a receiver that uses a single-symbol observation interval. Performance bounds on the bit error probability are derived by defining a set of characteristic distances for CPM signals, and showing that TC-CPM is equivalent to a TCM scheme. Our results show that, with the same observation length, the proposed receiver is less than 0.5 dB inferior to a coherent receiver for which perfect channel information is needed. We also conclude that in terms of joint power-bandwidth complexity, 2RC is the best candidate for rate-1/2 TCM codes.