Noncoherent sequence detection in frequency nonselective slowlyfading channels

A new class of noncoherent sequence detection (NSD) algorithms for combined demodulation and decoding of any coded linear and continuous phase modulations, transmitted over additive white Gaussian noise (AWGN) channels, has been previously presented. In this paper, this class is generalized to the case of frequency nonselective Rayleigh or Rice slowly fading channels, in the presence or absence of channel state information. Coded linear modulations, namely M-ary phase shift keying (M-PSK) and quadrature amplitude modulation (M-QAM), are considered. The proposed detection schemes have a performance which approaches that of coherent detectors, are very robust to phase and frequency instabilities, and compare favorably to other solutions previously proposed in the technical literature