Blind joint detection of cochannel CPFSK signals over Rayleigh flat-fading channels with a diversity antenna array

We describe a new method for blind joint detection of cochannel continuous-phase FSK signals over Rayleigh fading channels. By approximating the time variation (TV) of the temporally over-sampled channel as piecewise linear over appropriately selected detector windows, and by exploiting the finite alphabet property (FA) of the signals, the block-based blind joint detection of cochannel CPFSK (BJDFSK) algorithm estimates all cochannel signals and channels simultaneously. We study signal detectability and show that with a diversity antenna array of arbitrary number of elements, signals can be detected to within an equivalence set. Moreover, an efficient Viterbi-based implementation is presented, and its performance is demonstrated through simulation.