A parallel blind demodulator in the presence of intersymbol interference

This paper proposes a demodulator employing data detectors which do not need a known sequence for its startup, i.e., a parallel blind demodulator, in the presence of intersymbol interference (ISI). This demodulator operates as follows: 1) it includes multiple adaptive maximum-likelihood sequence estimations with per-survivor processing (PSP-MLSEs) respectively for different estimated channel memory lengths and different sampling timing thanks to over-sampling; 2) it selects the most reliable PSP-MLSE sequence according to their reliability information. Thus, it uses the known sequence not for data detection and timing/parameter estimation but for the frame synchronization. Finally, computer simulations confirm that performance of this parallel blind demodulator is similar to that of the demodulator with the perfect timing/parameter information in the presence of ISI.