An improved matched filter based symbol synchronizer for MSK transmission over fading multipath channels

We propose a symbol synchronization scheme based on matched filtering and tentative decisions made by the cascaded MLSE detector. Fine estimation of the timing delay is achieved by interpolation and iterative maximum search. The tracking performance of the synchronizer is evaluated by comparing the timing values obtained by the algorithm to two possible timing phase criteria, namely, the Mazo criterion and the minimum squared ISI (msISI) criterion. The timing recovery scheme tracks the variations of the channel almost identically as predicted by the msISI criterion and eliminates the cycle slips successfully. Simulations with MSK transmission have revealed that the method is robust to fast time variations in multipath fading channels, even in moderate signal-to-noise ratios.