Symbol synchronizer for software defined communications system signal combiner

Abstract

A symbol synchronizer ( ) is provided for a software-defined communications system ( ). The symbol synchronizer ( ), when integrated into either a pre- or post-detection diversity signal combiner ( ), enables highly accurate signal synchronization with minimal added system complexity. The symbol synchronizer ( ) includes a single complex sliding window matched filter ( ) for filtering an input digital signal with a match filtering function based on predetermined signal transfer function characteristics to average out receiver noise from the signal. A signal delay bank ( ) includes a plurality of delay blocks each for delaying the digital signal filtered by the single matched filter for a predetermined number of samples. A complex correlator ( ) correlates the digital signal filtered by the single complex sliding window matched filter ( ) and delayed by the complex correlator ( ) with a correlator reference signal, and selects an index of a path having a peak correlator value. As a result of such a configuration, the symbol synchronizer ( ) is capable of determining symbol boundaries of channel signals in a multi-channel communications system to enable system signal measurement statistics and demodulated to be more accurately generated.