Synchronization signal detection and phase estimation apparatus and

Abstract

A digital television (DTV) receiver receives a data signal that is divided into a plurality of segments each separated by a known data segment sync sequence. The receiver includes a data segment sync signal detector that receives the data signal and filters the signal to provide a filtered data signal. The detector computes the difference between samples of the filtered data signal and an average expected filtered signal value that is representative of a nominal filtered signal value in the middle of the segment sync sequence. The detector then computes the absolute value of the computed difference, and the resultant absolute value is summed with a sampled value from the previous segment and the summed value is stored into an accumulator. The process is repeated for several segments. The location of the data segment sync sequence within the segment is determined by comparing the summed values to determine the smallest summed value, which represents the center of the segment sync sequence. Filtering the data signal with a filter provides a filtered data signal that facilitates accurate detection of the data segment sync sequence and computation of an initial estimate of the sampling phase.