DTV signals transmitted over the air with a symbol rate of around 10.76
million samples per second include echo-cancellation reference (ECR)
signals each of which includes or essentially consists of a
repetitive-PN1023 sequence with baud-rate symbols, which repetitive-PN1023
sequence incorporates a number of consecutive data-segment synchronization
signals. Receivers for these DTV signals respond to these ECR signals to
generate initial weighting coefficients for adaptive filters used for
channel equalization and echo suppression. The initial weighting
coefficients are calculated from a cepstrum extracted from the
repetitive-PN1023 sequence ECR signal by DFT methods or with a PN1023
auto-correlation match filter.
