Patent ID: 6118495
Filing Date: 2000-09-12
Classification: H04L,H04N,Y10S

Abstract:
An electrical signal received by a television signal receiver, which is of a type for receiving digital television signals and has adaptive channel equalization and ghost cancellation filter circuitry that can be trained responsive to a ghost cancellation reference signal, said electrical signal divided into segments having respective initial synchronizing signal portions, said segments being grouped into fields, most of the segments of each field being available for transmitting television information, with a single segment of each field being reserved for other purposes including transmission of said ghost cancellation reference signal, said electrical signal being improved to include a respective plurality of pseudo-random noise sequences within the first half of said reserved segment of each field, at least one of which respective plurality of pseudo-random noise sequences appears in different polarities in different fields for being included in said ghost cancellation reference signal after being separated from other information in said reserved segment of each field by algebraically combining elements of that segment with corresponding elements of at least one other reserved segment from another field.