Method and apparatus for detecting co-channel interference and selectively filtering the interference when detected

An high definition television for receiving and decoding a vestigial sideband (VSB) comprising:

• a tuner for selecting a VSB signal from a plurality of VSB signals;
• a co-channel interference rejection filter for suppressing a co-channel interference signal within a channel with the selected VSB signal;
• a multiplexer for selectively inserting or removing the co-channel interference filter from a signal path for the selected VSB signal;
• signal processing circuits for equalizing and decoding the selected VSB signal;
• a error detecting circuit for identifying decoding errors produced by the signal processing circuits while decoding the selected VSB signal;
• an error counting circuit for counting the number of errors detected by said error detecting circuit to determine a first error rate and a second error rate, where said first error rate is determined when a co-channel interference filter is not in the signal path and said second error rate is determined when a co-channel interference filter is in the signal path;
• and
• a comparator for comparing the first error rate to the second error rate to determine whether the co-channel interference filter is to subsequently be used or not in the signal path, where the comparator controls the multiplexer.

A method for determining whether a co-channel interference filter should be used in a signal receiver comprising the steps of:

• measuring a first error rate without the co-channel interference filter in a signal path of the signal receiver;
• measuring a second error rate with the co-channel interference filter in the signal path of the signal receiver;
• comparing the first error rate to the second error rate;
• and
• if the first error rate is greater than the second error rate, placing the co-channel interference filter in the signal path of the signal receiver, otherwise, not using the co-channel interference filter.

A digital storage medium containing a program that, when executed by a computer, causes the computer to perform a method comprising the steps of:

• measuring a first error rate without a co-channel interference filter in a signal path of a signal receiver;
• measuring a second error rate with the co-channel interference filter in the signal path of the signal receiver;
• comparing the first error rate to the second error rate;
• and
• if the first error rate is greater than the second error rate, placing the co-channel interference filter in the signal path of the signal receiver, otherwise, not using the co-channel interference filter.