Co-channel interference reduction system for digital high definition television
First Claim
1. For use in a television system having means for processing digitally encoded signals, a co-channel interference reduction system for reducing the amplitude of an interfering co-channel television signal comprising:
- a television transmitter having signal means for producing digitally encoded signals and a precoding filter for performing a first finite field arithmetic process on said digitally encoded signals to produce precoded digitally encoded signals; and
a television receiver having means for processing said precoded digitally encoded signals including a filter having a frequency response selected to reduce interfering co-channel television signals and means coupled to said filter for performing a second finite field arithmetic process upon the output of said filter, said second finite field arithmetic process selected to restore said digitally encoded signal.
9 Assignments
0 Petitions
Accused Products
Abstract
A co-channel interference reduction system for digital high definition television includes a transmitter having a modulo 4 processing precode filter. A receiver includes a pair of selectable video processing modes. The first mode provides a comb filter for removing co-channel interference signals together with a modulo 4 interpreter for restoring the four level data signal despite the intersymbol interference signal introduced by the comb filter segment. In the alternate mode operable in the absence of co-channel interfering signals, a level slicer and postcoder are used to restore the precoded signal to the original four level data signal.
98 Citations
32 Claims
-
1. For use in a television system having means for processing digitally encoded signals, a co-channel interference reduction system for reducing the amplitude of an interfering co-channel television signal comprising:
-
a television transmitter having signal means for producing digitally encoded signals and a precoding filter for performing a first finite field arithmetic process on said digitally encoded signals to produce precoded digitally encoded signals; and a television receiver having means for processing said precoded digitally encoded signals including a filter having a frequency response selected to reduce interfering co-channel television signals and means coupled to said filter for performing a second finite field arithmetic process upon the output of said filter, said second finite field arithmetic process selected to restore said digitally encoded signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
-
-
11. For use in a television system having means for processing digitally encoded signals and for transmitting said processed digitally encoded signals over a selected television channel, a co-channel interference reduction system for reducing the amplitude of an interfering co-channel television signal having a plurality of periodic signal components therein, said co-channel interference reduction system comprising:
-
television transmitter signal means for producing digitally encoded signals and a precoding filter for performing a first finite field arithmetic process on said digitally encoded signals to produce precoded digitally encoded signals; means for transmitting said precoded digitally encoded signals using a carrier signal having a frequency offset from the co-channel interfering signal; and a television receiver having means for receiving and processing said transmitted precoded digitally encoded signals including a receiver filter having a frequency response selected to reduce interfering co-channel television signals and a second finite field processor coupled to said receiver filter performing a second finite field arithmetic process upon the output of said receiver filter, said second finite field arithmetic process selected to restore said digitally encoded signals. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 20)
-
-
21. For use in a television system having means for processing digitally encoded signals, a method of reducing the amplitude of an interfering co-channel television signal having a plurality of periodic signal components therein, said method of reducing the amplitude of co-channel interference signals comprising the steps of:
-
producing digitally encoded television signals; performing a first finite field arithmetic process on said digitally encoded television signals to produce precoded digitally encoded signals; transmitting said precoded digitally encoded signals over a selected television channel; receiving said transmitted precoded digitally encoded signals; and processing said received digitally encoded signals using a filter having a frequency response selected to reduce interfering co-channel television signals and performing a second finite field arithmetic process upon said precoded digitally encoded signals after said step of processing, said second finite field arithmetic process selected to restore said precoded digitally encoded signals to said digitally encoded signal. - View Dependent Claims (22, 23)
-
-
24. For use in a television system processing digitally encoded signals in which a television transmitter includes signal means for producing digitally encoded signals and a precoding filter for performing a first finite field arithmetic process on the digitally encoded signals to produce precoded digitally encoded signals, a television receiver comprising:
means for processing said precoded digitally encoded signals including a filter having a frequency response selected to reduce interfering co-channel television signals and means coupled to said filter for performing a second finite field arithmetic process upon the output of said filter, said second finite field arithmetic process selected to restore said digitally encoded signal. - View Dependent Claims (25)
-
26. For use in a television system having means for processing digitally encoded signals, a co-channel interference reduction system for reducing the amplitude of an interfering co-channel television signal comprising:
-
a television transmitter having signal means for producing digitally encoded signals and a precoding filter for performing a first finite field arithmetic process on said digitally encoded signals to produce precoded digitally encoded signals; a television receiver having means for processing said precoded digitally encoded signals including a filter having a frequency response selected to reduce interfering co-channel television signals and means coupled to said filter for performing a second finite field arithmetic process upon the output of said filter, said second finite field arithmetic process selected to restore said digitally encoded signal; means performing a third finite field arithmetic process upon said precoded digitally encoded signals to complement said first finite field arithmetic process; and switch means for alternatively coupling said digitally encoded signals via either said filter and said means for performing a second finite field arithmetic process or via said means for performing a third finite field arithmetic process.
-
-
27. For use in a television system processing digitally encoded signals in which a television transmitter includes signal means for producing digitally encoded signals and a precoding filter for performing a first finite field arithmetic process on the digitally encoded signals to produce precoded digitally encoded signals, a television receiver comprising:
-
means for processing said precoded digitally encoded signals including a filter having a frequency response selected to reduce interfering co-channel television signals and means coupled to said filter for performing a second finite field arithmetic process upon the output of said filter, said second finite field arithmetic process selected to restore said digitally encoded signal; means performing a third finite field arithmetic process upon said precoded digitally encoded signals to complement said first finite field arithmetic process; and switch means for alternatively coupling said digitally encoded signals via either said filter and said means for performing a second finite field arithmetic process or via said means for performing a third finite field arithmetic process.
-
-
28. A television system having reduced susceptibility to interfering co-channel television signals comprising:
-
a television transmitter having signal means for producing an N level digitally encoded signal and a modulo N precoder for precoding said N level digitally encoded signal to produce an N level precoded digitally encoded signal; and a television receiver comprising a filter having a frequency response selected for reducing interfering co-channel television signals and for producing an M level output signal in response to said N level precoded digitally encoded signal, where M is greater than N, and means for converting said M level output signal to said N level digitally encoded signal. - View Dependent Claims (29, 30)
-
-
31. A television signal receiver having reduced susceptibility to interfering co-channel television signals comprising:
-
means for receiving an N level precoded signal representing an N level digitally encoded video data signal; filter means having a frequency response selected for reducing interfering co-channel television signals and for producing an M level output signal in response to said received precoded signal, where M is greater than N; and means for converting said M level output signal to said N level digitally encoded video data signal. - View Dependent Claims (32)
-
Specification