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US 5,777,692 AGranted
Receiver based methods and devices for combating co-channel NTSC interference in digital transmission
AssigneePhilips Electronics North America Corporation
InventorMonisha Ghosh
Life of this patent
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Abstract
A device and method for removing co-channel conventional television signal interference from a digital signal by using an-adaptive filter which tunes to the periodic components of the conventional television signal. The output of the adaptive filter is then subtracted from the received signal to produce an error signal. This error signal is then used to recursively update the taps of the adaptive filter. The invention also relates to the use of the adaptive filter in conjunction with a DFE.
Claims27
A method of removing co-channel interference from a digital signal, comprising the steps of:
- receiving the digital signal which includes a plurality of symbols, noise and co-channel interference;
- delaying the received digital signal;
- adaptively filtering the delayed signal using a feed forward adaptive filter having a plurality of adjustable taps;
- subtracting the adaptively filtered signal from the received digital signal and producing an error signal;
- and
- recursively using the error signal to adjust the taps of the adaptive filter to minimize the mean squared error of the error signal such that the adaptive filter becomes tuned to the co-channel interference.
3 more elements
A filtering system for removing co-channel interference from a digital signal, comprising:
- means for receiving the digital signal which digital signal includes a plurality of symbols, the co-channel interference and noise;
- means for delaying the received digital signal;
- feed forward adaptive filter means for adaptively filtering the delayed signal and including a plurality of adjustable taps;
- means for subtracting the adaptively filtered signal from the received digital signal and for producing an error signal, and
- means for recursively adjusting the taps of the forward adaptive filter means by using the error signal while minimizing the mean squared error of the error signal, such that the forward adaptive filter means becomes tuned to the co-channel interference and produces an estimate of the co-channel interference.
2 more elements
A method of removing co-channel interference from a digital signal, comprising the steps of:
- receiving the digital signal which includes a plurality of symbols, noise and co-channel interference;
- delaying the received digital signal;
- adaptively filtering the delayed signal using a feed forward adaptive filter having a plurality of adjustable taps;
- and
- recursively adjusting the taps of the forward adaptive filter in accordance with an adaptive algorithm such that the forward adaptive filter becomes tuned to the co-channel interference and produces an estimate of the co-channel interference;
- and
- subtracting the estimate of the co-channel interference from the received digital signal.
4 more elements
A filtering system for removing co-channel interference from a digital signal, comprising:
- means for receiving the digital signal which digital signal includes a plurality of symbols, the co-channel interference and noise;
- means for delaying the received digital signal;
- feed forward adaptive filter means including a plurality of adjustable taps for adaptively filtering the delayed signal;
- means for recursively adjusting the taps of the forward adaptive filter means in accordance with an adaptive algorithm such that forward the adaptive filter means becomes tuned to the co-channel interference and produces an estimate of the co-channel interference;
- and
- first subtracting means for subtracting the estimate of the co-channel interference from the received digital signal.
3 more elements
A method of removing co-channel interference from a digital signal, comprising the steps of
- receiving the digital signal which digital signal includes a plurality of symbols, noise and co-channel interference;
- delaying the received digital signal;
- adaptively filtering the delayed signal using a adaptive filter having a plurality of adjustable taps;
- forward filtering the received digital signal using a forward filter with a plurality of adjustable taps;
- subtracting the adaptively filtered signal from the forward filtered signal and producing a first signal;
- quantizing the first signal;
- feedback filtering the quantized signal using a feedback filter with a plurality of adjustable taps;
- subtracting the filtered quantized signal from the first signal and producing an error signal;
- and
- adjusting the adjustable taps of the adaptive filter by using the error signal and an adaptive algorithm such that the adaptive filter becomes tuned to the co-channel interference and produces an estimate of the co-channel interference.
7 more elements
A filtering system for removing co-channel interference from a digital signal, comprising:
- means for receiving the digital signal which digital signal includes a plurality of symbols, noise and co-channel interference;
- means for delaying the received digital signal;
- adaptive filter means having a plurality of adjustable taps for adaptively filtering the delayed signal;
- forward filter means having a plurality of adjustable taps for forward filtering the received digital signal;
- first subtracting means for subtracting the adaptively filtered signal from the forward filtered signal and producing a first signal;
- means for quantizing the first signal;
- feedback filter means having a plurality of adjustable taps for feedback filtering the quantized signal;
- second subtracting means for subtracting the filtered quantized signal from the first signal and producing an error signal;
- and
- adjusting means for adjusting the adjustable taps of the adaptive filter by using the error signal and an adaptive algorithm such that the adaptive filter becomes tuned to the co-channel interference and produces an estimate of the co-channel interference.
7 more elements
A television receiver including a filtering system for removing interference from a digital signal, the filtering system comprising:
- means for receiving the digital signal which digital signal includes a plurality of symbols, the co-channel interference and noise;
- means for delaying the received digital signal;
- feed forward adaptive filter means including a plurality of adjustable taps for adaptively filtering the delayed signal;
- means for recursively adjusting the taps of the forward adaptive filter means in accordance with an adaptive algorithm such that the forward adaptive filter means becomes tuned to the co-channel interference and produces an estimate of the co-channel interference;
- and
- first subtracting means for subtracting the estimate of the co-channel interference from the received digital signal.
3 more elements
A television receiver including a filtering system for removing interference from a digital signal, the filtering system comprising:
- means for receiving the digital signal which digital signal includes a plurality of symbols, the co-channel interference and noise;
- means for delaying the received digital signal;
- feed forward adaptive filter means for adaptively filtering the delayed signal and including a plurality of adjustable taps;
- means for subtracting the adaptively filtered signal from the received digital signal and for producing an error signal;
- and
- means for recursively adjusting the taps of the forward adaptive filter means by using the error signal while minimizing the mean squared error of the error signal, such that the forward adaptive filter means becomes tuned to the co-channel interference and produces an estimate of the co-channel interference.
3 more elements
A television receiver including a filtering system for removing conventional television signal interference from a digital signal the following system comprising:
- means for receiving the digital signal which digital signal includes a plurality of symbols, noise and co-channel conventional television signal interference;
- means for delaying the received digital signal;
- adaptive filter means having a plurality of adjustable taps for adaptively filtering the delayed signal;
- forward filter means having a plurality of adjustable taps for forward filtering the received digital signal;
- first subtracting means for subtracting the adaptively filtered signal from the forward filtered signal and producing a first signal;
- means for quantizing the first signal;
- feedback filter means having a plurality of adjustable taps for feedback filtering the quantized signal;
- second subtracting means for subtracting the quantized signal from the first signal and producing an error signal;
- and
- adjusting means for adjusting the adjustable taps of the adaptive filter by using the error signal and an adaptive algorithm such that the adaptive filter becomes tuned to the co-channel conventional television signal interference and produces an estimate of the co-channel conventional television signal interference.
7 more elements
Dependencies are inferred from the claim text.