Multiple frequency adaptive noise filter for removing interference signals from a frequency band having a desired signal
Patent 4673982 Issued on June 16, 1987. Estimated Expiration Date: 
October 4, 2004. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
October 4, 2004. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent ReferencesSampling arrangement for a television ghost signal cancellation system Ghost canceling apparatus Patent #: 4502077 InventorsAssigneeApplicationNo. 06/657525 filed on 10/04/1984US Classes:348/607, Noise or undesired signal reduction348/608, Processing at encoder or transmitter (e.g., pre-correction)455/295Modulation distortion or cross talk correction or eliminationExaminersPrimary: Chin, Tommy P.Attorney, Agent or FirmInternational ClassesH03H 21/00 (20060101)H04N 5/21 (20060101) AbstractA multiple frequency adaptive filter system for filtering undesired periodic and/or correlated interference signals contained in the same frequency band as a desired input signal. The filter system is capable of filtering at least two sinusoidal interference signals and incorporates a negative feedback loop having a transfer function of that of narrow band-pass multiple filter. The feedback loop using interference frequencies generates a corresponding interference enhanced output signal. This enhanced output signal is combined with the input signal whereby to produce an error signal which corresponds to the desired signal contained in the input frequency band. A double or quadruple filter system is also described as examples of the present invention. The filter system is suitable for removing modulated sinusoidal interference and particularly for reducing TV co-channel interference.Other References
| |
