Accession Number : ADD008888

Title :   Circuit for the Adaptive Suppression of Narrow Band Interference.

Descriptive Note : Patent,

Corporate Author : DEPARTMENT OF THE AIR FORCE WASHINGTON DC

Personal Author(s) : Eaton,William G ; Roeder,Allan W

Report Date : 01 Sep 1981

Pagination or Media Count : 7

Abstract : Adaptive suppression of narrow band interference is realized by a filter that automatically makes estimates of interfering signals in the frequency domain and separates the interference from the desired signal. Received analog signals are Fourier transformed in accordance with a CHIRP Z algorithm, squared, and filtered by an N point serial structural CCD to provide a smoothed power spectral density signal. The smoothed power spectral density signal is utilized to cancel interfering signals by any one of three mechanizations. One mechanization comprehends a threshold circuit that generates binary signals in response to the CCD output. The binary signals control a gate that gates strong frequency components (the estimates of the interfering frequency coefficient) from the Fourier transformer through to an inverse Fourier transformer. The inverse Fourier transformed strong frequency components are then subtracted from the delayed received analog signal.

Descriptors :   *Patents, *Suppressors, *Adaptive control systems, *Charge coupled devices, Fourier transformation, Power spectra, Analog signals, Delay lines, Fourier analysis, Threshold effects, Analog systems, Spectral energy distribution, Interference, Mechanization, Circuits, Inversion, Coefficients, Parts, Signals, Narrowband, Frequency, Transformers, Control

Subject Categories : Industrial Chemistry and Chemical Processing
      Electrical and Electronic Equipment
      Numerical Mathematics

Distribution Statement : APPROVED FOR PUBLIC RELEASE