Adaptive detector

US4243935A · kind A · utility

Assignee

• United States of America as represented by the Secretary of the Air Force · US

Inventors

• John M. McCool · El Cajon, US
• Bernard Widrow · Stanford, US
• Robert H. Hearn · Burns Lake, CA
• James R. Zeidler · San Diego, US
• Douglas M. Chabries · Salem, US
• Randall H. Moore · San Diego, US

Key dates

• Filing date: May 18, 1979
• Grant date: Jan 6, 1981
• Expiry date: May 18, 1999

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S367/901
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

An adaptive detector comprises an adaptive linear prediction filter (ALPF) nd a detection processor. The adaptive filter comprises an input filter, adapted to receive an input signal x(k) and delay it by a time .DELTA.. An L-point, or L-tap, adaptive filter has an input connected to the output of the input filter, a signal r(k) appearing at the output of the filter. A means for summing has two inputs, one for receiving the signal x(k) and the other for receiving an inverted signal from the adaptive filter, the output of the summer being an error signal .epsilon.(k). A feedback amplifier, whose input is connected to the output of the summer, takes a portion 2.mu., of the output signal .epsilon.(k) and feeds it back to the adaptive filter, thereby modifying the tap weights of the adaptive filter. The detection processor comprises a circuit, whose input is connected to the output of the adaptive filter, to receive the signal r(k), for performing a K-point discrete Fourier transform (DFT) on the signal r(k). A spectral analyzer, whose input is connected to the output of the DFT circuit, performs a spectral analysis on the output signal.