Accession Number : ADD003838

Title :   Multi-Path Signal Enhancing Apparatus.

Descriptive Note : Patent,

Corporate Author : DEPARTMENT OF THE NAVY WASHINGTON D C

Personal Author(s) : Medwin,Herman

Report Date : 12 Apr 1977

Pagination or Media Count : 5

Abstract : A plurality of processing channels each receive one of a number of direct and secondary signal energy rays. Each channel includes an A/D converter and computer the logic of which is controlled by a Fast Fourier Transform (FFT) algorithm to produce a plurality of data outputs each containing the amplitude and phase information of selected frequencies present in the channel input. To enhance signal detection and minimize signal strength fluctuations, each of the selected frequency outputs of each channel FFT is compared with each identical frequency output of other channel FFT's. Phase compensation means such as a shift register adjusts the phase relationship between all identical FFT outputs to permit their amplitudes to be constructively added. The individual subtotals so produced are totalled to provide an output representing the combined strength of the multi-path signal energy. In particular, medium interfaces such as an air-sea or air-ground interface, produce wide variations in the incoming direction of the signal energy to be detected. (Author)

Descriptors :   *Patents, *Signal processing, Analog to digital converters, Fast fourier transforms, Multipath transmission, Algorithms, Shift registers

Subject Categories : Acoustic Detection and Detectors

Distribution Statement : APPROVED FOR PUBLIC RELEASE