Signal harmonic processor
AssigneeSperry Corporation
InventorsClarence L. Bennett, Jr., Robert D. Short, III
Life of this patent
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Abstract
A signal processor for detecting the presence of two signals whose over-all phase or frequency is related by a known rational number. The first signal of frequency .omega.M is raised to the N.sup.th power, while the second signal of frequency .omega.N is raised to the M.sup.th power. The two raised signals are then correlated, energy detected, and compared against a predetermined threshold to provide an indication when both signals are present. By utilizing the known frequency relationship between the two signals the processor yields enhanced detection performance over that achievable by detection of each signal separately.
Claims18
A method for detecting, in an incoming signal, the common presence of a first signal of frequency .omega.M and a second signal of frequency .omega.N related by a known rational number M/N comprising
- (a) filtering the incoming signal to extract said first signal;
- (b) raising said first signal to the N.sup.th power, thereby providing a first raised signal;
- (c) filtering the incoming signal to extract said second signal;
- (d) raising said second signal to the M.sup.th power, thereby providing a second raised signal;
- (e) correlating the first raised signal with the second raised signal, thereby producing a correlated signal;
- (f) detecting the energy of said correlated signal, thereby providing a detected signal;
- and
- (g) producing a report signal, indicating the common presence of said first and second signals, when the energy of said correlated signal exceeds a predetermined level.
Dependencies are inferred from the claim text.