04100378 is referenced by 26 patents and cites 7 patents.

Cross-correlation arrangement for determining the presence or absence of a signal x.sub.2 (t) of known frequency in an unknown signal x.sub.1 (t) if this signal x.sub.2 (t) is present for at least a period of time .tau..sub.o with an unknown starting instant. An auxiliary signal a.sub.1 (t) is added to the signal x.sub.2 (t). The sum signal is converted into one-bit code words s(nT) which are multiplied in at least a first correlation channel by one-bit code words y.sub.per (kT) which are stored in a storage medium having at least N/2 addressable storage locations. The code words y.sub.per (kT) are elements of a series {y.sub.per (kT)} which is formed by the code words which occur in a predetermined time interval having a length NT and which are of a non-periodical signal of the form sign [x.sub.2 (t) + a.sub.2 (t)]. The product code words obtained are added together in an integrator. This integrator is read each time after a time interval NT and reset. The absolute value of an output code word of the integrator is optionally added to corresponding code words of other correlation channels. The sum code words obtained in this way are integrated in a second integrator whose contents is continuously compared with a detection level. If N.sub.o = .tau..sub.o /T, N is smaller than N.sub.o for example a factor of 3. The value of N determines the width of the detection characteristic.

Title
Cross-correlation arrangement
Application Number
5/728796
Publication Number
4100378
Application Date
October 1, 1976
Publication Date
July 11, 1978
Inventor
Johannes Bernhard Heinrich Peek
Eindhoven
NL
Theodoor Antonius Carel Maria Claasen
Eindhoven
NL
Agent
Henry I Steckler
Frank R Trifari
Assignee
U S Philips Corporation
NY, US
IPC
H04M 1/50
G01R 23/02
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