US3646334A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Real-time correlator
Assignee: Gemalto Terminals Ltd
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Filing: 1970-05-27
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Granted: 1972-02-29
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Expires: 1990-05-27
Abstract
Abstract In various circumstances, such as the recovery of a signal from a noisy background, two signals x(t) and y(t) are to be correlated. In this invention x(t) is sampled at recurrence period n/fo (n is at least 2). The samples are put into a recirculating memory of circulation time (n+1)fo with erasure of existing samples at point of insertion. The memory is coupled to a multiplier which multiplies the output of the memory with synchronized samples of y(t). The output of the multiplier is applied to an averaging memory. Only one multiplier is used to give the correlation function at n different time delays and hence greatly simplified apparatus is provided.
Inventors
- 👤 Ivar Wold
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 09:54
CPC Classifications
G; G06; G06G; G06G7/00; G06G7/12; G06G7/19; G06G7/1928; G06J; G06J1/00; G06J1/005
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
204 words
A real-time correlator, comprising first and second inputs to receive first and second signals x(t) and y(t) to be correlated, a first signal-sampler connected to said first input to provide samples of x(t) at a recurrence period of n/fo where n is an integer of at least 2 and fo is a given frequency, a recirculating memory having a circulating time of (n+1)/fo, means coupling said first sampler to said recirculating memory to inject each sample of x(t) as it occurs into said recirculating memory with erasure of any previous sample occupying the position in the recirculating memory at which the injected sample is received, means coupling the recirculating memory to a multiplier to apply thereto the sequence of samples circulating in said memory, a second signal-sampler connected to said second input to provide samples of y(t) at said recurrence period n/fo each for an interval of n/fo, means to apply said samples of y(t) to said multiplier, an averaging memory of n stages driven at a clockfrequency fo, and means for applying the output of said multiplier to said averaging memory to provide an output representative of the correlation function of x(t) and y(t) for n different time delays at increments of 1/fo.
Claim 2
Dependent Claim
204 words
A real-time correlator, comprising first and second inputs to receive first and second signals x(t) and y(t) to be correlated, a first signal-sampler connected to said first input to provide samples of x(t) at a recurrence period of n/fo where n is an integer of at least 2 and fo is a given frequency, a recirculating memory having a circulating time of (n+1)/fo, means coupling said first sampler to said recirculating memory to inject each sample of x(t) as it occurs into said recirculating memory with erasure of any previous sample occupying the position in the recirculating memory at which the injected sample is received, means coupling the recirculating memory to a multiplier to apply thereto the sequence of samples circulating in said memory, a second signal-sampler connected to said second input to provide samples of y(t) at said recurrence period n/fo each for an interval of n/fo, means to apply said samples of y(t) to said multiplier, an averaging memory of n stages driven at a clockfrequency fo, and means for applying the output of said multiplier to said averaging memory to provide an output representative of the correlation function of x(t) and y(t) for n different time delays at increments of 1/fo.
Claim 3
Dependent Claim
25 words
A real-time correlator as claimed in claim 1, wherein said recirculating memory is a digital shift register with a feedback path from output to input.
Claim 4
Dependent Claim
22 words
A real-time correlator as claimed in claim 2, and comprising an analogue-to-digital converter connected between said first sampler and said recirculating memory.
Claim 5
Dependent Claim
28 words
A real-time correlator as claimed in claim 3, wherein the multiplier is a hybrid multiplier-to-receiver digital input from said recirculating memory and analogue input from said second sampler.
Claim 6
Dependent Claim
46 words
A real-time correlator according to claim 1, wherein said means coupling said first sampler to said recirculating memory comprise means to break a recirculating path of said recirculating memory to erase a signal therein and means to inject a sample in place of said erased signal.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-02-28 | 1975-08-30 | 1976-02-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-02-28 | 1979-08-30 | 1980-02-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-02-28 | 1983-08-30 | 1984-02-29 | $7700.00 | Window Closed / Lapsed |