US4068311A
Expired / Lapsed
US
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Discrete transform systems using permuter memories
Assignee: United States Department of the Navy
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Filing: 1976-12-03
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Granted: 1978-01-10
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Expires: 1996-12-03
Abstract
Abstract High-speed, high-accuracy, apparatus for performing discrete Fourier and crete cosine transforms, suitable for signal processing applications. The apparatus includes a means for switching an input signal from a sample-and-hold circuit to a circuit which includes an integrator in cascade with an amplifier. The outputs of these two circuits are summed in a first summer to give one term, G 0 , which is proportional to the d-c component of the input signal. In parallel with the integrator and amplifier is a cascade circuit comprising a first permuter, a filter and a second permuter. A permuter is a special type of memory. The outputs of the sample-and-hold circuit and of the second permuter are summed in a second summer, to result in an output comprising the other transformed terms, G 1 , . . . , G N-1 .
Inventors
- 👤 Harper J. Whitehouse
- 👤 Jeffrey M. Speiser
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 14:06
CPC Classifications
G; G06; G06G; G06G7/00; G06G7/12; G06G7/19; G06G7/1907; G11; G11C; G11C27/00; G11C27/02; G11C27/024
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
233 words
Apparatus for taking the discrete transform of a sampled analog input signal, consisting of N data samples, g 0 , g 1 , . . ., comprising: means, connected to the input signal, for connecting the input signal to either of two connections; means, connected to one of the connections of the connecting means, for sampling the first data sample, g 0 , and holding it for 3N time units, means, connected to the other connection of the connecting means, for integrating the input signal, excluding the g 0 sample, for N-1 time units; means, whose input is connected to the output of the integrating means, for amplifying the integrated signal; a first summing means, whose two inputs are connected to the outputs of the means for sampling and holding and of the amplifying means, for summing its two input signals, the output signal being G 0 , the zero frequency term of the transform; a first permuting means, connected to the said other connection of the connecting means, for performing a permutation on its input signal; means, whose input is connected to the output of the first permuting means, for filtering the permuted signals; and second means, having inputs connected to the outputs of the sampling and holding means and of the filtering means, for summing its input signals, and whose output comprises the transformed terms G 1 ....., G N-1 .
Claim 2
Dependent Claim
233 words
Apparatus for taking the discrete transform of a sampled analog input signal, consisting of N data samples, g 0 , g 1 , . . ., comprising: means, connected to the input signal, for connecting the input signal to either of two connections; means, connected to one of the connections of the connecting means, for sampling the first data sample, g 0 , and holding it for 3N time units, means, connected to the other connection of the connecting means, for integrating the input signal, excluding the g 0 sample, for N-1 time units; means, whose input is connected to the output of the integrating means, for amplifying the integrated signal; a first summing means, whose two inputs are connected to the outputs of the means for sampling and holding and of the amplifying means, for summing its two input signals, the output signal being G 0 , the zero frequency term of the transform; a first permuting means, connected to the said other connection of the connecting means, for performing a permutation on its input signal; means, whose input is connected to the output of the first permuting means, for filtering the permuted signals; and second means, having inputs connected to the outputs of the sampling and holding means and of the filtering means, for summing its input signals, and whose output comprises the transformed terms G 1 ....., G N-1 .
Claim 3
Dependent Claim
27 words
The apparatus according to claim 1, further comprising: a second permuting means, interconnected between the filtering means and the second summing means, for permuting its input signal.
Claim 4
Dependent Claim
121 words
The apparatus according to claim 1, for processing a complex input signal, wherein: the means for sampling and holding is a complex means; the means for integrating is a complex integrator, comprising two real integrators, one each for processing the real and imaginary parts of a complex input signal; the amplifying means is a complex amplifier, comprising a pair of real amplifiers, having a gain of one; the first and second permuting means are complex permuters, that is, comprise a real channel permuter and an imaginary channel permuter; the means for filtering is a complex filter; and the two summing means are complex summers; the apparatus thereby being capable of taking the prime discrete Fourier transform of a complex input signal.
Claim 5
Dependent Claim
56 words
The apparatus according to claim 3 wherein: the complex means for filtering comprises: two pairs of transversal filters, one pair for filtering the real part of a complex input signal and the other for filtering the imaginary part of the complex input signal; and two real summers one connected to each of the pairs of summers.
Claim 6
Dependent Claim
24 words
The apparatus according to claim 3, wherein: the complex means for filtering comprises: three transversal filters; and three summers, connected to the three filters.
Claim 7
Dependent Claim
83 words
The apparatus according to claim 1, wherein: the means for sampling and holding is a real means; the means for integrating is a real integrator; the means for amplifying is a real amplifier having a gain of two; the first and second permuting means are real permuters; the means for filtering is a real filter; and the two summing means are real summers; the apparatus thereby being capable of taking the odd discrete cosine transform (ODCT) of an input signal which is real.
Claim 8
Dependent Claim
16 words
The apparatus according to claim 6, wherein: the real means for filtering comprises a transversal filter.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-01-09 | 1981-07-11 | 1982-01-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-01-09 | 1985-07-11 | 1986-01-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-01-09 | 1989-07-11 | 1990-01-10 | $7700.00 | Window Closed / Lapsed |