US5029187A
Expired / Lapsed
US
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Digital correlation receiver
Assignee: Motorola Solutions Inc
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Filing: 1989-05-22
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Granted: 1991-07-02
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Expires: 2009-05-22
Abstract
Abstract A digital correlation receiver, having one or more filters, that uses a modified correlation waveform to undo or eliminate the effects of distortion of the received signal. A distorted information signal is applied to a multiplifer for multiplication by a correlation waveform that has been modified to eliminate the distortion present in the received information signal. The product of the information signal and the correlation waveform is then integrated and a bit decision is made at the output of the integrator. The accuracy of the bit decision is enhanced by the elimination of the effects of the signal distortion.
Inventors
- 👤 Clifford D. Leitch
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 19:11
CPC Classifications
H; H04; H04L; H04L25/00; H04L25/02; H04L25/06
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
54 words
A digital correlation receiver, comprising: receiving means for receiving an information signal, said receiving means producing a distorted information signal for correlation; and correlation means coupled to said receiving means, for correlating the distorted information signal with a correlation waveform preselected to compensate for the effects of the distortion of the distorted information signal.
Claim 2
Dependent Claim
54 words
A digital correlation receiver, comprising: receiving means for receiving an information signal, said receiving means producing a distorted information signal for correlation; and correlation means coupled to said receiving means, for correlating the distorted information signal with a correlation waveform preselected to compensate for the effects of the distortion of the distorted information signal.
Claim 3
Dependent Claim
26 words
The digital correlation receiver, of claim 1, further comprising: a multiplier, coupled to the receiving means, for multiplying the distorted information signal by the correlation waveform.
Claim 4
Dependent Claim
33 words
The digital correlation receiver of claim 2, further comprising: storage means for storing the correlation waveform, said storage means being coupled to the multiplier for application of said correlation waveform to the multiplier.
Claim 5
Dependent Claim
53 words
The digital correlation receiver of claim 3, further comprising: an integrator, coupled to said multiplier, for integrating the product of the distorted information signal and the correlation waveform for a specific period of time, whereby the effects of distortion of the distorted information signal are substantially eliminated at the output of said integrator.
Claim 6
Dependent Claim
51 words
The correlation receiver of claim 4, wherein the correlation waveform comprises a signal that correlates with the information signal before said information signal is distorted by the receiving means, so that the effects of the distortion of the distorted information signal are substantially eliminated at the output of the correlation receiver.
Claim 7
Dependent Claim
68 words
The correlation receiver of claim 5, wherein the correlation waveform comprises the inverse Fourier transform of the quotient of the Fourier transform of a correlation waveform, that correlates with the information signal before said information signal is distorted by the receiving means, divided by the Fourier transform of the impulse response of the receiving means, said Fourier transform of the impulse response being a function of negative frequency.
Claim 8
Dependent Claim
22 words
The correlation receiver of claim 5, wherein the receiving means comprises a filter, said filter causing the distortion of the information signal.
Claim 9
Dependent Claim
14 words
The correlation receiver of claim 7, wherein the filter is an intermediate frequency filter.
Claim 10
Dependent Claim
15 words
The correlation receiver of claim 8, wherein the storage means comprises a read only memory.
Claim 11
Dependent Claim
55 words
A correlation method comprising: (a) receiving an information signal to provide a received signal; (b) filtering said received signal to provide a filtered signal, said filtered signal including a distortion component introduced by filtering; and (c) correlating said filtered signal with a correlation waveform preselected to compensate for said distortion components introduced by said filtering.
Claim 12
Dependent Claim
55 words
A correlation method comprising: (a) receiving an information signal to provide a received signal; (b) filtering said received signal to provide a filtered signal, said filtered signal including a distortion component introduced by filtering; and (c) correlating said filtered signal with a correlation waveform preselected to compensate for said distortion components introduced by said filtering.
Claim 13
Dependent Claim
24 words
The method of claim 10, further comprising the step of (b1) multiplying the distorted information signal with the correlation waveform to generate a product.
Claim 14
Dependent Claim
46 words
The method of claim 11, wherein the correlation step is performed by integrating the product of the distorted information signal and the correlation waveform for a specific period of time, whereby the effects of distortion of the distorted information signal are substantially eliminated after the integration.
Claim 15
Dependent Claim
21 words
The method of claim 12, further comprising the step of storing the correlation waveform for correlation with the distorted information signal.
Claim 16
Independent Claim
96 words
A method for generating a correlation waveform, in a linear-type radio receiver, for correlation with a distorted signal, comprising the steps of: receiving a signal; producing the distorted signal by introducing distortion into the signal, said distortion being produced in the receiver; determining an impulse response that characterizes the distortion caused by the receiver; and distorting a waveform that correlates with the signal before said signal is distorted by the receiver to produce a correlation waveform, so that the effects of the distortion are substantially eliminated after correlation of the distorted signal with the correlation waveform.
Claim 17
Independent Claim
96 words
A method for generating a correlation waveform, in a linear-type radio receiver, for correlation with a distorted signal, comprising the steps of: receiving a signal; producing the distorted signal by introducing distortion into the signal, said distortion being produced in the receiver; determining an impulse response that characterizes the distortion caused by the receiver; and distorting a waveform that correlates with the signal before said signal is distorted by the receiver to produce a correlation waveform, so that the effects of the distortion are substantially eliminated after correlation of the distorted signal with the correlation waveform.
Claim 18
Dependent Claim
82 words
The method of claim 14, further comprising: determining the Fourier transform of a waveform, that correlates with the signal before said signal is distorted by the receiver; determining the Fourier transform of the impulse response of the receiver; determining the quotient of the Fourier transform of the waveform divided by the Fourier transform of the impulse response of the receiver, said Fourier transform of the impulse response being a function of negative frequency; and determining the inverse Fourier transform of said quotient.
References Cited (Backward Citations)
US3573621A
Cited
US4580139A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-07-01 | 1994-12-31 | 1995-07-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-07-01 | 1998-12-31 | 1999-07-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-07-01 | 2002-12-31 | 2003-07-02 | $7700.00 | Window Closed / Lapsed |