US4334316A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pre-detection maximal ratio combining system for diversity reception of radio frequency signals
Assignee: NEC Corp
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Filing: 1980-10-28
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Granted: 1982-06-08
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Expires: 2000-10-28
Abstract
Abstract A pre-detection maximal ratio combining system for a plurality of received signals is provided in which a plurality of control devices are arranged for controlling the phase and amplitude of each of a number of pre-detection signals corresponding to the received signals. The control devices operate by correlating the mutually orthogonal components of the pre-detection signals with a reference comparison signal, which is derived by combining the outputs of the several control devices into a combined signal, and normalizing the amplitude thereof.
Inventors
- 👤 Motomichi Tanaka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 19:36
CPC Classifications
H; H04; H04B; H04B7/00; H04B7/02; H04B7/04; H04B7/08; H04B7/0837; H04B7/0842; H04B7/0848; H04B7/0857
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
126 words
A system for pre-detection maximal ratio combining of a plurality of received diversity signals, comprising: a plurality of control means for controlling the phase and amplitude of each of a plurality of pre-detection signals, each of said control means including means to derive, from a respective pre-detection diversity signal, a set of mutually orthogonal components, means to correlate each component with a reference comparison signal and means to provide a control means output signal in response to the output of said correlation means. means for combining the outputs of said plurality of control means to produce a combined signal; and means for normalizing the amplitude of the combined signal and respectively supplying this normalized signal, as said reference comparison signal, to said plurality of control means.
Claim 2
Independent Claim
126 words
A system for pre-detection maximal ratio combining of a plurality of received diversity signals, comprising: a plurality of control means for controlling the phase and amplitude of each of a plurality of pre-detection signals, each of said control means including means to derive, from a respective pre-detection diversity signal, a set of mutually orthogonal components, means to correlate each component with a reference comparison signal and means to provide a control means output signal in response to the output of said correlation means. means for combining the outputs of said plurality of control means to produce a combined signal; and means for normalizing the amplitude of the combined signal and respectively supplying this normalized signal, as said reference comparison signal, to said plurality of control means.
Claim 3
Dependent Claim
162 words
A system for pre-detection maximal ratio combining of a plurality of received diversity signals as claimed in claim 1, wherein each of said plurality of control means comprises: first phase shifting means for shifting the phase of said pre-detection signal by 90 degrees; means for delaying said pre-detection signal by a prescribed length of time; second phase shifting means for shifting the phase of the output of said delay means by 90 degrees; first and second multiplying means for respectively multiplying the outputs of said delaying means and said second phase shifting means by said reference comparison signal; first and second low pass filtering means for respectively filtering the outputs of said first and second multiplying means; third and fourth multiplying means for respectively multiplying said pre-detection signal and the output of said first phase shifting means by the outputs of said first and second low pass filtering means; and means for adding the outputs of said third and fourth multiplying means.
Claim 4
Dependent Claim
171 words
A system for pre-detection maximal ratio combining of a plurality of received diversity signals as claimed in claim 1, wherein each of said plurality of control means comprises: first phase shifting means for shifting the phase of said pre-detection signal by 90 degrees; means for delaying said pre-detection signal by a prescribed length of time; second phase shifting means for shifting the phase of said reference comparison signal by 90 degrees; first and second multiplying means for respectively multiplying the output of said delaying means by said reference comparison signal and the output of said second phase shifting means; first and second low pass filtering means for respectively filtering the outputs of said first and second multiplying means; third and fourth multiplying means for respectively multiplying the outputs of said first and second low pass filtering means by said pre-detection signal and the output of said first phase shifting means; and means for subtracting the output of said fourth multiplying means and that of said third multiplying means from each other.
References Cited (Backward Citations)
US3609663A
Cited
US4079380A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-06-07 | 1985-12-07 | 1986-06-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-06-07 | 1989-12-07 | 1990-06-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-06-07 | 1993-12-07 | 1994-06-08 | $7700.00 | Window Closed / Lapsed |