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US4497067A
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US
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Interference cancellation type space diversity system
Assignee: NEC Corp
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Filing: 1983-07-11
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Granted: 1985-01-29
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Expires: 2003-07-11
Abstract
Abstract An interference cancellation type space diversity system transmits digital microwaves in a sure and stable manner. Signals coming in through two spaced antennas are combined together into a single input signal and the composite signal is processed by a demodulator into a baseband signal which is identical with a transmitted signal. The demodulated baseband signal is processed by a frequency/amplitude characteristic detector network, which comprises a correlation circuit and an identification circuit, thereby controlling output phases of the antennas.
Inventors
- 👤 Junji Namiki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 17:30
CPC Classifications
H; H04; H04L; H04L1/00; H04L1/02; H04L1/06; H04B; H04B1/00; H04B1/06; H04B1/10; H04B1/12; H04B1/123; H04B1/126
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
142 words
An interference cancellation type space diversity system for receiving signals coming in through two spaced antennas and a combiner means for combining the input signals into a single signal, said system comprising: phase shifter means for controlling the output phase of one of the antennas; comparator means for comparing intensities of the signals individually received by the antennas; demodulator means for getting baseband signals from a combined output of the antennas; correlator means for producing at least one correlation between an output of the demodulator means and a plurality of signals obtained by processing said output of the demodulator means; identification means for identifying a sign of an imaginary part of at least one of the correlations; and means for controlling a phase in the phase shifter means in response to the comparison result of the comparator means and the identification means.
Claim 2
Dependent Claim
142 words
An interference cancellation type space diversity system for receiving signals coming in through two spaced antennas and a combiner means for combining the input signals into a single signal, said system comprising: phase shifter means for controlling the output phase of one of the antennas; comparator means for comparing intensities of the signals individually received by the antennas; demodulator means for getting baseband signals from a combined output of the antennas; correlator means for producing at least one correlation between an output of the demodulator means and a plurality of signals obtained by processing said output of the demodulator means; identification means for identifying a sign of an imaginary part of at least one of the correlations; and means for controlling a phase in the phase shifter means in response to the comparison result of the comparator means and the identification means.
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) | 1988-01-29 | 1988-07-30 | 1989-01-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-01-29 | 1992-07-30 | 1993-01-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-01-29 | 1996-07-30 | 1997-01-29 | $7700.00 | Window Closed / Lapsed |