US3742149A
Expired / Lapsed
US
⏱️ 0.0 years remaining
A frequency division multiplex microwave communication system using polarization division multiplex technique
Assignee: NEC Corp
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Filing: 1971-04-30
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Granted: 1973-06-26
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Expires: 1991-04-30
Abstract
Abstract A signal transmission and reception system which includes means for transmitting a plurality of information signals each of which occupies a different frequency band. The information signals, which may correspond to television signals, amplitude-modulate a carrier wave to produce single side band components of the modulated carrier wave, each single side band component corresponding to a different information signal. The components are combined into two groups of side band components each group being comprised of side band components corresponding to alternate, adjacent information signal frequency bands. The two composite signals are transmitted by transmitter means which uniquely polarize each composite signal with respect to the other. Receiving means, responsive to each of the polarized signals, detect the composite signals and apply each to a different demodulator. The demodulated signals are combined to reconstruct the information contained in the plurality of transmitted information signals.
Inventors
- 👤 H Yoshida
- 👤 K Narahara
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 17:34
CPC Classifications
H; H04; H04J; H04J1/00; H04J1/02; H04J1/08; H04J1/085; H04B; H04B7/00; H04J1/12; H04N; H04N7/00; H04N7/20
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
157 words
A frequency division multiplex signal transmission system for transmitting a plurality of information signals each occupying a distinct, non-overlapping frequency band and each occupying substantially the same frequency band width, comprising: a plurality of modulator means for amplitude-modulating a carrier Wave by each of said information signals to produce a plurality of single side band components of the modulated carrier wave, said single side band components being separated from each other in frequency domain; first and second combiner means for combining every other ones of said single side band components to produce first and second single side band component groups, respectively, each group being comprised of side band components corresponding to alternate, adjacent frequency bands; means for transmitting said two sideband component groups as a horizontally polarized carrier wave and a vertically polarized carrier wave, respectively; and means at the receiving site responsive to each of the polarized carrier waves for demodulating said side band components respectively.
Claim 2
Dependent Claim
157 words
A frequency division multiplex signal transmission system for transmitting a plurality of information signals each occupying a distinct, non-overlapping frequency band and each occupying substantially the same frequency band width, comprising: a plurality of modulator means for amplitude-modulating a carrier Wave by each of said information signals to produce a plurality of single side band components of the modulated carrier wave, said single side band components being separated from each other in frequency domain; first and second combiner means for combining every other ones of said single side band components to produce first and second single side band component groups, respectively, each group being comprised of side band components corresponding to alternate, adjacent frequency bands; means for transmitting said two sideband component groups as a horizontally polarized carrier wave and a vertically polarized carrier wave, respectively; and means at the receiving site responsive to each of the polarized carrier waves for demodulating said side band components respectively.
Claim 3
Dependent Claim
92 words
A signal transmission system of claim 1 wherein said means at the receiving site comprises: first receiver means sensitive to the polarization of one of said two side band component groups, second receiver means sensitive to the polarization of the other of said two side band component groups, first and second demodulator means coupled respectively to said first and second receiver means for demodulating respectively said one and other of the two side band component groups and combiner means coupled to said first and second demodulator means for combining the demodulated signals.
Claim 4
Dependent Claim
75 words
The signal transmission system of claim 1 wherein said plurality of amplitude-modulating means comprises a plurality of single side band modulators each receiving a different one of said information signals and said carrier wave, said first combiner means comprising first circulator means coupled to a group of said plurality of modulators receiving single side band components occupying alternate, adjacent frequency bands said second combiner means comprising a second circulator means coupled to the remaining modulators.
Claim 5
Dependent Claim
51 words
The signal transmission system of claim 2 wherein said means at the receiver site further includes filter means coupled to the output of each of said demodulation means for suppressing the third harmonic cross modulation components appearing in the regions adjacent to the frequency bands occupied by said side band components.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-06-25 | 1976-12-25 | 1977-06-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-06-25 | 1980-12-25 | 1981-06-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-06-25 | 1984-12-25 | 1985-06-26 | $7700.00 | Window Closed / Lapsed |