US3665472A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Two-way communication system employing two-clock frequency pseudo-noise signal modulation
Assignee: Unisys Corp
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Filing: 1969-10-08
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Granted: 1972-05-23
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Expires: 1989-10-08
Abstract
Abstract A digital two-way communication system utilizing RF transmissions that are phase-shift-keyed (PSK) by binary pseudonoise (PN) code generators operating at different clock rates. Transmissions in the first and second directions are modulated by composite PN code generators operating at different first and second clock frequencies f1 and f2, respectively, where f1 Nf2, with N being a positive integer having no factors in common with the lengths of the component PN codes from which the composite is formed. The binary digital data signals that are to be transmitted in either direction modulate a binary PN code which is a composite code generated from a plurality of component PN codes. Each of these data-modulated composite PN codes, which are generated at clock frequencies f1 and f2, respectively, modulates, in turn, an RF carrier signal. By having the two communication stations transmit and receive at different PN clock frequencies, equipment limitations that restrict transmitter performance in the second direction need not limit performance in the first direction, thereby allowing a higher clock frequency f1, in the first direction and subsequent lower power required at the receiver at the other end for the same SNR out of the receiver.
Inventors
- 👤 Earl M Kartchner
- 👤 Gary R Van Horn
- 👤 Richard A Wallace
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 10:27
CPC Classifications
H; H04; H04L; H04L5/00; H04L5/14; H04L5/143
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
118 words
A communication system, comprising: first and second transmit/receive stations; each of said first and second stations including an associated transmitter means and an associated receiver means; each of said first and second stations including an associated two clock-frequency PN generator means for generating a first PN code of a bit frequency f1 and a second PN code of a bit frequency f2, where f1 Nf2 with N being a positive integer greater than one; each of said PN generator means of said first and second stations controlling the associated receiver and transmitter for enabling said first and second stations to transmit to said second and first stations, respectively, at said different PN clock frequencies f1 and f2, respectively.
Claim 2
Dependent Claim
118 words
A communication system, comprising: first and second transmit/receive stations; each of said first and second stations including an associated transmitter means and an associated receiver means; each of said first and second stations including an associated two clock-frequency PN generator means for generating a first PN code of a bit frequency f1 and a second PN code of a bit frequency f2, where f1 Nf2 with N being a positive integer greater than one; each of said PN generator means of said first and second stations controlling the associated receiver and transmitter for enabling said first and second stations to transmit to said second and first stations, respectively, at said different PN clock frequencies f1 and f2, respectively.
Claim 3
Dependent Claim
11 words
The communication system of claim 1 wherein said modulation is phase-shift-keyed.
Claim 4
Dependent Claim
296 words
A communication system, comprising: first and second transmit/receive stations; each of said first and second stations including an associated transmitter means and an associated receiver means; each of said first and second stations including associated first and second PN generator means for generating a first PN code of a PN bit frequency f1 and of a PN bit time (1/f1) and a second PN code of a PN bit frequency f2 and of a PN bit time (1/f2), where f1 Nf2 with N being a positive integer; means coupling the first and second PN codes generated by said first stations''s PN generator means to the associated transmitter means and the associated receiver means, respectively, for controlling said associated transmitter means to modulate a to-be-transmitted carrier signal with a PN signal generated at a clock-frequency f1 and for controlling said associated receiver means to demodulate the transmission signal received from a said second station which signal was modulated by a PN signal generated at a clock-frequency f2; means coupling the first and second PN codes generated by said second station''s PN generator means to the associated receiver means and the associated transmitter means, respectively, for controlling said associated receiver means to demodulate the transmission signal received from said first station which signal was modulated by a PN signal generated at a clock-frequency f1 and for controlling said associated transmitter means to modulate a to-be-transmitted carrier signal with a PN signal generated at a clock-frequency f2; each of Said PN generator means of said first and second stations controlling the associated receiver and transmitter for enabling said first and second stations to transmit signals to said second and first stations, respectively, which signals are modulated by PN signals generated at said different clock frequencies f1 and f2, respectively.
Claim 5
Dependent Claim
296 words
A communication system, comprising: first and second transmit/receive stations; each of said first and second stations including an associated transmitter means and an associated receiver means; each of said first and second stations including associated first and second PN generator means for generating a first PN code of a PN bit frequency f1 and of a PN bit time (1/f1) and a second PN code of a PN bit frequency f2 and of a PN bit time (1/f2), where f1 Nf2 with N being a positive integer; means coupling the first and second PN codes generated by said first stations''s PN generator means to the associated transmitter means and the associated receiver means, respectively, for controlling said associated transmitter means to modulate a to-be-transmitted carrier signal with a PN signal generated at a clock-frequency f1 and for controlling said associated receiver means to demodulate the transmission signal received from a said second station which signal was modulated by a PN signal generated at a clock-frequency f2; means coupling the first and second PN codes generated by said second station''s PN generator means to the associated receiver means and the associated transmitter means, respectively, for controlling said associated receiver means to demodulate the transmission signal received from said first station which signal was modulated by a PN signal generated at a clock-frequency f1 and for controlling said associated transmitter means to modulate a to-be-transmitted carrier signal with a PN signal generated at a clock-frequency f2; each of Said PN generator means of said first and second stations controlling the associated receiver and transmitter for enabling said first and second stations to transmit signals to said second and first stations, respectively, which signals are modulated by PN signals generated at said different clock frequencies f1 and f2, respectively.
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) | 1975-05-23 | 1975-11-22 | 1976-05-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-05-23 | 1979-11-22 | 1980-05-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-05-23 | 1983-11-22 | 1984-05-23 | $7700.00 | Window Closed / Lapsed |