Patent US4525835A successfully refreshed from Google Patents.
US4525835A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Duplex radio system utilizing time compression expansion
Assignee: Nortel Networks Ltd
•
Filing: 1982-10-06
•
Granted: 1985-06-25
•
Expires: 2002-10-06
Abstract
Abstract A multichannel duplex radio system for cordless telephone in which digital information is sent between the two ends. The data is divided into blocks which are transmitted in a fraction of the original block length. The other time slots are used for the duplex return path and for other similar equipment operating nearby. A direct conversion radio receiver is used in which the local oscillator signal is modulated for transmission.
Inventors
- 👤 Ian A. W. Vance
- 👤 Stephen D. Bainton
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 23:01
CPC Classifications
H; H04; H04L; H04L25/00; H04L25/02; H04L25/05; H04B; H04B1/00; H04B1/38; H04B1/40; H04B1/54; H04B1/56; H04B1/66; H04B1/662; H04B7/00; H04B7/24; H04B7/26; H04B7/2643; H04M; H04M1/00; H04M1/72; H04M1/725; H04M1/72502; H04M1/72505; H04M1/72511; H04B1/403; H04B1/408
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
238 words
A duplex radio system having a plurality of terminals each operative for transmitting outgoing signals and receiving incoming signals on any of a plurality of transmission channels which can thus have a used or unused status, each of said plurality of terminals comprising: a direct conversion receiver having a receiver input that has the incoming signals coupled thereto during operation in a receive mode, and a receiver output; local oscillator means having a control input and an oscillator output and operative for generating and presenting at said oscillator output an output signal at a carrier frequency modulated with any modulating signal supplied to said control input, said oscillator output being coupled to said receiver input to supply thereto at least during operation in said receive mode the output signal of said oscillator means at said carrier frequency; compression means for time compressing data, including an output connected to said control input of said oscillator means to supply the time compressed data to said control input as said modulating signal; expansion means for time expanding data received, including an input coupled to said receiver output; and control means having outputs coupled to said compression means and said expansion means to control modulating of said oscillator means with said modulating signal and hence transmission of said time compressed data to be transmitted during a transmit mode of operation, and expansion of said received data during the receive mode of operation.
Claim 2
Dependent Claim
238 words
A duplex radio system having a plurality of terminals each operative for transmitting outgoing signals and receiving incoming signals on any of a plurality of transmission channels which can thus have a used or unused status, each of said plurality of terminals comprising: a direct conversion receiver having a receiver input that has the incoming signals coupled thereto during operation in a receive mode, and a receiver output; local oscillator means having a control input and an oscillator output and operative for generating and presenting at said oscillator output an output signal at a carrier frequency modulated with any modulating signal supplied to said control input, said oscillator output being coupled to said receiver input to supply thereto at least during operation in said receive mode the output signal of said oscillator means at said carrier frequency; compression means for time compressing data, including an output connected to said control input of said oscillator means to supply the time compressed data to said control input as said modulating signal; expansion means for time expanding data received, including an input coupled to said receiver output; and control means having outputs coupled to said compression means and said expansion means to control modulating of said oscillator means with said modulating signal and hence transmission of said time compressed data to be transmitted during a transmit mode of operation, and expansion of said received data during the receive mode of operation.
Claim 3
Dependent Claim
54 words
A system according to claim 1, wherein said compression means includes a first digital memory to receive and store generated data at a first rate and to produce said data to be transmitted at a second rate faster than said first rate so that said data to be transmitted is a burst of data.
Claim 4
Dependent Claim
43 words
A system according to claim 2, wherein said expansion means includes a second digital memory to receive and store said burst of data at a third rate and to produce said expanded received data at a fourth rate slower than said third rate.
Claim 5
Dependent Claim
39 words
A system according to claim 1, wherein said expansion means includes a digital memory to store said received data at a first rate and to produce said expanded received data at a second rate slower than said first rate.
Claim 6
Independent Claim
68 words
A system according to claims 1, 2, 3 or 4, further including switching means coupled to an antenna, said receiver and said oscillator means being controlled by said control means in synchronization with said compression means and said expansion means to couple said oscillator means to said antenna during operation of said comression means and to couple said receiver to said antenna during operation of said expansion means.
Claim 7
Dependent Claim
31 words
A system according to claim 5, wherein said control means is coupled to said receiver output and includes means for deriving channel status information from the output signal of said receiver.
Claim 8
Dependent Claim
19 words
A system according to claim 5, further comprising means for inputting channel status information to said control means locally.
Claim 9
Independent Claim
35 words
A system according to claims 1, 2, 3 or 4, wherein said control means is coupled to said receiver output and includes means for deriving channel status information from the output signal of said receiver.
Claim 10
Independent Claim
23 words
A system according to claims 1, 2, 3 or 4, further comprising means for inputting channel status information to said control means locally.
References Cited (Backward Citations)
US2056031A
Cited
US2948808A
Cited
US3573379A
Cited
US3636524A
Cited
US3827052A
Cited
GB1474726A
Cited
US4034295A
Cited
GB1486547A
Cited
GB1479313A
Cited
GB1556087A
Cited
EP0016336A1
Cited
US4349919A
Cited
GB2064921A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-06-24 | 1988-12-24 | 1989-06-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-06-24 | 1992-12-24 | 1993-06-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-06-24 | 1996-12-24 | 1997-06-25 | $7700.00 | Window Closed / Lapsed |