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EP0386874A2
Expired / Lapsed
EP
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Frequency synchronization of stations of a communication system
Assignee: Plessey Semiconductors Ltd
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Filing: 1990-01-23
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Granted: —
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Expires: 2010-01-23
Abstract
Abstract A narrow band modulation UHF/Microwave communication system comprises a transmit/receive base station having a plurality of transmitter for transmitting information at respective UHF/Microwave channel frequencies to a plurality of remote transmit/receive stations, in which the transmitters at the base station are served in common by a single master oscillator and in which a single reference frequency signal is derived from the master oscillator at the base station and transmitted to all of said remote stations where it serves to provide for frequency locking of the oscillators at said stations to produce synchronisation between the frequencies at the base station and the remote stations.
Inventors
- 👤 Peter Henry Saul
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-05 17:10
CPC Classifications
H; H04; H04B; H04B7/00; H04B7/24
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
103 words
A narrow band modulation UHF/Microwave communication system comprising a transmit/receive base station having a plurality of transmitter for transmitting information at respective UHF/Microwave channel frequencies to a plurality of remote transmit/receive stations, in which the transmitters at the base station are served in common by a single master oscillator and in which a single reference frequency signal is derived from the master oscillator at the base station and transmitted to all of said remote stations where it serves to provide for frequency locking of the oscillators at said stations to produce synchronisation between the frequencies at the base station and the remote stations.
Claim 2
Dependent Claim
103 words
A narrow band modulation UHF/Microwave communication system comprising a transmit/receive base station having a plurality of transmitter for transmitting information at respective UHF/Microwave channel frequencies to a plurality of remote transmit/receive stations, in which the transmitters at the base station are served in common by a single master oscillator and in which a single reference frequency signal is derived from the master oscillator at the base station and transmitted to all of said remote stations where it serves to provide for frequency locking of the oscillators at said stations to produce synchronisation between the frequencies at the base station and the remote stations.
Claim 3
Dependent Claim
35 words
A narrow band modulation UHF/Microwave communication system as claimed in Claim 1, in which the reference frequency signal is well separated from the transmitted channel frequencies having a narrow frequency spacing and containing transmitted information.
Claim 4
Dependent Claim
31 words
A narrow band modulation UHF/Microwave communication system as claimed in Claim 1 or Claim 2, in which the reference frequency signal is transmitted periodically without modulation to the remote transmit/receive stations.
Claim 5
Dependent Claim
42 words
A narrow band modulation UHF/Microwave communication system as claimed in Claim 3, in which the reference frequency signal is transmitted to all of the remote stations simultaneously under the control of control signals applied to the transmitter of the reference frequency signal.
Claim 6
Dependent Claim
56 words
A narrow band modulation UHF/Microwave communication system as claimed in any preceding claim, in which the reference frequency signal is received by a reference signal receiver of the receiver part of each remote station which includes a local oscillator under the control of a slave oscillator which in turn is controlled by a frequency locking device.
Claim 7
Dependent Claim
36 words
A narrow band modulation UHF/Microwave communication system as claimed in Claim 5, in which the slave oscillator also controls the local oscillator of each channel frequency signal receiver of the receiver part of each remote station.
Claim 8
Dependent Claim
56 words
A narrow band modulation UHF/Microwave communication system as claimed in Claim 5 or Claim 6, in which the slave oscillator in the receiver part of each remote station controls a slave oscillator in the associated transmitter part of the same station, the latter slave oscillator controlling a local oscillator in the transmitter of the remote station.
Claim 9
Dependent Claim
50 words
A narrow band modulation UHF/Microwave communication system as claimed in Claim 7, in which the master oscillator of the base station controls a slave oscillator in the receiver part of the base station which in turn controls the local oscillators of respective receivers for receiving transmitted signals from remote stations.
References Cited (Backward Citations)
No citation records indexed.
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