Patent US4903340A successfully refreshed from Google Patents.
Patent EP0213780A2 successfully refreshed from Google Patents.
EP0213780A2
Expired / Lapsed
EP
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Burst-mode two-way communications system
Assignee: Libera Telecom Ltd
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Filing: 1986-08-05
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Granted: —
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Expires: 2006-08-05
Abstract
Abstract A burst-mode two-way radio communications system in which transceivers (26) at a base station (20) share a common antenna arrangement having two or more branches (22, 24) and antenna branch selection is made by an operative base station transceiver having regard to the strength of the signal received from a portable transceiver with which communication is established, antenna branch selection being effected by a switch (30) controlled by a switch controller (28), such as an OR-selector, which is connected to all the base station transceivers in order to receive from any such transceiver a switching instruction signal.
Inventors
- 👤 Graham Leslie Maile
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-03 07:49
CPC Classifications
H; H04; H04B; H04B7/00; H04B7/02; H04B7/04; H04B7/08; H04B7/0802
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
106 words
A burst-mode two-way radio communications system wherein a plurality of transceivers at a base station share a common antenna arrangement having a plurality of antenna branches and antenna branch selection is made by an operative base station transceiver having regard to the strength of the signal received from a portable transceiver with which communication is established, characterised in that selection of an antenna branch (22, 24) is effected by one or more switches (30) controlled by a switch controller (28 or 50) which is connected to all the base station transceivers (26) to receive from any one of them a signal which instructs antenna branch selection.
Claim 2
Dependent Claim
106 words
A burst-mode two-way radio communications system wherein a plurality of transceivers at a base station share a common antenna arrangement having a plurality of antenna branches and antenna branch selection is made by an operative base station transceiver having regard to the strength of the signal received from a portable transceiver with which communication is established, characterised in that selection of an antenna branch (22, 24) is effected by one or more switches (30) controlled by a switch controller (28 or 50) which is connected to all the base station transceivers (26) to receive from any one of them a signal which instructs antenna branch selection.
Claim 3
Dependent Claim
71 words
A burst-mode two-way radio communications system according to claim l, characterised by a plurality of switches, one for each base station transceiver, controlled by a switch selector (50) which, while being responsive to an instructing signal received from any one of the base station transceivers, acts to control all the switches simultaneously, so that at any given time all the transceivers (26) are connected to the same antenna branch (22, 24).
Claim 4
Dependent Claim
50 words
A burst-mode two-way radio communications system according to claim l, characterised by a single switch (30) controlled by an OR selector (28), all the base station transceivers (26) having a common connection to the switch, while the OR selector responds to instructing signals received from any one of such transceivers.
Claim 5
Dependent Claim
26 words
A burst-mode two-way radio communications system according to any of claims l to 5, characterised in that the common antenna arrangement has two branches (22, 24).
Claim 6
Dependent Claim
41 words
A burst-mode two-way radio communications system according to any of claims l to 4, characterised in that the antenna spacing is adjustable, more especially to be one quarter wavelength or a simple multiple thereof at the operating frequency of the carrier.
Claim 7
Dependent Claim
49 words
A burst-mode two-way radio communications system according to any of claims l to 5, characterised by means (20) for monitoring the level of the signal received at a transceiver and for causing the antenna branch to be switched dependently on said signal level falling below an adjustable absolute value.
Claim 8
Dependent Claim
32 words
A burst-mode two-way radio communications system according to claim 6, characterised in that the monitoring means comprises means to sample-and-hold the received signal and monitor the rate of change of successive samples.
Claim 9
Dependent Claim
51 words
A burst-mode two-way radio communications system according to claim 7, characterised in that the monitoring means also includes means for examining the received signal for corrupted information and for correlating the extent of corrupted information with the monitored rate of change of the signal in order to determine antenna branch switching.
Claim 10
Dependent Claim
70 words
A burst-mode two-way radio communications system according to any of claims l to 8, operating with a carrier signal and a speech signal subject to digital coding and modulation, characterised in that the base station transceivers and portable transceivers communicate by alternate transmission with a time limited burst period in each direction, and in that the antenna branching switching period does not exceed one bit of the coded speech signal.
Claim 11
Dependent Claim
85 words
l0. A burst-mode two-way radio communications system according to any of claims l to 9, characterised by means for bringing the switch controller into operation only after coupling has been established between the base station and any one portable transceiver, means for suppressing a second antenna switching following a first switching by less than a given time period, and means for monitoring the number of antenna switchings in a given time period and for de-activating the switch controller if said number exceeds a given value.
References Cited (Backward Citations)
US3475686A
Cited
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