EP0112108A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Radio systems
Assignee: Racal Research Ltd
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Filing: 1983-12-05
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Granted: —
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Expires: 2003-12-05
Abstract
Abstract 57 A radio system employs a method of controlling the transmitted power of a radio signal such that a minimum power level for efficient reception is maintained. Data is simultaneously transmitted between two radio stations (10, 20) using an error correction code. Each block of the code is accompanied by a power bit. The transmitted power bit is set high or low in dependance upon whether the number of errors in a sample of received blocks, as determined by processing of the received code, is equal to, above or below a predetermined threshold value. At the other station the received power bit is directed to a power control device (18) and used to adjust the output power of the transmitter of that station by continuously variable slope delta demodulation.
Inventors
- 👤 Michael Naylor
- 👤 David Brash
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-24 01:34
CPC Classifications
H; H04; H04L; H04L1/00; H04L1/004; H04L1/0056; H04L1/0057; H03; H03M; H03M3/00; H03M3/02; H03M3/022; H03M3/024; H04W; H04W52/00; H04W52/04; H04W52/18; H04W52/20
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
113 words
A radio system for simultaneous digital communication between two radio stations using data blocks each of which includes a plurality of message bits and at least one non-message bit, characterised in that each radio station (10,20) includes means for monitoring the transmission received from the other radio station (10,20) and setting the or one non-message bit to be transmitted by the receiving station (20) to the transmitting station (10) to indicate to the transmitting station (10) whether the transmitted signal power is to be increased or decreased to maintain reception, and means (16,17,18) at each station (10,20) for sensing the setting of said non-message bit to adjust the power of the transmitted signal.
Claim 2
Dependent Claim
113 words
A radio system for simultaneous digital communication between two radio stations using data blocks each of which includes a plurality of message bits and at least one non-message bit, characterised in that each radio station (10,20) includes means for monitoring the transmission received from the other radio station (10,20) and setting the or one non-message bit to be transmitted by the receiving station (20) to the transmitting station (10) to indicate to the transmitting station (10) whether the transmitted signal power is to be increased or decreased to maintain reception, and means (16,17,18) at each station (10,20) for sensing the setting of said non-message bit to adjust the power of the transmitted signal.
Claim 3
Dependent Claim
112 words
A system as claimed in Claim 1, characterised in that each data block comprises a plurality of bits which make up an error correcting code adapted to detect the presence of at least one error in said received plurality of bits in each block, said monitoring means comprising means for utilising said code to determine the error level in a sample of the received blocks in relation to a predetermined threshold value and setting said one non-message bit of a block to be transmitted from the receiving station (20) to a value to indicate that the transmitted signal power is to be increased if the error level exceeds said predetermined threshold value.
Claim 4
Dependent Claim
25 words
A system as claimed in claim 2, characterised in that the error level is determined by monitoring the mean time between the occurence of errors.
Claim 5
Dependent Claim
20 words
A system as claimed in claim 2 or 3, characterised in that the error correcting code is a (7,4,1) code.
Claim 6
Independent Claim
49 words
A system as claimed in any one of the preceding claims, characterised in that the sensing means (16,17,18) employs a continuously variable slope delta demodulator to determine the rate at which the transmitted power is to be adjusted in dependence on the setting of the received non-message bits .
Claim 7
Independent Claim
43 words
A system as claimed in any one of the preceding claims, characterised in that the power adjusting means . (18) are arranged such that the time constant of an increase in power is different from the time constant of a decrease in power.
Claim 8
Independent Claim
107 words
A method for use in a radio system wherein two radio stations are transmitting to each other, of controlling the transmitted power of a radio signal such that a minimum power level to ensure efficient reception is maintained, characterised in that the method comprises the steps of detecting at each station (10,20) the error level in the received transmission from the other station (10,20) and periodically transmitting to the other station (10,20) an indication of whether the transmitted power should be increased or decreased in dependence on whether the error level detected immediately prior to tranmission of said indication was above or below a predetermined value respectively.
Claim 9
Independent Claim
107 words
A method for use in a radio system wherein two radio stations are transmitting to each other, of controlling the transmitted power of a radio signal such that a minimum power level to ensure efficient reception is maintained, characterised in that the method comprises the steps of detecting at each station (10,20) the error level in the received transmission from the other station (10,20) and periodically transmitting to the other station (10,20) an indication of whether the transmitted power should be increased or decreased in dependence on whether the error level detected immediately prior to tranmission of said indication was above or below a predetermined value respectively.
Claim 10
Dependent Claim
39 words
A method as claimed in Claim 7, characterised in that digital signals are transmitted between the stations using an error correcting code, each block of said code being accompanied by a bit which is set to provide said indication.
Claim 11
Dependent Claim
28 words
A method as claimed in Claim 7 or 8, characterised in that the rate and sense of the change in transmitted power is determined by the received indication.
Claim 12
Dependent Claim
31 words
A method as claimed in claim 7,8 or 9, characterised in that the step of detecting the error level comprises the step of monitoring the mean time between occurrences of errors.
References Cited (Backward Citations)
No citation records indexed.
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