Cellular mobile radio system power control
First Claim
1. In a digital mobile radio system, a method of regulating the power of signals transmitted by a transmitting unit which is communicating with a corresponding receiving station, the transmitting unit and the corresponding receiving station each having a transmitter and a receiver, said method comprising the steps of:
- (a) calculating a signal path gain between the transmitting unit and the corresponding receiving station;
(b) measuring a co-channel interference power level at the corresponding receiving station;
(c) calculating the product of the reciprocal of said signal path gain, said co-channel interference power level, and a pre-fixed value which corresponds to a minimum target value of the ratio of a received carrier power and a co-channel interference power;
(d) regulating the power of signals transmitted by the transmitting unit according to the value of said product; and
(e) repeatedly performing the steps (a), (b), (c) and (d) wherein the duration between successive performances of the step of regulating the power of signals varies.
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Accused Products
Abstract
The present invention discloses a method of and apparatus for regulating the power of signals transmitted by transmitting units, such as mobiles or base stations, that are using the same channel in a cellular radio system. An iterative process is disclosed in which the demands of synchrony and coordination among the transmitting units are relaxed. The power of the signals converges at a geometric rate to optimal transmission powers, where the optimal transmission powers are defined as the minimum powers required to maintain the ratio of carrier power to co-channel interference power at least as large as some pre-fixed target value obtained from quality of service considerations. As a result of relaxing the demands of synchrony and coordination, expensive clock or timing mechanisms are not required, thereby reducing the costs of power control.
141 Citations
23 Claims
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1. In a digital mobile radio system, a method of regulating the power of signals transmitted by a transmitting unit which is communicating with a corresponding receiving station, the transmitting unit and the corresponding receiving station each having a transmitter and a receiver, said method comprising the steps of:
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(a) calculating a signal path gain between the transmitting unit and the corresponding receiving station; (b) measuring a co-channel interference power level at the corresponding receiving station; (c) calculating the product of the reciprocal of said signal path gain, said co-channel interference power level, and a pre-fixed value which corresponds to a minimum target value of the ratio of a received carrier power and a co-channel interference power; (d) regulating the power of signals transmitted by the transmitting unit according to the value of said product; and (e) repeatedly performing the steps (a), (b), (c) and (d) wherein the duration between successive performances of the step of regulating the power of signals varies. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. In a digital mobile radio system, a method of regulating the power of signals transmitted by a plurality of transmitting units, where each of said transmitting units is communicating with a corresponding one of a plurality of receiving stations via the same digital radio channel, each of said plurality of transmitting units and receiving stations having a transmitter and a receiver, said method comprising the steps of:
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(a) performing for each one of said plurality of transmitting units the steps of; (i) calculating a signal path gain between the transmitting unit and the corresponding receiving station; (ii) measuring a co-channel interference power level at the corresponding receiving station; (iii) calculating the product of the reciprocal of said signal path gain, said co-channel interference power level, and a pre-fixed value which corresponds to a minimum target value of the ratio of a received carrier power and a co-channel interference power; and (iv) regulating the power of signals transmitted by the transmitting unit according to the value of said product; and (b) repeatedly performing the steps (i), (ii), (iii) and (iv) with respect to each one of said plurality of transmitting units in an asynchronous manner. - View Dependent Claims (9, 10, 11, 12, 13, 14, 15, 16, 17, 18)
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19. A cellular radio system arranged for distributed power control and using a duplex radio channel having first and second frequency bands, said cellular radio system comprising:
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a first transceiver comprising; (a) a receiver for receiving radio signals transmitted in said first frequency band; (b) a transmitter for transmitting radio signals in said second frequency band; (c) an antenna having an antenna gain; and (d) co-channel interference power level circuitry for measuring a co-channel interference power level at the receiver of said first transceiver; a second transceiver comprising; (a) a receiver for receiving radio signals transmitted in said second frequency band; (b) a transmitter for transmitting radio signals in said first frequency band; (c) a memory unit for storing power control data; (d) a clock mechanism; and (e) an antenna; means for calculating a signal path gain for a signal transmitted from said second transceiver to said first transceiver; and means for calculating the product of (i) the reciprocal of said signal path gain, (ii) said co-channel interference power level, and (iii) a pre-fixed value which corresponds to a minimum target value of the ratio of a received carrier power and a co-channel interference power; and wherein said second transceiver further comprises transmission power control circuitry for regulating, according to said product, the power of signals transmitted by the transmitter in said second transceiver at a rate determined by said clock mechanism. - View Dependent Claims (20, 21, 22)
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23. In a digital mobile radio system, a method of regulating the power of signals transmitted by a plurality of transmitting units, where each of said transmitting units is communicating with a corresponding one of a plurality of receiving stations via the same digital radio channel, each of said plurality of transmitting units and receiving stations having a transmitter and a receiver, said method of comprising the steps of:
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(a) performing for each one of said pluralaity of transmitting units the steps of; (i) calculating a signal path gain between the transmitting unit and the corresponding receiving station; (ii) measuring a co-channel interference power level at the corresponding receiving station; (iii) calculating the product of the reciprocal of said signal path gain, said co-channel interference power level, and a pre-fixed value which corresponds to a minimum target value of the ratio of a received carrier power and a co-channel interference power; and (iv) regulating the power of signals transmitted by the transmitting unit according to the value of said product; and (b) repeatedly performing the steps (i), (ii), (iii) and (iv) with respect to each one of said plurality of transmitting units in a manner not requiring synchrony or coordination among the plurality of transmitting units.
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Specification