US 5,551,057 A · Cellular mobile radio system power control

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.

Claims23

Dependent claims

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.

3 more elements

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:

(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.

5 more elements

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:

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.

14 more elements

Dependencies are inferred from the claim text.

Cellular mobile radio system power control

Life of this patent

Cellular mobile radio system power control

Life of this patent

Abstract

Claims23