US 5,056,109 A · Method and apparatus for controlling transmission power in a CDMA cellular mobile telephone system

Abstract

A power control system for a cellular mobile telephone system in which system users communicate information signals between one another via at least one cell site using code division multiple access spread spectrum communication signals. The power control system controls transmission signal power for each cellular mobile telephone in the cellular mobile telephone system wherein each cellular mobile telephone has an antenna, transmitter and receiver and each cell-site also has an antenna, transmitter and receiver. Cell-site transmitted signal power is measured as received at the mobile unit. Transmitter power is adjusted at the mobile unit in an opposite manner with respect to increases and decreases in received signal power. A power control feedback scheme may also be utilized. At the cell-site communicating with the mobile unit, the mobile unit transmitted power is measured as received at the cell-site. A command signal is generated at the cell-site and transmitted to the mobile unit for further adjusting mobile unit transmitter power corresponding to deviations in the cell site received signal power. The feedback scheme is used to further adjust the mobile unit transmitter power so as to arrive at the cell-site at a desired power level.

Claims27

Dependent claims

In a cellular mobile telephone system in which system users communicate information signals between one another via at least one cell-site using code division multiple access (CDMA) spread spectrum communication signals, a power control system for controlling transmission signal power for each mobile telephone in said cellular mobile telephone system, wherein each mobile telephone has an antenna, transmitter and receiver, and each cell-site has an antenna, at least one transmitter and at least one receiver, said power control system comprising:

at least one first power measurement means, each coupled to a respective mobile telephone receiver, for measuring signal power in CDMA communication signals received by said respective mobile telephone receiver;
at least one first power adjustment means, each coupled to a respective mobile telephone receiver and corresponding first power measurement means, said first power adjustment means responsive to decreases and increases in power measurements of said corresponding first power measurement means with respect to a first predetermined power level, for respectively increasing and decreasing transmission signal power of said corresponding mobile telephone transmitter;
at least one second power measurement means, each coupled to a respective cell-site receiver, for measuring signal power in each CDMA communication signal directed to said respective cell-site receiver from a corresponding mobile telephone transmitter in communication therewith;
at least one power adjustment command generator means, each coupled to a respective cell-site transmitter and corresponding second power measurement means, for generating power adjustment commands corresponding to deviations in power measurements of said corresponding second power measurement means from a second predetermined power level, said respective cell-site transmitter transmitting said power adjustment commands;
and
at least one second power adjustment means, each coupled to a respective mobile telephone receiver and corresponding transmitter, said second power adjustment means responsive to said power adjustment commands directed to said respective mobile telephone receiver, for adjusting transmission signal power of said corresponding mobile telephone transmitter.

3 more elements

An apparatus for controlling transmission signal power in a cellular mobile telephone in communications with at least one cell-site station using code division multiple access (CDMA) spread spectrum communication signals, said cellular mobile telephone having an antenna coupled to a transmitter and a receiver, said transmitter for generating and transmitting a CDMA carrier signal according to an assigned spreading function modulated by a mobile user input information signal, said receiver for receiving CDMA communication signals and spectrum processing said received CDMA communication signals according to an assigned spreading function so as to recover a mobile user output information signal intended for a user of said cellular mobile telephone, said cell-site station communicating power control commands in CDMA communication signals intended for said cellular mobile telephone with said receiver providing an output of said power control commands, said apparatus comprising:

measurement means for, operatively coupled to said receiver, measuring combined signal power in contemporaneously received CDMA communication signals and providing a measurement signal indicative of measured signal power;
adjustment means for, operatively coupling to said transmitter, receiving said measurement signal, varying transmitter signal power in opposite correspondence to variations in measured signal power about a predetermined power level;
and
additional adjustment means for, operatively coupled to said receiver and transmitter, receiving said power adjustment commands, and varying transmitter signal power in correspondence thereto.

1 more element

In a cellular mobile telephone system in which system users communicate information signals between one another via at least one cell-site using code division multiple access (CDMA) spread spectrum communication signals, a method for controlling transmission signal power for each mobile telephone in said cellular mobile telephone system, wherein each mobile telephone has an antenna, transmitter and receiver, and each cell-site has an antenna, at least one transmitter and at least one receiver, said method comprising the steps of:

measuring signal power in CDMA communication signals received by each respective mobile telephone receiver;
varying transmission signal power of each corresponding mobile telephone transmitter in inverse proportion to variations in corresponding mobile telephone power measurements with respect to a first predetermined power level;
measuring signal power in each CDMA communication signal received at each respective cell-site receiver as transmitted from a corresponding mobile telephone transmitter in communication therewith;
generating power adjustment commands corresponding to deviations in corresponding cell-site power measurements from a second predetermined power level;
transmitting said power adjustment commands along with said information signals rom each respective cell-site to a corresponding mobile telephone in communication therewith;
receiving at each respective mobile telephone receiver said power adjustment commands corresponding thereto;
and
adjusting transmission signal power of each corresponding mobile telephone transmitter in correspondence to said power adjustment commands directed to said respective mobile telephone receiver.

5 more elements

A method for controlling transmission signal power in a cellular mobile telephone in communications with at least one cell-site station using code division multiple access (CDMA) spread spectrum communication signals, said cellular mobile telephone having an antenna coupled to a transmitter and a receiver, said transmitter for generating and transmitting a CDMA carrier signal according to an assigned spreading function modulated by a mobile user input information signal, said receiver for receiving CDMA communication signals and spectrum processing said received CDMA communication signals according to an assigned spreading function so as to recover a mobile user output information signal intended for a user of said cellular mobile telephone, said cell-site station communicating power control commands in CDMA communication signals intended for said cellular mobile telephone with said receiver processing said received power control commands and providing an output of said power control commands, said method comprising the steps of:

measuring combined signal power in contemporaneously received CDMA communication signals;
varying transmitter signal power in inverse proportion to variations in measured signal power about a predetermined power level;
and
varying transmitter signal power in correspondence to received power adjustment commands.

1 more element

Dependencies are inferred from the claim text.

Method and apparatus for controlling transmission power in a CDMA cellular mobile telephone system

Life of this patent

Method and apparatus for controlling transmission power in a CDMA cellular mobile telephone system

Life of this patent

Abstract

Claims27