Digital automatic gain control method and device for use in communication terminal of mobile radio communication system

A digital automatic gain control method for use in a transmitting/receiving terminal of a mobile radio communication system including a transmission power amplifier and a reception amplifier whose gains are digitally controlled, comprising the steps of:

• generating a transmission gain control signal of a next frame based on transmission power level control information included in a signal received from a base station;
• generating a plurality of timing signals for digitally controlling gains of said transmission power amplifier and said reception amplifier;
• detecting a received signal strength indication of a received reception frame;
• converting said received signal strength indication into a digitalized received signal strength indication signal in response to one of said timing signals;
• mapping said transmission gain control signal into a transmission gain control code;
• mapping the digitalized received signal strength indication signal into a reception gain control code;
• selecting one of said transmission gain control code and said reception gain control code, in response to a number of said timing signals according to one of a transmission mode and a reception mode;
• generating transmission timing control signals and reception timing control signals in response to a second number of said plurality of timing signals;
• latching said transmission gain control code for output to control said gain of said transmission power amplifier in response to said transmission timing control signals and said reception timing control signals during said transmission mode;
• and
• latching said reception gain control code for output to control said gain of said reception power amplifier in response to said transmission timing control signals and said reception timing control signals during said reception mode.

A digital automatic gain control device for variably controlling gain of a transmission power amplifier and a reception power amplifier in a transmitting/receiving terminal of a mobile radio, comprising:

• a control processor for generating a digital transmission gain control signal of a next transmission frame based on transmission power level control information transmitted from a base station and for generating a plurality of timing signals;
• a received signal strength indication detector for detecting a received signal strength indication from said received reception frame;
• an analog-to-digital converter for convelting said received signal strength indication into a digital received signal strength indication signal based on a sampling clock signal generated from said control processor;
• a transmission gain control code mapping device for mapping said digital transmission gain control signal into a transmission gain control code;
• a reception gain control code mapping device for mapping said digital received signal strength indication signal into a reception gain control code;
• a multiplexer for selecting one of said transmission gain control code and said reception gain control code in response to a selection control signal;
• a selection controller for generating said selection control signal based on a combination of a first number of said timing signals and a multiplexing control clock signal generated from said control processor;
• a timing controller for generating transmission and reception timing control signals in response to a second number of said timing signals generated from said control processor;
• a transmission data latch for receiving said transmission gain control code output by said multiplexer and for providing said transmission gain control code to a gain control terminal of said transmission power amplifier in response to said transmission and reception timing, control signals;
• and
• a reception data latch for receiving said reception gain control code from said multiplexer and for providing said reception gain control code to a gain control terminal of said reception power amplifier in response to said transmission and reception timing control signals.