Patent ID: 7522550

Claim:
An automatic control system of a mobile terminal for time division duplex (TDD) based communication system, comprising: a RF processing module to control quality of a transmission channel; and a baseband modem to generate automatic control signals based on control information received from a base station and to transmit the automatic control signals across a transmission data line to the RF processing module while the mobile terminal is in a reception mode, the baseband modem further to transmit transmission data across the transmission data line to the RF processing module while the mobile terminal is in the transmission mode, wherein the RF processing module includes: a transmission/reception unit to process the data received through an antenna of the mobile terminal so as to transmit the data to the baseband modem, and the transmission/reception unit to process the transmission data received from the baseband modem across the transmission data line so as to transmit the transmission data in the air through the antenna, an oscillator to generate an oscillating frequency, and a switch to receive the automatic control signals from the transmission data line and to check a type of the automatic control signals received across the transmission data line from the baseband modem while the mobile terminal is in the reception mode, and the switch to route the automatic control signal to the transmission/reception unit when the received automatic control signal is an automatic power control (APC) signal or an automatic gain control (AGC) signal and the switch to route the automatic control signal to the oscillator when the received automatic control signal is an automatic frequency control (AFC) signal, wherein the APC, AGC, and AFC signals are transmitted to the RF processing module across the transmission data line.