Portable radio power control device and method using incrementally degraded received signals

摘要

A portable radio having a transmitter power controller connected to the portable radio's receiver and transmitter for controlling the power transmission level of the portable radio, resulting in reduced power consumption by the portable radio and extended battery life. The transmitter power controller estimates the signal strength and quality of the down-link signal by determining a threshold adjustment parameter for the received signal. Thus, this invention eliminates false power adjustment caused by the interfering signals when RSSI (Received Signal Strength Level) is used as a means to estimate transmitter power level. The threshold adjustment parameter is an adjustment parameter used in adjusting the received signal to produce a degraded signal having a predetermined signal quality, and is determined by incrementally adjusting the received signal until the degraded signal is determined to have the predetermined signal quality. The received signal is adjusted in one embodiment by adding noise to the received signal and in another embodiment by adjusting the bias voltage of an RF amplifier and IF amplifier in the receiver. The threshold adjustment parameter corresponds to the signal strength and quality of the received signal, and a look-up table approach is used in determining and adjusting the power transmission level for the portable radio.