AUTOMATIC GAIN CONTROL FOR WIRELESS RECEIVER

摘要

PROBLEM TO BE SOLVED: To provide techniques for performing an automatic gain control (AGC) at a wireless receiver. SOLUTION: The total gain for a wireless receiver is achieved with discrete gain steps for analog circuitry and continuous gain for a digital variable gain amplifier (DVGA) 230. An AGC loop is updated based on power measurements for an output signal from the DVGA. A first gain for the analog circuitry is selected from multiple discrete gain values based on the AGC loop to maintain the average power of a baseband signal within a predetermined range at an analog-to-digital converter (ADC) 220 input. A second gain for the DVGA is selected based on the AGC loop to maintain the average power of the output signal at a reference power level. The first gain is switched in a manner to avoid saturation of the ADC caused by the baseband signal and to provide switching hysteresis. The AGC may be performed in log domain and with multiple modes. COPYRIGHT: (C)2011,JPO&INPIT