Adjusting gain in a receiver using received signal sample values

Abstract

A mobile communication device comprising a handset achieves gain control of a received signal by adjusting gain of the received signal based on A/D converter samples of the received signal, rather than on power I,and Q,calculations of the received signal. The device processes a received signal and adjusts its gain by first setting signal gain to a maximum level, then providing the amplified received signal to an analog-to-digital converter (ADC) that produces a predetermined number of ADC signal sample values in a single cycle of an estimated signal frequency of the received signal. Setting the signal gain to a maximum initial level will cause a number of ADC signal sample values to have full scale magnitude, indicating saturation of the ADC. Next, the device continues processing by determining the number of ADC signal sample values that indicate full scale magnitude of the received signal within a signal cycle, and then adjusts the signal gain from the maximum level that causes the number of ADC signal sample values that indicate full scale magnitude to be above a predetermined saturation threshold so as to reduce the signal gain until the saturation threshold is not exceeded. In this way, a communications device constructed in accordance with the invention provides improved signal gain control and associated processing performance with minimized costs.