AUTOMATIC GAIN CONTROL IN A RECEIVER

摘要

Automatic gain control in a receiver. A method for controlling operating range of an analog-to-digital converter (ADC) by an automatic gain control circuit includes estimating a peak-to-average ratio corresponding to an analog signal from digital samples of the analog signal. The method includes determining a peak value corresponding to the analog signal based on the peak-to-average ratio. Further, the method includes maintaining magnitude of the analog signal at an input of the ADC and gain of the receiver based on the peak value.

主权项

1. A receiver comprising:
an analog-to-digital converter (ADC) that converts an analog signal into digital samples; and an automatic gain control circuit coupled to the ADC and responsive to the digital samples to estimate a peak-to-average ratio corresponding to the analog signal, determine a peak value corresponding to the analog signal based on the peak-to-average ratio, and maintain magnitude of the analog signal at an input of the ADC and gain of the receiver based on the peak value, the automatic gain control circuit including:
an estimating unit that estimates the peak-to-average ratio corresponding to the analog signal, the estimating unit including:
a first multiplier that receives the digital samples to generate a first signal having a magnitude equal to square of the digital samples;a first summer coupled to the first multiplier to generate sum of the first signal and a delayed signal;a first delay element coupled to the first summer to generate a second order norm of the digital samples;a second multiplier coupled to the first delay element to generate square of the second order norm; anda first logarithmic element coupled to the second multiplier to generate a logarithmic value of the square of the second order norm; anda determining unit that determines the peak value corresponding to the analog signal based on the peak-to-average ratio.