Digital automatic gain control method and device

An automatic gain control device comprising:

• a peak detector configured to receive a current output of an ADC and compare it to a previous output to produce a peak value;
• an out-of-range indicator configured to receive an out-of-range signal if an input to the ADC exceeds the dynamic range of the ADC, the out-of-range indicator operable to increase the peak value if the out-of-range indicator receives the out-of range signal;
• an error detector coupled to the out-of-range indicator and the peak detector and operable to produce an error level, the error level the difference of an output of the out-of-range indicator and a pre-selected target value, the pre-selected target value chosen to attenuate interference signals that exceed the dynamic range of the ADC but minimize the attenuation of communication signals;
• an integrator coupled to the error detector and configured to sum the error level with an integrator value to determine a new integrator value;
• and
• a quantizer coupled to the integrator and operable to receive the new integrator value and determine a new level of attenuation.

A receiver for receiving two or more communication channels in the presence of interference, the receiver comprising:

• an antenna operable to receive an analog signal comprising two or more communication channels;
• an analog to digital converter coupled to the antenna and configured to sample the analog signal and to convert the analog signal into a digital representation;
• an attenuator coupled to the antenna and configured to attenuate the analog signal prior to the analog-to-digital converter sampling the analog signal;
• and,
• an automatic gain control coupled to the output of the analog to digital converter and an input of the attenuator, the automatic gain control comprising:
• a peak detector configured to receive a current output of an ADC and compare it to a previous output to produce a peak value;
• an out-of-range indicator configured to receive an out-of-range signal if an input to the ADC exceeds the dynamic range of the ADC, the out-of-range indicator operable to increase the peak value if the out-of-range indicator receives the out-of range signal;
• an error detector coupled to the out-of-range indicator and operable to produce an error level, the error level the difference of an output of the out-of-range indicator and a pre-selected target value chosen to attenuate interference signals that exceed the dynamic range of the ADC but minimize the attenuation of communication signals;
• an integrator coupled to the error detector and configured to sum the error level with an integrator value to determine a new integrator value;
• and
• a quantizer coupled to the integrator and operable to receive the new integrator value and determine a new level of attenuation.