Interference dependent ADC headroom adjustment

A method for adjusting the headroom for a received signal in a radio receiver, the received signal including a target signal and an interference signal, the method comprising:

• amplifying the received signal at an amplification level to an amplified signal;
• converting the amplified signal to a digital signal;
• digitally filtering the digital signal at a first interference attenuation factor to produce a first filter output proportional to the magnitude of the interference signal when the interference signal is greater in magnitude than the target signal;
• adjusting the amplification level of the received signal based on the first digital filter output such that the difference between the maximum possible digital signal and the amplified signal is decreased when the interference signal is greater than the target signal;
• and
• digitally filtering the digital signal at a second interference attenuation factor.

A system for adjusting the headroom for a received signal in a radio receiver, the received signal including a target signal and an interference signal, the system comprising:

• an amplification module for amplifying the received signal at an amplification level to an amplified signal;
• a conversion module for converting the amplified signal to a digital signal;
• a first filtering module for digitally filtering the digital signal at a first interference attenuation factor to produce a first filter output proportional to the magnitude of the interference signal when the interference signal is greater in magnitude than the target signal;
• an adjusting module for adjusting the amplification level of the received signal based on the first digital filter output such that the difference between the maximum possible digital signal and the amplified signal is decreased when the interference signal is greater than the target signal;
• and
• a second filtering module for digitally filtering the digital signal at a second interference attenuation factor.