Signal processor for a radio receiver

A signal processor for a radio receiver, the signal processor comprising:

• a signal input configured to receive a signal;
• an output;
• an interference synthesizer having a first synthesizer input coupled to the signal input, a second synthesizer input configured to receive a spectral repetition interval value of an interferer signal, and a synthesizer output, and configured to generate an interference reference signal from the spectral repetition interval value and the received signal, to output the interference reference signal on the synthesizer output, and to generate the interference reference signal by applying a frequency-to-time transform to the modified extended interference reference model, the interference synthesizer comprising:
• a fast fourier transform, FFT, module having an FFT input coupled to the first synthesizer input a FFT magnitude output and a FFT phase output;
• a reshaper module having a reshaper output, a first reshaper input coupled to the second synthesizer input, and a second reshaper input coupled to the FFT magnitude output, and configured to receive a signal frequency magnitude spectrum on the second reshaper input, split the received signal frequency magnitude spectrum into a plurality of frames, each frame having a number of frequency bins dependent on the spectral repetition interval of the interferer signal, each frequency bin having a magnitude value, normalize the magnitude value of each frequency bin in each frame, and output the normalized plurality of frames;
• an analyser module having a first analyser output, a second analyser output, and an analyser input coupled to the reshaper output, and configured to output an interference model frame determined from the plurality of frames on the first analyser output and an expected variability of each bin in the interference model frame on the second analyser output;
• a replicator module having a replicator output, and a replicator input coupled to the first analyser output and configured to generate an extended interference reference model by replicating the interference model frame and de-normalizing each replicated interference model frame;
• and
• a combiner module having a first combiner input coupled to the FFT magnitude output, a second combiner input coupled to the second analyser output, a third combiner input coupled to the replicator output, and a combiner output coupled to the synthesizer output, and configured to compare the frequency bins of the extended interference reference model and the frequency bins of the received signal spectrum to determine which frequency bins include interference, and generate the interference reference signal from the frequency bins in the received signal spectrum including interference;
• and
• wherein the spectral repetition interval value based on a frequency domain period of repeating interference patterns, and wherein the signal processor is configured to adapt the received signal dependent on the interference reference signal and to provide the adapted received signal to the output.