Digital front end for oversampled low-IF or zero-IF multimode receivers
AssigneeSilicon Laboratories Inc.
InventorJavier Elenes
Life of this patent
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Abstract
A digital radio signal is processed by converting an analog signal to a digital signal, decimating the digital signal using a CIC filter and supplying the decimated digital signal directly to an asynchronous sample rate converter (ASRC). The decimated signal is resampled in the ASRC and the ASRC output is supplied directly to a droop compensation filter to compensate the output of the ASRC. By carefully choosing the response of the CIC filter and the resample rate of the ASRC, aliased artifacts in the pass band can be kept below a threshold magnitude without the need for a channelization filter.
Claims22
A method comprising:
- decimating a digital signal generated by an analog to digital converter;
- supplying the decimated digital signal to an asynchronous sample rate converter (ASRC);
- resampling the decimated digital signal in the ASRC to generate a resampled signal;
- and
- droop compensating the resampled signal.
A radio receiver comprising:
- a decimation filter to provide a decimated digital signal;
- an asynchronous sample rate converter (ASCR) coupled to receive the decimated digital signal and resample the decimated digital signal to provide a resampled signal;
- and
- a droop compensator to droop compensate the resampled signal.
A digital radio receiver comprising:
- an analog radio frequency front end to receive a digital radio signal and supply an analog output corresponding to the digital radio signal;
- an oversampled delta sigma analog to digital converter coupled to receive the analog output and supply a digital signal;
- a cascaded integrated comb (CIC) decimation filter coupled to the analog to digital converter to decimate the digital signal to provide a decimated digital signal;
- an asynchronous sample rate converter (ASCR) coupled to receive the output of the CIC decimation filter and resample the decimated digital signal to provide a resampled signal;
- and
- a droop compensation filter to droop compensate the resampled signal.
Dependencies are inferred from the claim text.