Composite analog to digital receiver with adaptive self-linearization
View Patent ↗A distortion correcting analog to digital converter (ADC) system includes a plurality of ADCs configured to convert an analog signal to a plurality of digital ADC outputs, wherein the plurality of ADCs are configured to generate a composite signal based on the plurality of ADC outputs, there is an offset between a first one of the plurality of ADC outputs and a second one of the plurality of ADC outputs, the offset causing distortion in the composite signal. The system further includes an adaptive self-linearizer configured to receive the composite signal, and to perform self-linearization based on the composite signal to correct for the distortion in the composite signal. Generating a distortion corrected digital signal includes converting an analog signal to a plurality of digital signals; generating a composite signal based on the plurality of digital signals; wherein there is an offset between a first one of the plurality of ADC outputs and a second one of the plurality of ADC outputs, the offset causing distortion in the composite signal. The method further includes sending the composite signal to an adaptive self-linearizer and performing self-linearization based on the composite signal to correct for distortion in the composite signal.
1. A distortion correcting analog to digital converter (ADC) system, comprising:
a plurality of ADCs configured to convert an analog signal to a plurality of digital ADC outputs, wherein:
the plurality of ADCs are configured to generate a composite signal based on the plurality of ADC outputs;
there is an offset between a first one of the plurality of ADC outputs and a second one of the plurality of ADC outputs, the offset causing distortion in the composite signal; and
an adaptive self-linearizer configured to receive the composite signal, and to perform self-linearization based on the composite signal to correct for the distortion in the composite signal, wherein
performing self-linearization includes:
adaptively generating a replica distortion signal that is substantially similar to the distorted component; and
subtracting the replica distortion signal from the composite signal to obtain an output signal.
2. The system of claim 1 , wherein the offset includes a phase offset.
3. The system of claim 1 , wherein the offset includes an amplitude offset.
4. The system of claim 1 , wherein the adaptive self-linearizer includes a persistence filter configured to generate a linearly enhanced signal based on the composite signal.
5. The system of claim 4 , wherein the adaptive self-linearizer includes a subtractor configured to subtract the linearly enhanced signal from the composite signal to generate a target signal.
6. The system of claim 4 , wherein the adaptive self-linearizer includes a mirror modulator configured to modulate the enhanced signal with a mirroring sequence.
7. The system of claim 6 , wherein the mirror modulator generates a reference signal, and the adaptive self-linearizer further includes an adaptive filter configured to filter the reference signal.
8. The system of claim 7 , wherein the adaptive filter is configured to adapt a filter coefficient.
9. The system of claim 8 , wherein the filter coefficient is duplicated on a second filter.
10. The system of claim 8 , wherein the adaptive filter is configured to adapt the filter coefficient, based at least in part on a difference between the target signal and the filtered signal.
11. A method of generating a distortion corrected digital signal, comprising:
converting an analog signal to a plurality of digital signals;
generating a composite signal based on the plurality of digital signals; wherein there is an offset between a first one of the plurality of ADC outputs and a second one of the plurality of ADC outputs, the offset causing distortion in the composite signal;
sending the composite signal to an adaptive self-linearizer; and
performing self-linearization based on the composite signal to correct for distortion in the composite signal, including:
adaptively generating a replica distortion signal that is substantially similar to the distorted component; and
subtracting the replica distortion signal from the composite signal to obtain an output signal.
12. The method of claim 11 , wherein performing self-linearization includes generating a linearly enhanced signal based on the composite signal.
13. The method of claim 12 , wherein performing self-linearization includes subtracting the linearly enhanced signal from the composite signal to generate a target signal.
14. The method of claim 12 , wherein performing self-linearization includes modulating the enhanced signal with a mirroring sequence.
15. The method of claim 14 , wherein modulating the enhanced signal with a mirroring sequence generates a reference signal, and wherein performing self-linearization further includes filtering the reference signal using an adaptive filter to generate a filtered signal.
16. The method of claim 15 , wherein performing self-linearization includes adapting a filter coefficient of the adaptive filter.
17. The method of claim 16 , further comprising duplicating the filter coefficient on a second filter.
18. The method of claim 16 , wherein the adaptive filter is configured to adapt the filter coefficient, based at least in part on a difference between the target signal and the filtered signal.
19. An adaptive self-linearizer, comprising:
an interface configured to receive a composite signal that is a combination of a plurality of analog to digital converter (ADC) outputs, wherein there is an offset between a first one of the plurality of ADC outputs and a second one of the plurality of ADC outputs, the offset causing distortion in the composite signal; and
an adaptive self-linearization module configured to receive the composite signal, and to perform self-linearization based on the composite signal to correct for the distortion in the composite signal; wherein
performing self-linearization includes:
adaptively generating a replica distortion signal that is substantially similar to the distorted component; and
subtracting the replica distortion signal from the composite signal to obtain an output signal.
20. A method of generating a distortion corrected digital signal, comprising:
receiving a composite signal that is a combination of a plurality of analog to digital converter (ADC) outputs, wherein there is an offset between a first one of the plurality of ADC outputs and a second one of the plurality of ADC outputs, the offset causing distortion in the composite signal; and
performing self-linearization based on the composite signal to correct for the distortion in the composite signal; wherein
performing self-linearization includes:
adaptively generating a replica distortion signal that is substantially similar to the distorted component; and
subtracting the replica distortion signal from the composite signal to obtain an output signal.