Clocking scheme in nonlinear systems for distortion improvement
View Patent ↗Systems and methods are provided for clocking scheme to reduce nonlinear distortion. An example system may comprise at least two processing paths, each comprising at least one circuit exhibiting nonlinear behavior. Nonlinearity may be managed during processing of signals, such as by assessing effects of the nonlinear behavior during the processing of signals, and controlling clocking applied via at least one path based on the assessed effects, to reduce the effects of the nonlinear behavior during the processing of signals, eliminating the need for post-processing corrections. The controlling of clocking may comprise adjusting timing of a clock applied in the at least path, such as by introducing a timing-delay adjustment to a clock when the clock is applied to a circuit after the circuit exhibiting nonlinear behavior. A timing-advancement may be applied to signals processed via the at least one path, particularly before the circuit exhibiting nonlinear behavior.
1. A method comprising:
managing nonlinearity in a transceiver, wherein the transceiver comprises at least two separate processing paths for use when processing signals, and each processing path comprises at least one circuit exhibiting nonlinear behavior during said processing of signals, said managing of nonlinearity comprising:
assessing effects of said nonlinear behavior during said processing of signals; and
controlling clocking applied via at least one processing path used during said processing of signals, based on said assessed effects;
wherein:
said controlling of clocking is configured to reduce said effects of said nonlinear behavior during said processing of signals;
said controlling of clocking comprises adjusting timing of a clock applied in said at least one processing path; and
said adjusting of timing of said clock comprises introducing a timing-delay adjustment to said clock when said clock is applied to at least one circuit that follows said least one circuit exhibiting nonlinear behavior.
2. The method of claim 1 , comprising introducing a timing-advancement adjustment to signals processed in said at least one processing path.
3. The method of claim 2 , comprising introducing said timing-advancement adjustment before said least one circuit exhibiting nonlinear behavior.
4. The method of claim 1 , wherein said at least two separate processing paths comprise an in-phase (I) path and a quadrature (Q) path; and said processing of signals comprises processing I and Q components of processed signals.
5. The method of claim 1 , wherein said effects comprise effects of undesired tones or signals introduced because of said nonlinear behavior.
6. The method of claim 5 , wherein said undesired tones or signals comprise one or both of spurious components corresponding to processed signals and fold-back counterparts of said spurious components.
7. A system comprising:
a first processing path that comprises at least one nonlinear circuit that exhibits nonlinear behavior and one or more other circuits;
a second processing path that comprises at least one nonlinear circuit that exhibits nonlinear behavior; and
one or more circuits configured for managing nonlinearity during processing of signals in said system, wherein said one or more circuits are operable to:
assess effects of said nonlinear behavior during said processing of signals; and
control clocking applied via one or both of said first processing path and said second processing path based on said assessed effects;
wherein:
said controlling of clocking is configured to reduce said effects of said nonlinear behavior during said processing of signals; and
at least one of said first processing path and said second processing path comprises a timing circuit operable to introduce, in conjunction with said controlling of clocking, a timing-advancement adjustment to processed signals.
8. The system of claim 7 , wherein:
one of said first processing path and said second processing path comprises an in-phase (I) path operable to process I-components of processed signals; and
another one of said first processing path and said second processing path comprises a quadrature (Q) path operable to process Q-components of processed signals.
9. The system of claim 7 , wherein said at least one nonlinear circuit, in each of said first processing path and said second processing path, comprises a digital-to-analog (DAC) circuit or a sample-and-hold (SAH) circuit.
10. The system of claim 7 , wherein said one or more circuits, in each of said first processing path and said second processing path, comprise a sampler circuit.
11. The system of claim 7 , wherein said one or more circuits, in each of said first processing path and said second processing path, comprise a phase-shifter circuit.
12. The system of claim 7 , wherein said timing circuit precedes said least one nonlinear circuit exhibiting nonlinear behavior.
13. The system of claim 7 , wherein said controlling of clocking comprises adjusting timing of a clock applied in said one or both of said first processing path and said second processing path.
14. The system of claim 13 , wherein said adjusting of timing of said clock comprises introducing a timing-delay adjustment to said clock when applied to one or more circuits that follows said least one circuit exhibiting nonlinear behavior.
15. The system of claim 7 , comprising at least one combining circuit for combining outputs of said first processing path and said second processing path.
16. The system of claim 7 , wherein said effects comprise effects of undesired tones or signals introduced because of said nonlinear behavior.
17. The system of claim 16 , wherein said undesired tones or signals comprise one or both of spurious components corresponding to processed signals and fold-back counterparts of said spurious components.
18. A system comprising:
a first processing path that comprises at least one nonlinear circuit that exhibits nonlinear behavior and one or more other circuits;
a second processing path that comprises at least one nonlinear circuit that exhibits nonlinear behavior; and
one or more circuits configured for managing nonlinearity during processing of signals in said system, wherein said one or more circuits are operable to:
assess effects of said nonlinear behavior during said processing of signals; and
control clocking applied via one or both of said first processing path and said second processing path based on said assessed effects;
wherein:
said controlling of clocking is configured to reduce said effects of said nonlinear behavior during said processing of signals;
said controlling of clocking comprises adjusting timing of a clock applied in said one or both of said first processing path and said second processing path; and
said adjusting of timing of said clock comprises introducing a timing-delay adjustment to said clock when applied to one or more circuits that follows said least one circuit exhibiting nonlinear behavior.
19. The system of claim 18 , wherein:
one of said first processing path and said second processing path comprises an in-phase (I) path operable to process I-components of processed signals; and
another one of said first processing path and said second processing path comprises a quadrature (Q) path operable to process Q-components of processed signals.
20. The system of claim 18 , wherein said at least one nonlinear circuit, in each of said first processing path and said second processing path, comprises a digital-to-analog (DAC) circuit or a sample-and-hold (SAH) circuit.
21. The system of claim 18 , wherein said one or more circuits, in each of said first processing path and said second processing path, comprise a sampler circuit.
22. The system of claim 18 , wherein said one or more circuits, in each of said first processing path and said second processing path, comprise a phase-shifter circuit.
23. The system of claim 18 , comprising at least one combining circuit for combining outputs of said first processing path and said second processing path.
24. The system of claim 18 , wherein said effects comprise effects of undesired tones or signals introduced because of said nonlinear behavior.
25. The system of claim 24 , wherein said undesired tones or signals comprise one or both of spurious components corresponding to processed signals and fold-back counterparts of said spurious components.