Method and system for time interleaved analog-to-digital converter timing mismatch estimation and compensation
Methods and systems for time interleaved analog-to-digital converter timing mismatch calibration and compensation may include receiving an analog signal on a chip, converting the analog signal to a digital signal utilizing a time interleaved analog-to-digital-converter (ADC), and reducing a blocker signal that is generated by timing offsets in the time interleaved ADC by estimating complex coupling coefficients between a desired digital output signal and the blocker signal utilizing a decorrelation algorithm on frequencies within a desired frequency bandwidth. The decorrelation algorithm may comprise a symmetric adaptive decorrelation algorithm. The received analog signal may be generated by a calibration tone generator on the chip. An aliased signal may be summed with an output signal from a multiplier. The complex coupling coefficients may be determined utilizing the decorrelation algorithm on the summed signals. A multiplier may be configured to cancel the blocker signal utilizing the determined complex coupling coefficients.
1. A method for wireless communication, the method comprising:
receiving an analog signal on a chip;
converting the analog signal to a digital signal utilizing a time interleaved analog-to-digital-converter (ADC); and
reducing a blocker signal that is interfering with a desired digital signal in said time interleaved ADC, based on complex coupling coefficients between said desired digital signal and said blocker signal estimated utilizing a decorrelation algorithm in timing offset estimation and compensation circuitry.
2. The method according to claim 1 , wherein the decorrelation algorithm comprises a symmetric adaptive decorrelation algorithm.
3. The method according to claim 1 , comprising approximating an amplitude of said blocker signal as linear within said desired frequency bandwidth.
4. The method according to claim 1 , comprising performing a foreground estimation and timing offset compensation by generating the received analog signal utilizing a calibration tone generator on said chip.
5. The method according to claim 1 , comprising performing a background estimation and timing offset compensation utilizing an analog signal received from external to said chip.
6. The method according to claim 5 , comprising estimating a change in said timing offset utilizing the background estimation and compensation.
7. The method according to claim 1 , comprising summing the blocker signal with an output signal from a multiplier.
8. The method according to claim 7 , comprising determining said complex coupling coefficients utilizing said decorrelation algorithm on said summed signals.
9. The method according to claim 8 , comprising determining a timing offset in said time interleaved ADC utilizing said determined complex coupling coefficients.
10. The method according to claim 9 , comprising configuring said multiplier with a value determined from said determined timing offset.
11. The method according to claim 1 , comprising cancelling said blocker signal utilizing the configured multiplier.
12. The method according to claim 1 , wherein said time interleaved ADC comprises two ADC paths with clock signals 180 degree phase difference.
13. The method according to claim 1 , comprising estimating a timing offset in said time interleaved ADC based on a ratio of amplitudes of a desired analog signal associated with said desired digital signal and an analog signal associated with the blocker signal.
14. The method according to claim 1 , comprising estimating a timing mismatch for a plurality of frequency channels utilizing said timing offset estimation and compensation circuitry.
15. A system for wireless communication, the system comprising:
one or more circuits on a chip comprising a time interleaved analog-to-digital-converter (ADC), wherein said one or more circuits are operable to:
receiving an analog signal on said chip;
converting the analog signal to a digital signal utilizing said time interleaved ADC; and
reducing a blocker signal interfering with a desired signal in said time interleaved ADC, based on complex coupling coefficients between said desired digital output signal and said blocker signal estimated utilizing a decorrelation algorithm on frequencies within a desired frequency bandwidth.
16. The system according to claim 15 , wherein the decorrelation algorithm comprises a symmetric adaptive decorrelation algorithm.
17. The system according to claim 15 , wherein said one or more circuits are operable to approximate an amplitude of said blocker signal as linear within said desired frequency bandwidth.
18. The system according to claim 15 , wherein said one or more circuits are operable to perform a foreground estimation and timing offset compensation by generating the received analog signal utilizing a calibration tone generator on said chip.
19. The system according to claim 15 , wherein said one or more circuits are operable to perform a background estimation and timing offset compensation utilizing an analog signal received from external to said chip.
20. The system according to claim 19 , wherein said one or more circuits are operable to estimate a change in said timing offset utilizing the background estimation and compensation.