Method and system for measuring IQ path mismatch
View Patent ↗Aspects for measuring IQ path mismatch in signal modulation are described. The aspects include estimating a transmitter IQ mismatch in a form of gain and phase response for transmitter I and Q paths sharing a receiver path, and estimating a receiver IQ mismatch in a form of gain and phase response for receiver I and Q paths sharing a signal source. Further included is compensating for the difference of the transmitter and receiver I and Q paths using a digital FIR filter. Iterative estimation is utilized for filter tap parameters during the compensating.
1. A method for measuring IQ path mismatch in transceivers, the method comprising:
estimating a transmitter IQ mismatch in a form of gain and phase response for transmitter in-phase (I) and quadrature (Q) paths sharing a receiver path; and
estimating a receiver IQ mismatch in a form of gain and phase response for receiver I and Q paths sharing a signal source,
wherein the estimating of the transmitter IQ mismatch comprises measuring a difference in the gain and phase response between the transmitter I and Q paths, and the estimating of the receiver IQ mismatch comprises measuring a difference in the gain and phase response between the receiver I and Q paths.
2. The method of claim 1 , wherein the measuring comprises sending a tone signal and measuring a power and phase shift for all of desired frequency points.
3. The method of claim 2 , wherein the measuring comprises sending uniformly spaced multi-tone white signals, taking a fast Fourier transform (FFT) of a unit period of the uniformly spaced multi-tone white signals, and calculating the response from a power and phase of each tone.
4. The method of claim 1 , comprising compensating for the difference of the transmitter and receiver I and Q paths using a digital FIR filter.
5. The method of claim 4 , comprising utilizing iterative estimation for filter tap parameters during the compensating.
6. A system for estimation of IQ path mismatch during signal modulation, the system comprising
a transceiver, the transceiver comprising a transmitter and a receiver; and
a processor coupled to the transceiver, the processor identifying a transmitter IQ mismatch in a form of gain and phase response for transmitter in-phase (I) and quadrature (Q) paths sharing a receiver path, and identifying a receiver IQ mismatch in a form of gain and phase response for receiver I and Q paths sharing a signal source,
wherein the estimating of the transmitter IQ mismatch comprises measuring a difference in the gain and phase response between the transmitter I and Q paths, and the estimating of the receiver IQ mismatch comprises measuring a difference in the gain and phase response between the receiver I and Q paths.
7. The system of claim 6 , wherein the processor sends a tone signal and measures a power and phase shift for all of desired frequency points.
8. The system of claim 7 , wherein the processor sends uniformly spaced multi-tone white signals, taking a fast Fourier transform (FFT) of a unit period of the uniformly spaced multi-tone white signals, and calculating the response from a power and phase of each tone.
9. The system of claim 6 , comprising a digital FIR filter coupled to the transmitter and receiver paths that compensates for the difference of the transmitter and receiver I and Q paths.
10. The system of claim 9 , wherein the processor utilizes iterative estimation for filter tap parameters during the compensating.
11. A method for estimating IQ path mismatch in a transceiver, the method comprising:
measuring a difference in the gain and phase response between transmitter in-phase (I) and quadrature (Q) paths and between receiver I and Q paths of a transceiver, the transmitter I and Q paths sharing a receiver path and the receiver I and Q paths sharing a signal source; and
compensating for the difference of the transmitter and receiver I and Q paths using a digital FIR filter.
12. The method of claim 11 , wherein the measuring comprises sending a tone signal and measuring a power and phase shift for all of desired frequency points.
13. The method of claim 12 , wherein the measuring comprises sending uniformly spaced multi-tone white signals, taking a fast Fourier transform (FFT) of a unit period of the uniformly spaced multi-tone white signals, and calculating the response from a power and phase of each tone.
14. The method of claim 13 , wherein the compensating comprises utilizing iterative estimation for filter tap parameters.
15. The method of claim 14 , comprising performing the measuring and compensating for spectrum efficient modulation.
16. A system for estimation of IQ path mismatch during signal modulation, the system comprising
a processor operatively coupled to a transceiver comprising a transmitter and a receiver, the processor identifying a transmitter IQ mismatch in a form of gain and phase response for transmitter in-phase (I) and quadrature (Q) paths sharing a receiver path, and identifying a receiver IQ mismatch in a form of gain and phase response for receiver I and Q paths sharing a signal source,
wherein the estimating of the transmitter IQ mismatch comprises measuring a difference in the gain and phase response between the transmitter I and Q paths, and the estimating of the receiver IQ mismatch comprises measuring a difference in the gain and phase response between the receiver I and Q paths.
17. The system of claim 16 , wherein the processor sends a tone signal and measures a power and phase shift for all of desired frequency points.
18. The system of claim 17 , wherein the processor sends uniformly spaced multi-tone white signals, taking a fast Fourier transform (FFT) of a unit period of the uniformly spaced multi-tone white signals, and calculating the response from a power and phase of each tone.
19. The system of claim 16 , comprising a digital FIR filter coupled to the transmitter and receiver paths that compensates for the difference of the transmitter and receiver I and Q paths.
20. The system of claim 19 , wherein the processor utilizes iterative estimation for filter tap parameters during the compensating.