Iq mismatch correction filter
AssigneeTexas Instruments Incorporated
InventorsSthanunathan RAMAKRISHNAN, Chandrasekhar SRIRAM, Raju Kharataram CHAUDHARI
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Abstract
An IQ estimation module comprising a powerup state IQ estimator configured to generate powerup state IQ estimates based on a powerup calibration of the IQ estimation module, a steady state IQ estimator configured to generate steady state IQ estimates during a steady state operation of the IQ estimation module, and an IQ estimate extender configured to determine differences between the powerup state IQ estimates and steady state IQ estimates at their respective frequency bins and adjust the powerup state IQ estimates to improve the accuracy of IQ estimates.
Claims25
An IQ estimation module comprising:
- a powerup state IQ estimator configured to generate powerup state IQ estimates across a frequency band based on a powerup calibration of the IQ estimation module;
- a steady state IQ estimator configured to generate steady state IQ estimates for at least one frequency bin of the frequency band during a steady state operation of the IQ estimation module;
- and
- an IQ estimate extender coupled to the powerup state IQ estimator and the steady state IQ estimator, and configured to compute an actual difference between the powerup state IQ estimates and the steady state IQ estimates, interpolate the actual difference across the frequency band, and adjust the powerup state IQ estimates across the frequency band based on the interpolated difference,
- wherein the actual difference comprises a difference between an estimate of the powerup state IQ estimates at a bin of the at least one frequency bin and an estimate of the steady state IQ estimates at the respective bin.
An IQ signal receiver comprising,
- an amplifier configured to amplify a received passband signal;
- a mixer coupled to the amplifier and configured to mix the amplified passband signal with an in-phase and quadrature components of a local oscillator signal to generate an IQ baseband signals;
- a low pass filter coupled to the mixer and configured to filter noise from the IQ baseband signals;
- an analog digital converter coupled to the low pass filter and configured to convert the IQ baseband signals into IQ digital signals;
- an IQ estimation module coupled to the analog digital converter and configured to generate powerup state IQ estimates across a frequency band based on a powerup calibration of the IQ estimation module, generate steady state IQ estimates for at least one frequency bin of the frequency band during a steady state operation of the IQ estimation module, compute an actual difference between an estimate of the powerup state IQ estimates at a bin of the at least one frequency bin and an estimate of the steady state IQ estimates at the respective bin, interpolate the actual difference across the frequency band, and adjust the powerup state IQ estimates across the frequency band based on the interpolated difference, and
- an IQ mismatch correction module coupled to the IQ estimation module and configured to compensate the IQ digital signals for IQ mismatch based on the adjusted powerup state IQ estimates generated by the IQ estimation module.
An IQ estimation method comprising,
- generating powerup state IQ estimates across a frequency band based on a powerup calibration of an IQ signal receiver;
- generating steady state IQ estimates for at least one frequency bin of the frequency band during a steady state operation of the IQ signal receiver;
- computing an actual difference between an estimate of the powerup state IQ estimates at a bin of the at least one frequency bin and an estimate of the steady state IQ estimates at the respective bin;
- interpolating the actual difference across the frequency band;
- and
- adjusting the powerup state IQ estimates across the frequency band based on the interpolated difference.
Dependencies are inferred from the claim text.