Mirror signal iq-imbalance correction
AssigneeSiTune Corporation
InventorsSaeid Mehrmanesh, Vahid M. Toosi, Mahdi Khoshgard
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Abstract
A system and method are provided for calibrating the IQ-imbalance in a low-IF receiver. A Test Signal can be generated in a mirror frequency and conveyed to the receiver. The power of the signal produced in the receiver from the conveyed Test Signal can be measured. In the absence of an IQ-imbalance, the Test Signal can be completely eliminated in the receiver and the corresponding measured power of the produced signal can be minimized. Accordingly, a two dimensional algorithm is described for calibrating a receiver and correcting the IQ-imbalance by adjusting the phase and gain difference between the I and Q channels in the receiver based on the measured power of the signal produced in the receiver.
Claims20
A system comprising:
- a low-IF receiver configured to be tunable for selected channels;
- a synthesizer configured to produce a Test Signal in mirror frequencies for a selected channel and for conveying the Test Signal to the receiver;
- and
- an IQ Imbalance Estimator configured for estimating a phase imbalance and a gain imbalance in the receiver based on a signal produced in the receiver from the Test Signal.
A method comprising:
- selecting a channel in a low-IF receiver;
- producing a Test Signal in mirror frequencies for the selected channel;
- conveying the Test Signal to the receiver;
- and
- estimating a phase imbalance and a gain imbalance in the receiver based on a signal produced in the receiver from the Test Signal.
An apparatus comprising:
- a low-IF receiver configured to be tunable for selected channels;
- a synthesizer configured to produce a Test Signal in mirror frequencies for a selected channel and for conveying the Test Signal to the receiver;
- a power detector configured to produce a Power Estimate of the signal produced in the receiver from the conveyed Test Signal;
- an IQ Imbalance Estimator configured for estimating a phase imbalance and a gain imbalance in the receiver based on the Power Estimate;
- and,
- an IQ Imbalance Compensator configured for adjusting the difference in the gain and the phase between the I channel and the Q channel in the receiver based on the estimated gain imbalance and the estimated phase imbalance.
Dependencies are inferred from the claim text.