Low-Complexity I/Q Imbalance Calibration Algorithm Based on Zero-IF Receiver

Although the scheme of designing transceiver with zero-IF architecture reduces the design cost, complexity and power loss of the system, this architecture is more sensitive to the I/Q mismatch problem existing in the analog front-end and it is difficult to eliminate the image interference caused by the mismatch. Therefore, a fast and low-cost I/Q imbalance calibration algorithm is needed. As for the problem of I/Q imbalance in zero-IF receiver, a blind estimation algorithm for extracting the calibration parameters and signal compensation is proposed because of the complexity of calculation and hardware circuit, as well as the power consumption of resources under the traditional algorithm. Based on the statistical property of the signal, this algorithm has the specific characteristics of low computational complexity and being easy to implement in hardware circuit. Due to different ideas of parameters extraction, a special calibration model is designed. The result of simulation shows that the proposed algorithm has not only better performance in compensation parameters estimation, but also better calibration performance than the traditional algorithm. By comparing the calibration performance in the case of different gain imbalances or phase imbalances, we can see that the algorithm can maintain a good calibration performance under different imbalance conditions.