IQ imbalance correction method and system of zero intermediate frequency receiver

Abstract

The invention provides an IQ imbalance correction method and system for a zero intermediate frequency receiver; the method comprises the steps: carrying out the IQ imbalance estimation of a received signal during the factory calibration of the receiver, and obtaining a first IQ imbalance parameter; storing the first IQ imbalance parameter in a first register, and carrying out pre-calibration through the parameter stored in the first register; when the receiver is normally used, performing frequency domain IQ imbalance estimation through the frequency domain pilot signal and the signal-to-noise ratio parameter to obtain a second IQ imbalance parameter; and storing the second IQ imbalance parameter to a second register, performing fine calibration through the parameter stored in the second register, and outputting calibrated data. According to the scheme, a large unbalanced parameter is calibrated during factory calibration, a small amount of unbalance degree is remained, and the residual unbalance parameter is compensated when the receiver is in the receiving state, so that the calibration precision of the system is higher, and extra spectrum resource consumption is not increased.

Description

technical field [0001] The invention relates to the technical field of IQ imbalance correction, in particular to an IQ imbalance correction method and system for a zero-IF receiver. Background technique [0002] The zero-IF receiver refers to the receiver that can directly convert the radio frequency signal into the original transmission signal without going through the intermediate frequency. The zero-IF receiver has no image interference and is easy to realize single-chip integration. Ideally, the amplitude and phase information of the modulated IQ signals should match, the amplitude should be the same, and the phase should be 90 degrees different. However, in an actual communication system, due to physical limitations of circuit hardware and inevitable design errors in circuit design, there will be a mismatch between the amplitude and phase of the two signals, that is, IQ imbalance, which will greatly reduce the receiving system. BER performance. [0003] Existing metho...

AI Technical Summary

Problems solved by technology

However, in an actual communication system, due to physical limitations of circuit hardware and inevitable design errors in circuit design, there will be a mismatch between the amplitude and phase of the two signals, that is, IQ imbalance, which will greatly reduce the receiving system. BER performance

[0003] Existing methods for implementing IQ imbalance correction include adaptive compensation based on training sequences and data-based statistical performance. However, adaptive compensation based on training sequences requires a large number of training sequences and wastes spectrum resources; while data-based statistical performance When, for the convenience of calculation, it is generally assumed that there is no imbalance in one of the channels, but in fact, both IQ channels are unbalanced, resulting in low calibration accuracy

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