QPSK信号IQ不平衡的角度统计盲补偿方法

An Angel Statistical Method of Blind IQ Imbalance Compensation for QPSK

针对直接变频接收机四相相移键控( QPSK) 信号的 IQ 不平衡问题,提出了一种角度统计的盲补偿方法。首先利用仿射坐标变换理论建立了实际的 IQ 信号与理想 IQ 信号的坐标旋转以及伸缩关系,然后通过坐标旋转的角度统计方法进行 IQ 不平衡系数的估计,从而实现 QPSK 信号的 IQ 不平衡补偿。仿真实验表明,相比其他的 IQ 不平衡盲补偿算法,该方法在降低误码率( BER) 的同时,减少了计算复杂度。

In this paper,the IQ imbalance of Quadrature Phase Shift Keying （QPSK） signals in the direct- conversion architecture is considered. A blind IQ imbalanced compensation method with angle statistical is proposed. The relationship between the ideal IQ signals and the actual IQ signals is firstly established based on the affine coordinate transformation theory. Then, the IQ imbalance coefficient can be estimated by an angle statistical method in order to compensate the IQ imbalance. The simulation results show that the new method has lower complexity and is able to reduce the Bit Error Rate （BER） compared effectively with other blind IQ imbalance compensation algorithm.