数字接收机I/Q支路不平衡的时域补偿

为了消除数字接收机同相与正交(I/Q)支路幅度和相位不平衡对数字接收机接收性能的影响,根据时域数据I/Q支路的功率与正交关系,提出了一种I/Q支路不平衡参数估计和补偿方法。该方法的估计和补偿均在时域进行,可以在计算复杂度、估计时间和补偿性能三者之间进行折衷;它无需导频或者训练序列,可应用于多种制式的单载波和多载波接收机中。仿真结果表明:利用该方法的64QAM-OFDM系统误码率在AWGN信道下可以达到理想性能,在多径信道下1×10-3误码率处的性能损失可以减小到0.1 dB左右。

Time domain compensation of I/Q imbalance in digital receivers

The performance degradation of digital receivers caused by I/Q gain and phase imbalances is improved by a method to estimate and compensate for I/Q imbalances based on the power and orthogonality relationships between the in-phase and quadrature channels of the time domain data.Both of the estimates and the compensation are carried out in the time domain which allows for a flexible tradeoff between computational complexity,estimation time and compensation performance.Because the estimation of the I/Q imbalance does not need any pilots or training sequence,this technique is applicable to a wide range of single-carrier and/or multi-carrier communication and broadcasting systems.Simulations of a 64QAM-OFDM system show that this technique can achieve the optimal bit error rate(BER) performance under AWGN channel,and can reduce the performance degradation to about 0.1 dB when the BER is 10-3 under frequency-selective fading channel.