一种新型的宽带接收机IQ矫正结构  

A Novel IQ Correction Structure for Wideband Receivers

作　　者：马雅男 徐卫 刘道煦 邹建 MA Ya-nan;XU Wei;LIU Dao-xu;ZOU Jian(Chengdu Spaceon T&C Technology Co.,Ltd.,Chengdu 611731,China)

机构地区：[1]成都天奥测控技术有限公司,四川成都611731

出　　处：《测控技术》2021年第2期118-122,共5页Measurement & Control Technology

摘　　要：针对零中频接收机射频端失真引发的IQ不平衡现象影响系统性能的问题,提出了一种新型的基于神经网络的盲矫正方案,并利用9361开发平台对窄带单音信号和宽带正交相移键控(QPSK)接收信号进行实验验证。以二阶统计特性的正定性为目标设计补偿公式,并创新地以BP神经网络的动量法为参考推导得到新的迭代算法。实验结果表明,该方法不仅能够在算法迭代次数减少71.43%的基础上,有效地将单音信号的镜像抑制比(IRR)提升50 dB,而且对于宽带QPSK传输系统,其接收信号的误差向量幅度(EVM)降低至未矫正时的21.03%,信噪比(SNR)提升达到13.54 dB。这一结果表明,对于窄带和宽带系统,所提算法针对IQ不平衡效应的补偿都体现出了正确性和高效性,因此利用该方法在不增加训练序列的情况下,能够大大提升系统的性能,为后续零中频接收芯片国产化的发展提供了助力。In order to solve the problem that IQ imbalance of zero-IF receivers RF end distortion affects the system performance,a novel blind correction scheme based on BP neural network is proposed,and the 9361 development platform is used to verify the narrowband single tone signal and the wideband quadrature phase shift keying(QPSK)received signal.Utilizing the second-order statistical characteristic theory of communication signal,the compensation function is derived.According to the momentum method of the BP neural network,a new adaptive iterative algorithm was obtained.The experimental results show that the image rejection ratio(IRR)of the single tone is improved by 50 dB with the number of iterations reduced by 71.32%at the same time.For the wideband QPSK system,compared with the uncorrected signals,the error vector magnitude(EVM)of the received sequences is decreased by 21.03%,and the signal-to-noise ratio(SNR)is increased to 13.54 dB by using this structure.These results reflect that the new structure effectively and accurately reduces the IQ imbalance destruction in narrowband and wideband system.Without increasing the training sequence,this method can greatly improve the system performance and provide assistance for the development of zero-IF receiver chip in China.

关 键 词：IQ不平衡 宽带接收机 二阶统计特性 BP神经网络 

分 类 号：TN929.5[电子电信—通信与信息系统]