数字域校正零中频发射机IQ不平衡的研究  

Research of Compensating Zero-IF Modulator IQ Imbalance in Digital Domain

作　　者：邹世源[1] 刘久文[1] 阳辉[2] 

机构地区：[1]北京航空航天大学电子信息工程学院,北京100191 [2]清华大学信息技术研究院,北京100084

出　　处：《电视技术》2013年第23期163-166,共4页Video Engineering

摘　　要：考虑到零中频发射机存在的镜频干扰和本振泄露会产生带内干扰,分析了同相正交信号(IQ)的非理想特性,给出了易于硬件实现的校正方法。当输出射频信号开环时,提出在数字域中建立查找表和校正IQ不平衡的操作方法;当射频信号闭环时,提出自适应补偿的基本方法和环路时延估计,并给出了仿真方法。最后,通过运用开环校正物理实现验证,残留镜像和载漏信号均比有效边带信号低40 dB以上,提高了信噪比。Considering the zero-IF transmitter existing mirror frequency interference and local oscillator leak, which cause in-band mterference, the non-ideal characteristics of the in-phase and quadrature signals （IQ） are analyzed. It is given that the correction methods are easily implemented in hardware. It is proposed that establishment of the lookup table in the digital domain and the operation method of correcting IQ imbalance when the output signals are open-loop. The basic method of adaptive compensation and the loop delay estimation when the output signals are closed-loop are proposed. Finally, the residual mirror signals and cartier leakage signals are over 40 dB lower than the effective sideband signals through physical implementation validation by using open-loop method, which have improved SNR.

关 键 词：零中频 数字域 镜频干扰 本振泄露 

分 类 号：TN949.6[电子电信—信号与信息处理]