数字域校正零中频发射机镜频干扰和载漏的方法研究

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40dB以上，提高了信噪比。

Research of Compensating Zero-IF Modulator Image Frequency Interference and LO-leakage in the Digital Domainand LO-leakage in the Digital Domain

Considering the zero-IF transmitter existing mirror frequency interference and local oscillator leak, which cause in-band interference, 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. This paper proposes that the basic method of adaptive compensation and the loop delay estimation when the output signals are closed-loop. Finally, the residual mirror signals and carrier leakage signals are over 40dB lower than the effective sideband signals through physical implementation validation by using open-loop method, which have improved SNR.