宽带接收机前端非线性的盲辨识与数字后补偿方法

摘要

提出了一种基于Volterra模型的实时非线性数字后补偿方法.考虑到接收机难以事先获知输入信号的特点,设计了"大信号频率外总功率最小"的盲辨识准则,自适应地调整模型参数以拟合出与接收机非线性失真特性互逆的传递函数.对多频与16QAM调制输入信号的实测结果表明,该方法可使工作于非线性区的高效率接收前端的无杂散失真动态范围(SFDR)提升近26dB,并大幅提高了对微弱信号的检测能力.%A novel real-time digital nonlinearity post-calibration method was developed based on the Volterra series. With rnthe purpose of fitting the inverse transfer function of the nonlinear distortion characteristics of the receiver, parameters of rnthe model were measured and self-adaptively updated without knowledge of the inputs using the blind identification crirnterion that was aimed at the minimizing of the total energy of the frequencies other than strong signals in the calibrated rnoutputs. Experimental results on multi-tone excitation and 16-QAM modulation input show that with the proposed rnmethod, spurs-free-dynamic-range(SFDR) of the high efficiency nonlinear receiver front-end would achieve almost 26dB rnimprovement, and the ability of the system in weak signals detection can be also significantly enhanced.