基于R&S信号源与频谱仪的宽带数字预失真算法研究

Wideband Digital Predistortion Algorithm Validation based on R&S SMW200A and FSW43

本文基于R&S公司SMW200A信号源和FSW43频谱仪验证了提出的宽带数字预失真算法。采用一个64QAM调制、600MHz带宽、峰均比7.0 d B、采样率为1.92GHz的宽带信号去激励一个工作在1.8GHz的AB类功率放大器,在功放接近饱和条件下,利用提出的简化GMP模型进行数字预失真校正,输出信号的EVM指标从8.4%改善到1.4%,满足了线性化要求,同时实验证明了简化的GMP模型有与GMP模型接近的性能,模型系数个数约GMP模型的三分之一。

Thispaperpresents a wideband digital predistortion algorithm and achieves the validation based on R&S SMW200A and FSW43.Using a 64-QAM 600MHz bandwidth signal with 7.0dB PAPR and 1.92GHz sampling rate,the Class AB power amplifier that operated at 1.8GHz was linearized with a novel digital predistortion(DPD)technique based on reduced GMP model.When the operation points were approximately the saturation region,the measured EVM was reduced from 8.4%to 1.4%,meeting the linearity specifications.The experiments also showed that the Reduced GMP model’s performance was closeto GMP model’s and its number ofcoefficientswas nearly onethird of GMP model’s.