数字预失真系统反馈通道增益平坦度的补偿

摘要

The gain flatness of feedback chain is a key feature in a WCDMA<E mixed mode base-station Radio Remote Head (RRH). The flatness is measured using CW without destroying the integrality of the analog chains. The gains of RF, LO and IF are calculated separately with least squares curve fitting algorithm. The coefficients of compensation filter are generated using MATLAB tools. The flatness of IF is compensated offline in DPD software with little additional complexity. The method works well in practical system.%针对数字预失真系统对反馈链路平坦度的要求，提出一种在不断开模拟链路的前提下，采用单音测量WCD．MA＆LTE混模基站射频拉远单元反馈链路的增益平坦度，并采用最小二乘法，分别拟合射频、本振和中频的增益的方法。采用MATLAB工具产生滤波器系数，在基本不增加复杂度的基础上，通过DPD软件离线补偿中频的增益不平坦度。实际应用取得良好的补偿效果。