基于极坐标的自适应数字预失真器  

On Adaptive Digital Pre-distortion Device Based On Polar Coordinates

作　　者：李林[1,2] 艳鹏 

机构地区：[1]重庆电子工程职业学院,重庆401331 [2]重庆大学通信工程学院,重庆400044 [3]河南信息统计职业学院,郑州450000

出　　处：《西南师范大学学报（自然科学版）》2015年第8期75-78,共4页Journal of Southwest China Normal University(Natural Science Edition)

基　　金：重庆市教委科学技术研究项目(KJ102201);国家自然科学基金项目(60872038)

摘　　要：基于极坐标方式,以Taylor级数拟合预失真器的AM/AM和AM/PM特性曲线,输入信号幅度作为索引信号创建幅度与相位并联的两张查找表,运用最小均方自适应算法更新表项系数来补偿功放的非线性,设计了自适应数字预失真器.通过Matlab搭建了基于16-QAM调制解调的自适应数字预失真系统.仿真结果表明,邻近通道功率比降低近20dB,功放的线性度得到了明显改善.Taylor series is used to fit the AM/AM and AM/PM characteristic curves of the pre‐distortion device .Two look‐up tables （amplitude table and phase table） are created by means of the amplitude of the input signal in polar coordinates .T he nonlinearity of the pow er amplifier is compensated by updating the coefficients of the table through least mean square adaptive algorithm .According to the method mentioned above ,An adaptive digital pre‐distortion system based on 16‐QAM modulation and demodulation is built through the Matlab software .The simulation results show that adjacent channel power ratio （ACPR） is reduced about 20dB .The linearity of power amplifier is significantly improved .

关 键 词：极坐标 TAYLOR级数 查找表 Saleh模型 邻近通道功率比 

分 类 号：TN722[电子电信—电路与系统]