摘要
为了克服功率放大器的非线性特性导致的带内失真和临道干扰对通信系统性能的影响,提出了一种基于多项式拟合的自适应预失真技术。该方法根据输入和输出的一些采样数据,依据某种算法或原则,用有限项多项式近似表示预失真器的非线性函数,能够很好的实现功放的线性化。通过对双音信号和16QAM基带信号进行仿真,该方法能够有效改善双音信号的三阶互调分量,降低16QAM调制信号通过放大器后星座图的畸变度,使通信系统的系统性能整体提高。
In order to overcome the influence of in-of-band distortion and adjacent-channel interference to communication system because of nonlinearity of PA, this article presents a adaptive predistortion based on polynomial-fitting, which use limit terms polynomial to fit nonlinearity function of predistortioner by some arithmetic or principle and some sample dates of input and output, achieving perfect linearity performance of PA. Through simulation of a double-tone signal and 16QAM basic signal, it prove that this way can improve third-order intermodulation efficiently and rectify the misshapen constellation shape after 16QAM modulation signal passing amplifier directly, improving the whole system performance.
出处
《电子质量》
2008年第10期18-21,共4页
Electronics Quality
关键词
功率放大器
预失真
多项式拟合
三阶互调
power amplifier
predistorfion
polynomial-fitting
third-order intermoduiation
