传统的基于查找表的数字自适应预失真技术没有考虑功率放大器输入信号的统计特性。为此,在正交频分复用(OFDM)系统中,结合OFDM信号幅度概率分布的特性,提出一种新的查找表构建方法。仿真结果表明,与传统的基于查找表的预失真技术相比,该方法能够有效地抑制由功率放大器非线性特性引起的信号带外频谱扩展。
Traditional Look-up Table(LUT)-based predistortion technology does not take the statistical properties of power amplifier's input into consideration. A new LUT-based digital predistortion technique combined with the statistical properties of amplitude of Orthogonal Frequency Division Multiplexing(OFDM) signal is proposed in OFDM systems. Simulation results show that compared with traditional LUT-based predistortion technology, the new scheme can effectively suppress the spread spectrum that is caused by the nonlinearity of power amplifier.