However, the distortion resulting from nonlinearity, such as harmonic distortion and inter-modulation distortion, will affect the performance of the entire system. 但是非线性产生的失真,如谐波失真、互调失真(IMD)等将会严重影响系统的整体性能。
From simulation results, the third-order inter-modulation distortion ratio ( IMD3 ) can be reduced by-10 dB on average when a two-tone signal is input. Finally, the bias-controlled predistorter has been used in OFDM system. 从仿真结果可以总结出,当系统采用双音信号作为输入时,功率放大器输出的三阶互调失真(IMD)可以平均减少10dB。最后,将二极管偏压控制预失真器应用于OFDM系统中。
However, a major drawback of OFDM technology is its high Peak-to-Average Power Ratio ( PAPR ), which makes the inter-modulation distortion and severely deteriorates the performance of systems. 然而,OFDM系统中有一个固有的缺点就是信号存在很大的峰均功率比,容易导致OFDM信号的交调失真和系统性能的下降。