基于压缩量化的非正弦时域正交调制信号预失真方法

 针对基于椭圆球面波函数的非正弦时域正交调制信号峰均功率比较高，因而受功率放大器非线性失真影响较大的问题，该文设计了一种基于波形训练的非迭代查询表预失真结构。由于所选量化方法直接决定了查询表预失真器的精度，通过分析调制信号的幅值分布特性，提出一种综合考虑功率放大器特性及信号幅值分布特性的压缩量化方法。对采用所提预失真方法前后信号的带内带外失真特性进行了仿真，并与采用幅度均匀量化方式的性能进行了比较。结果表明，该文方法有效改善了非正弦时域正交调制信号功率谱及系统误码率特性，减小了功率放大器给信号带来的非线性失真。

Predistortion Algorithm Based on Compressing Quantization for Nonsinusoidal Orthogonal Modulation Signal in Time-domain

Nonsinusoidal orthogonal modulation signal in time-domain has high peak-to-average power ratio, so it is vulnerable to the nonlinearity of power amplifier. To relieve this affection, a non-iterative look-up table predistortion method based on waveform training is presented which can obtain the amplitude and phase modification value fast and corretly. For the reason that the predistortion accuracy is directly associated with the chosen quantization method, a compressing quantization method is presented. The characteristic of power amplifier and the distribution characteristic of signal amplitude are taken considered in this method. The distortion characteristic in band and out of band of signal before and after imploying the presented predistortion method is simulated and compared with the method with equal space. The results show that the presented method can effectively improve the power spectrum of the signal and the bit error rate performance of system, and minish the intermodulated power of signal.