一种基于模糊辨识的OFDM系统预失真器设计

将有记忆的高功率放大器(HPA)描述成一个线性动态系统级联一个无记忆非线性系统的Wiener系统模型,由Sugeno模糊模型自适应跟踪HPA的无记忆非线性曲线,通过离线过程设计OFDM系统数字预失真器。为了消除HPA记忆效应,首先在频域得到信号的均衡补偿,然后通过傅里叶逆变换后得到时域记忆性补偿。该预失真器具有收敛速度快、系统稳定、补偿效果好的特点。

Design of a Predistorter Based on Fuzzy Identification in OFDM Systems

The nonlinear high power amplifier (HPA) with memory is modeled as a Wiener system by a linear dynamic subsystem followed by a zero-memory nonlinear subsystem. The predistorter is designed in an offline process using the Sugeno fuzzy model. For compensating the memory effect, the signal compensation in frequency domain is firstly got,and then the time domain compensation is obtained by the inverse Fourier transform. Simulation results show that the predistorter converges fast and stably and effectively reduces the effect of nonlinear distortion.