采用小波变换的OFDMA系统误码性能分析

BER performance analysis of Wavelet transform based OFDMA

针对LTE下行链路,建立一种基于小波变换的OFDMA(Wavelet Transform based Orthogonal Frequency Division Multiple Access,W-OFDMA)系统,克服频偏和相位噪声带来的不良影响,提升系统的误码性能。将小波作为系统的正交子载波,利用滤波器组的级联形式实现小波变换,取代原系统的快速傅里叶变换。利用Simulink建立W-OFDMA系统基带模型,分析比较高斯信道下基于不同小波的W-OFDMA系统的误码性能,并与传统的OFDMA系统进行比较。仿真结果表明,sym4小波为W-OFDMA系统的最佳子载波,且基于sym4的W-OFDMA系统的误码性能优于传统的OFDMA系统。

Wavelet transform based Orthogonal Frequency Division Multiple Access （W-OFDMA） is proposed to overcome the adverse effects of frequency deviation and phase noise and improve the system＇ s BER performance for LTE downlink. Wavelets are used as orthogonal subcarriers. Fast Fourier Transform is changed by Wavelet Transform which is implemented by multi-level filter banks. The baseband system model of W-OFDMA is built in Simulink. Analysis is carried out using different wavelets under Additive White Gaussian Noise （AWGN） channel and comparisons are conducted with the conventional OFDMA. The simulation results show that sym4 is the most suitable subcarrier for W-OFDMA and the sym4 based W-OFDMA provides better BER performance than the conventional OFDMA.