基于小波包函数的正交MC-CDMA及其性能

Performance of Orthogonal Multicarrier CDMA Based on Wavelet Packet Functions

:本文将小波包变换理论应用于多载波码分多址 (MC CDMA)系统 ,提出一种基于小波包函数的正交调制方法 .系统中 ,发端数据串并转换成若干子信道 ,每个子信道的数据进行直序扩频 ,不同子信道上的数据以chip调制不同的小波包函数作为基带传输波形 .小波包函数的一系列优良性质 ,使系统能有效地抗多径干扰 ,抑制子信道串扰、多址干扰等 .本文对系统在多径Rayleigh慢衰落信道中的性能 ,进行了理论分析和计算机仿真 .结果表明 ,本系统比基于DFT的MC CDMA有较大的性能改善 .

A new scheme of orthogonal multicarrier CDMA based on wavelet packet functions is proposed in this paper. Transmitted data bits are converted to a number of parallel sub channels through a serial/parallel converter. On each sub channel each bit is spread by a PN code. Each chip on different sub channel modulates different wavelet packet functions. Good properties of wavelet packet functions ensure that the system can suppress multipath interference, inter subchannel interference(ICI) and multiple access interference(MAI) effectively. The system performance is investigated for a multipath, slow Rayleigh fading channel. The performance advantages of the system over that based on DFT are demonstrated by both analytical and simulation methods.