一种用于CDMA系统的正交序列调制方法

An Orthogonal Sequence Modulation for CDMA System

在宽带移动通信系统中，经常考虑采用通过ＦＦＴ实现的多载波调制，如ＯＦＤＭ。本文提出了一种利用ＦＨＴ实现的ＣＤＭＡ系统的正交序列调制方案。其基本思想为利用Ｗａｌｓｈ函数作为载波，将Ｗａｌｓｈ函数分组，从每组中选出一些作为载波，这样不同的载波组合方式本身将包含用户信息。这种方法实现简单，可提高传输效率，并容易与ＣＤＭＡ相结合，能有效地抑制多径干扰。仿真结果表明，该方案在多径衰落信道中能得到很好的性能。

Multicarrier transmission schemes using FFT are often considered for mobile broadband system. The paper presents a new orthogonal sequence modulation sceheme using FHT which is easier to implement than FFT. The basic idea of the scheme is to use Walsh functions as carriers and divide them into several groups, then select some carriers from every group so as to carry user information over carrier's combination pattern. Thus the transmission efficiency is greatly improved. This scheme is easy to cooperate with CDMA and impervious to multipath interference. The simulation results show that the system using such scheme can get good performance in multipath fading channel.