基于加权分数傅立叶变换的混合载波码分多址多天线系统

Hybrid carrier CDMA multi-antenna system based on weighted-type fractional Fourier transform

为实现与现有码分多址(CDMA)多天线系统的兼容,提出了一种基于加权分数傅立叶变换的混合载波CDMA多天线系统。本系统在某阶分数傅立叶变换域上采用CDMA技术对发送信号进行序列扩展,对扩展后的信号进行空时分组编码后将信号映射到对应的天线端口上去。通过选择特定的参数,本系统可以转换为单载波或多载波CDMA多天线系统。同时,本系统与现有的单载波和多载波系统相比,信号能量分布更为均匀,从而可以有效地抵抗信道衰落,取得更优的系统误码性能。

This paper proposes a hybrid carrier Code Division Multiple Access （CDMA） multi-antenna system based on weighted-type fractional Fourier transform to improve the compatibility of existing systems. In this system, CDMA technique is applied in a certain fractional Fourier transform domain, and the signals after spreading are coded by space-time block coding and mapped to the corresponding antenna ports. The proposed system can switch single carrier or multi-carrier CDMA multi-antenna system under specific selected condition. Moreover, the signal energy distribution of the hybrid carrier system is more uniform compared to the single carrier or multi-carrier system, which can resist channel fading effectively, resulting in better system performance.