摘要
基于子带变换理论构建的广义正交传输复用模型,不仅适用于TDMA、FDMA和CDMA多用户系统,也适用于像OFDM之类的多载波(MC)系统以及由OFDM与CDMA综合而成的MC-CDMA系统。该模型在结构上等效于均匀DFT滤波器组,可以采用FFT结合多相滤波器组的方式高效实现。本文实现的多载波系统具有子载波间隔可伸缩性特点,而复杂性与OFDM加窗处理相接近。在相同仿真环境下得到的结果表明:基于软脉冲响应的多载波系统(MCSIS)误码率性能优于OFDM;对于相同衰落信道,MC-CDMA系统抗衰落特性明显优于OFDM。
Based on subband transformation theory, a general model for orthogonal transmultiplexers is constructed. Besides several popular multiuser communication applications such as TDMA, FDMA and CDMA, it can also describe multi-carrier systems such as OFDM and multi-carrier CDMA system, the combination of MC modulation and CDMA. The model, whose structure is equivalent to DFT filterbanks, can be efficiently realized with the help of FFT and polyphase filterbanks. MC system realized in this paper allows the variation of the subcarrier spacing with a fine granularity and its complexity is comparable to the one of OFDM with windowing. The simulation results of MCSIS (a kind of MC system with soft impulse shaping ) show that its performance is better than the one of OFDM on the same condition. MC-CDMA performs better than OFDM thanks to its built-in robustness against frequency-selective fading.
出处
《通信学报》
EI
CSCD
北大核心
2002年第12期102-109,共8页
Journal on Communications
基金
国家高技术发展计划(863)基金资助项目(2002AA712034)
广东省自然科学基金资助项目(20001641)
