摘要
基于多频带正交频分复用超宽带(MB-OFDM-UWB)通信系统,在编码器与串并变换器之间加入一个直接序列扩频器,构建一个直接序列扩频与多级跳频相结合的多址技术.利用直接序列码分多址(DS-CDMA)为用户分配地址,提高了用户容量;同时将用户的一个数据信息扩展到多个码片上,通过多个子载波发送出去,使系统具有频率分集的效果,提高了系统抗窄带干扰和抗频率选择性衰落的性能.仿真结果表明,当误比特率为10-2时,MB-OFDM-UWB多址方案可以改善系统信噪比5 dB左右,性能明显优于TH-PPM多址方案.
On the basis of the multi-band orthogonal frequency division multiplexing ultra-wideband （MB-OFDM-UWB） communication systems, this paper proposed a multiple access technology by adding a direct-sequence spread-spectrum between the encoder and parallel-to-serial （P/S） converter and combining direct-sequence spread-spectrum with multi-stage frequency-hopping. The direct sequence-code division multiple access （DS-CDMA） improves the capacity of the system by distributing access to the users. Besides, the user＇s data are spread to multiple chips and transmitted through multi-sub-carriers so that the system gets the frequency diversity and has better capacity against narrow-band interference and frequency selective fading. The simulation results showed that when the bit error rate （BER） was 10^-2, the scheme proposed had the advantage over TH-PPM multiple access about 5 dB in signal to noise ratio （SNR）.
出处
《南通大学学报（自然科学版）》
CAS
2009年第3期17-20,共4页
Journal of Nantong University(Natural Science Edition)
基金
江苏省高校自然科学研究计划项目(07KJB510091)
南通市应用研究计划项目(K2007014)
关键词
多频带
正交频分复用
超宽带通信
多址接入
multi-band
orthogonal frequency division multiplexing
ultra wideband communications
multiple access
