西南交通大学学报2017，Vol.52Issue(1)：148-155,8.DOI:10.3969/j.issn.0258-2724.2017.01.021
基于OFDM的DFT加扰矢量码分多址接入技术
OFDM based DFT Scrambling Vector Code Division Multiple Access
摘要
Abstract
Channel spectral nulls (or deep fades) on some sub-carriers will degrade the performance of multiple access systems based on multiple access OFDM.To improve the performance,a novel DFT scrambling vector multi-carrier DS-CDMA was proposed based on the theory of matrix permutation.Using the decomposability of tensor product (or named Kronecker product),the new system rearranges the transmission signals with the help of vector OFDM (V-OFDM),uses channel diversity resulted from by matrix vector decomposition of Kronecker product to restrain the single sub-carrier deep fading,and lowers the system complexity and peak-to-average power ratio (PAPR) by DFT spread and prescrambling based on analyzing decomposition characteristics of r-cyclical matrix.Simulation results show that the novel system is better than traditional multi-carrier accesses.For example,at high signalto-noise ratio (Eb/N0),such as 20 dB,compared with a typical uplink access,i.e.,multi-carrier direct-sequence code division multiple access (MC-DS-CDMA),the new system performance is upgraded by 6 dB averagely,and is slightly O.5 dB better than a typical downlink access,multi-carrier code division multiple access (MC-CDMA).It achieves full channel diversity order theoretically.Moreover,the new system lowers PAPR and promotes spectrum efficiency compared with the two traditional accesses.For instance,with 64 sub-carriers,8 blocks and 12 guard intervals,the proposed system reduces PAPR with 2 dB,and gains more 10％ spectrum too.关键词
矢量正交频分复用/多载波直接序列码分多址/多载波码分多址Key words
V-OFDM/MC-DS-CDMA/MC-CDMA分类
信息技术与安全科学引用本文复制引用
周杲,范平志,郝莉..基于OFDM的DFT加扰矢量码分多址接入技术[J].西南交通大学学报,2017,52(1):148-155,8.基金项目
国家自然科学基金资助项目(61032002,60872014) （61032002,60872014）
高校学科创新引智计划资助项目(111工程)(111-2-14) （111工程）
瑞典科学与技术合作项目(2008DFA12160) （2008DFA12160）
