基于OFDM的DFT加扰矢量码分多址接入技术

doi:10.3969/j.issn.0258-2724.2017.01.021

周杲^1,2,
范平志^1,2,,,
郝莉^1,2

基金项目:

国家自然科学基金资助项目（61032002，60872014）

高校学科创新引智计划资助项目（111工程）（111-2-14）

瑞典科学与技术合作项目（2008DFA12160）

详细信息

作者简介:
周杲(1973-),女,讲师,硕士,研究方向为无线频率复用与多址接入,E-mail:gzhou@home.swjtu.edu.cn

通讯作者:
范平志(1955-),男,教授,博士,博士生导师,研究方向为编码理论与无线通信,E-mail:p.fan@ieee.org

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出版历程
- 收稿日期:2015-09-28
- 刊出日期:2017-02-25

OFDM based DFT Scrambling Vector Code Division Multiple Access

ZHOU Gao^1,2,
FAN Pingzhi^1,2,,,
HAO Li^1,2

摘要

摘要:为解决基于多载波的多址系统在出现子载波深度衰落时系统性能下降的问题，根据矩阵置换原理，提出了一种DFT加扰矢量多载波码分多址接入系统（DFT-VMC-CDMA）.该系统利用张量积（Kronecker积）的矩阵分解性，引入矢量正交频分复用（V-OFDM）技术对发射信号进行组合排列，通过对张量积的矩阵向量求解获得分集增益抑制单一子载波上的衰落，并基于r循环信道矩阵的分解特性，加入DFT扩展和加扰前缀，减小系统复杂度和峰平比.通过仿真验证可知，该系统性能与传统的多载波系统相比，在20 dB高信噪比条件下，比上行链路的多载波直接序列码分多址（MC-DS-CDMA）平均提升6 dB，比下行链路的多载波码分多址（MC-CDMA）平均提升0.5 dB，达到了理论上的多径信道分集增益界；此外，新系统还降低了峰平比，提升了频谱效率，如当载波数为64，块长为8，保护间隔为12时，峰平比降低了2 dB，频谱效率提升了10%.
- 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
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 pre-scrambling 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 signal-to-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 0.5 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.
- V-OFDM/
- MC-DS-CDMA/
- MC-CDMA

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参考文献 (16)

KOZEK W, MOLISCH A F. Non-orthogonal pulse shapes for multicarrier communication in doubly dispersive channels[J]. IEEE Journal on Selected Areas in Communications, 1998, 16(8):1579-1589.

SIOHAN P, SICLET C, LACAILLE N. Analysis and design of OFDM/OQAM systems based on filterbank theory[J]. IEEE Trans. on Signal Processing, 2002, 50(5):1170-1183.

LIU Tingting, YANG Chenyang. Equivalent signal-alignment-based frequency-domain equalization for MC-CDMA two-way relay systems[J]. IEEE Trans. on Vehicular Technology, 2012, 61(1):237-248.

DEVELI I, AKDAGLI A, Approximate expression of bit error rate in uplink MC-CDMA systems with equal gain combining[J]. Journal of Communications and Networks, 2013, 15(1):25-30.

AHMED J, HAMDI K A. Spectral efficiency of asynchronous MC-CDMA with frequency offset over correlated fading[J]. IEEE Trans. on Vehicular Technology, 2013, 62(7):3423-3429.

LIU Zilong, GUAN Yongliang, UDAYA P. New complete complementary codes for peak-to-mean power control in multi-carrier CDMA[J]. IEEE Trans.on Communications, 2014, 62(3):1105-1113.

NIKOPOUR H, BALIGH H. Sparse code multiple access[C]//2013 IEEE 24th International Symposium on Personal Indoor and Mobile Radio Communications (PIMRC). London:IEEE, 2003:332-336.

LU Lei, CHEN Yan, GUO Wenting, et al. Prototype for 5G new air interface technology SCMA and performance evaluation[J]. China Communications, 2015, 12:38-48.

XIA Xianggen. Precoded and vector OFDM robust to channel spectral nulls and with reduced cyclic prefix length in single transmit antenna systems[J]. IEEE Trans. on Communications, 2001, 49(8):1363-1374.

HAN Chenggao, HASHIMOTO T, SUEHIRO N. Constellation-rotated vector OFDM and its performance analysis over rayleigh fading channels[J]. IEEE Trans. on Wireless Communications, 2010, 58(3):828-838.

ZHOU Gao, FAN Pingzhi, HAO Li, et al. DFT scrambling vector OFDM and its performance analysis[C]//2011 Third International Conference on Communications and Mobile Computing (CMC). Qingdao:IEEE, 2011:381-384.

YEE N, LINNARTZ J P, FETTWEIS G. Multi-carrier CDMA in indoor wireless radio networks[C]//IEEE PIMRC'93. Yokohama:IEEE, 1993:109-103.

DASILVA V, SOUSA E S. Performance of orthogonal CDMA codes for quasi-synchronous communication systems[C]//IEEE International Conference on Universal Personal Communications (ICUPC'93). Ottawa:IEEE, 1993:995-999.

SUEHIRO N, JIN Rongzhen. Performance of very efficient wireless frequency usage system using kronecker product with rows of DFT matrix[C]//Proceedings of 2006 IEEE Information Theory Workshop (ITW'06). Chengdu:IEEE, 2006:526-529.

PROAKIS J G. Digital communication[M]. 3nd ed.[S.l.]:McGraw-Hill Companies, 1995:758-840.

VAN R N, DE W A. Reducing the peak-to-average power ratio of OFDM[C]//IEEE Vehicular Technology Conf(VTC'98).[S.l.]:IEEE, 1998, 2072-2076.

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