Joint Estimation of Spreading Codes and Information Sequences for Asynchronous Long Code DS-CDMA Signals Based on Sequential Monte Carlo
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摘要: 针对多径信道环境下非同步长码DS-CDMA信号扩频码及信息序列等参数的联合估计问题，该文提出了基于序贯蒙特卡罗(SMC)的盲估计算法。该算法采用混合重要密度函数对联合后验分布模型进行抽样，并迭代计算重要性权值，以完成所需状态参量的估计。同时为了减少算法的计算量，在算法的实现过程中，先估计出各用户的扩频码，再对观测数据进行处理，从而修正原有的迭代步骤，提出一种修正的SMC算法。仿真结果验证了算法对多种情况的适应性，且在时变的多径信道环境下也能获得较好的估计性能。Abstract: To deal with the problem of joint estimation of spreading codes and information sequences for asynchronous long code DS-CDMA signals in multipath channels, an algorithm is introduced based on Sequential Monte Carlo(SMC) for blind estimation. The proposed algorithm emploies hybrid important sampling density to draw the samples from joint posterior distribution iteratively, and computes the importance weight to complete the estimation of the state variable. During the realization of the algorithm, in order to reduce the computational complexity, the modified algorithm estimates the spreading code of each user firstly, then processes the observation data, thereby modifies the original iteration step. Simulation results verify the adaptability of the proposed algorithms for multiple conditions. Moreover, it can obtain good estimation performance in time varying multipath channels.
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WANG Shuai, AN Sining, MIAO Xiaqing, et al. Compressed sensing assisted joint channel estimation and detection for DS-CDMA uplink[J]. IEEE Communications Letters, 2015, 19(10): 1730–1733. doi: 10.1109/LCOMM.2015.2439036 KOIVISTO T and KOIVUNEN V. Blind despreading of short-code DS-CDMA signals in asynchronous multi-user systems[J]. Signal Processing, 2007, 87(11): 2560–2568. doi: 10.1016/j.sigpro.2007.04.012 BUI D M and LEE S. Fast Gaussian process regression for multiuser detection in DS-CDMA[J]. IEEE Communications Letters, 2017, 21(2): 406–409. doi: 10.1109/LCOMM.2016.2620430 LIANG Jianghai, WANG Xiang, WANG Fenghua, et al. Blind spreading sequence estimation algorithm for long-code DS-CDMA signals in asynchronous multi-user systems[J]. IET Signal Processing, 2017, 11(6): 704–710. doi: 10.1049/iet-spr.2016.0506 MASMOUDI A, BELLILI F, AFFES S, et al. Maximum likelihood time delay estimation from single- and multi-carrier DSSS multipath MIMO transmissions for future 5G networks[J]. IEEE Transactions on Wireless Communications, 2017, 16(8): 4851–4865. doi: 10.1109/TWC.2017.2701796 陆凤波. 复杂电磁环境下的欠定盲源分离技术研究[D]. [博士论文], 国防科学技术大学, 2011.LU Fengbo. Research on underdetermiend blind source separation in complex electromagnetic environment[D]. [Ph.D. dissertation], National University of Defense Technology, 2011. SHOREH M H, BEYRANVAND H, and SALEHI J A. Performance evaluation of asynchronous multi-carrier code division multiple access for next-generation long-reach fibre optic access networks[J]. IET Optoelectronics, 2015, 9(6): 325–332. doi: 10.1049/iet-opt.2014.0092 YU Qian, BI Guoan, and ZHANG Liren. Blind multiuser detection for long code multipath DS-CDMA systems with Bayesian MC techniques[J]. Wireless Personal Communications, 2006, 39(3): 265–278. doi: 10.1007/s11277-006-9018-9 YU Qian, BI Guoan, and ZHANG Liren. Modified SMC method of blind multiuser detection for DS-CDMA systems over fading channels[J]. Wireless Personal Communications, 2007, 43(4): 1339–1349. doi: 10.1007/s11277-007-9306-z 钟兆根, 张立民, 林洪文. 基于SMC的STBC-MC-CDMA信号扩频码及信息序列盲估计[J]. 电子学报, 2016, 44(5): 1025–1031. doi: 10.3969/j.issn.0372-2112.2016.05.003ZHONG Zhaogen, ZHANG Limin, and LIN Hongwen. Blind estimation of spreading codes and information sequences for STBC-MC-CDMA signals based on SMC[J]. Acta Electronica Sinica, 2016, 44(5): 1025–1031. doi: 10.3969/j.issn.0372-2112.2016.05.003 SHEN Bin and WANG Jianxin. Chip rate and pseudo-noise sequence estimation for direct sequence spread spectrum signals[J]. IET Signal Processing, 2017, 11(6): 727–733. doi: 10.1049/iet-spr.2016.0687 GU Xiaowei, ZHAO Zhijin, and SHEN Lei. Blind estimation of pseudo-random codes in periodic long code direct sequence spread spectrum signals[J]. IET Communications, 2016, 10(11): 1273–1281. doi: 10.1049/iet-com.2015.0374 GUAN Mingxiang and WANG Le. A novel recognition method for low SNR DSSS signals based on four-order cumulant and eigenvalue analysis[J]. Chinese Journal of Electronics, 2015, 24(3): 650–653. doi: 10.1049/cje.2015.07.036 赵知劲, 李淼, 尚俊娜. 基于矩阵填充和三阶相关的长短码DS-CDMA信号多伪码盲估计[J]. 电子与信息学报, 2016, 38(7): 1788–1793. doi: 10.11999/JEIT151087ZHAO Zhijin, LI Miao, and SHANG Junna. Blind estimation of LSC-DS-CDMA signal based on matrix completion and triple correlation[J]. Journal of Electronics &Information Technology, 2016, 38(7): 1788–1793. doi: 10.11999/JEIT151087 张天骐, 杨凯, 赵亮, 等. 多径衰落信道下MC-CDMA信号扩频序列周期盲估计[J]. 系统工程与电子技术, 2017, 39(12): 2803–2809. doi: 10.3969/j.issn.1001-506X.2017.12.25ZHANG Tianqi, YANG Kai, ZHAO Liang, et al. Blind estimation of spread spectrum sequence period for MC-CDMA signals in multipath fading channels[J]. Systems Engineering and Electronics, 2017, 39(12): 2803–2809. doi: 10.3969/j.issn.1001-506X.2017.12.25 BALASINGAM B. Computationally efficient blind-adaptive algorithms for multi-antenna systems[D]. [Ph.D. dissertation], McMaster University, 2007. -
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