多径信道下UFMC系统的信道估计

doi:10.11959/j.issn.1000-0801.2018113

摘要/Abstract

摘要：

通用滤波多载波（UFMC）技术作为5G的一种候选波形，能够抑制带外辐射、实现宽松同步并且很好地支持物联网中短的突发分组传输。但在 UFMC 传输中不加循环前缀（CP），多径衰落信道下会产生符号间干扰（ISI）以及子载波间干扰（ICI），在信道估计时会影响估计精度。首先分析了多径信道下UFMC系统接收端的干扰情况，在采用反馈均衡抑制ISI后，根据相邻载波间干扰相近的特性，采用自消除算法抑制ICI，并且根据UFMC系统设计导频系数。最后仿真对比了不同多径时延下UFMC系统与CP-OFDM系统信道估计以及误码率性能，通过仿真验证，提出的导频设计方法应用到UFMC中能够很好地抑制干扰，提高估计精度，降低误码率。

关键词: 通用滤波多载波, 符号间干扰, 载波间干扰, 导频设计, 信道估计

Abstract:

As a candidate waveform of 5G,universal filter multi-carrier (UFMC) technology could inhibit out-of-band radiation,achieve loose synchronization and well support the short bursts of things in the transmission.However,in the UFMC transmission without cyclic prefix (CP),inter-symbol interference (ISI) and subcarrier interference (ICI) are generated in the multipath fading channel,which will affect the estimation accuracy in channel estimation.The interference of the UFMC system in multipath channel was firstly analyzed.After using the feedback equalization suppression ISI,the self-elimination algorithm was used to suppress the ICI according to the similarity between adjacent carriers,and the pilot coefficients were designed according to the UFMC system.Finally,the simulation results show that the proposed method applied to the UFMC can suppress the interference,improve the accuracy and reduce the bit error rate.

Key words: UFMC, inter-symbol interference, subcarrier interference, pilot design, channel estimation

中图分类号:

TN919

余翔,高燕妮,段思睿. 多径信道下UFMC系统的信道估计[J]. 电信科学, 2018, 34(4): 22-30.

Xiang YU,Yanni GAO,Sirui DUAN. Channel estimation of UFMC system in multipath channel[J]. Telecommunications Science, 2018, 34(4): 22-30.

图/表 8

图1

图2

图3

图4

表1

图5

图6

图7

参考文献 21

[1]	董振江, 董昊, 韦薇 ,等. 5G 环境下的新业务应用及发展趋势[J]. 电信科学, 2016,32(6): 58-64.
	DONG Z J , DONG H , WEI W ,et al. New services and development trend in 5G environment[J]. Telecommunications Science, 2016,32(6): 58-64.
[2]	倪善金, 赵军辉 . 5G无线通信网络物理层关键技术[J]. 电信科学, 2015,31(12): 48-53.
	NI S J , ZHAO J H . Key technologies in physical layer of 5g wireless communications network[J]. Telecommunications Science, 2015,31(12): 48-53.
[3]	谢显中 . 第 5 代移动通信基本要求与新型多址复用技术[J]. 重庆邮电大学学报（自然科学版）, 2015,27(4): 434-440.
	XIE X Z . Key requirements and multi-access multiplexing techniques for 5G[J]. Journal of Chongqing University of Posts and Telecommunications(Natural Science Edition), 2015,27(4): 434-440.
[4]	FARHANG-BOROUJENY B . OFDM versus filter bank multicarrier[J]. IEEE Signal Processing Magazine, 2011,28(3): 92-112.
[5]	KIBRIA M G , VILLARDI G P , ISHIZU K ,et al. Throughput enhancement of multicarrier cognitive M2M networks:universal-filtered OFDM systems[J]. IEEE Internet of Things Journal, 2016,3(5): 830-838.
[6]	HELWA S S , IBRAHIM M , ELRAMLY S . Universal filtered multi-carrier performance analysis with multipath fading channels[C]// International Conference on Next Generation Mobile Applications,Security and Technologies,Aug 24–26,2016,Cardiff,UK. Piscataway:IEEE Press, 2016: 35-40.
[7]	WANG S , THOMPSON J S , GRANT P M . Closed-form expressions for ICI/ISI in filtered OFDM systems for asynchronous 5G uplink[J]. IEEE Transactions on Communications, 2017,PP(99):1.
[8]	AMO C P D . Iterative joint estimation procedure for channel and frequency offset in multi-antenna OFDM systems with an insufficient cyclic prefix[J]. IEEE Transactions on Vehicular Technology, 2013,62(8): 3653-3662.
[9]	邱昕, 张浩, 亓中瑞 ,等. CP不足情况下OFDM系统信道估计与均衡[J]. 电子科大学报, 2009,38(2): 198-201.
	QIU X , ZHANG H , QI Z R ,et al. On channel estimation and equalization of OFDM systems with insufficient cyclic prefix[J]. Journal of University of Electronic Science and Technology of China, 2009,38(2): 198-201.
[10]	ZHANG L , XIAO P , QUDDUS A . Cyclic prefix-based universal filtered multicarrier system and performance analysis[J]. IEEE Signal Processing Letters, 2016,23(9): 1197-1201.
[11]	PHAM T , LE-NGOC T , WOODWARD G K ,et al. Channel estimation and data detection for insufficient cyclic prefix MIMO-OFDM[J]. IEEE Transactions on Vehicular Technology, 2017,66(6): 4756-4768.
[12]	李俊, 田苑, 邱玉 ,等. 面向5G应用的OQAM-OFDM调制:原理、技术和挑战[J]. 电信科学, 2016,32(6): 15-19.
	LI J , TIAN Y , QIU Y ,et al. Principles,technologies and challenges of OQAM-OFDM for 5G applications[J]. Telecommunications Science, 2016,32(6): 15-19.
[13]	KOFIDIS E , . Channel estimation in filter bank-based multicarrier systems:challenges and solutions[C]// International Symposium on Communications,Control and Signal Processing,May 21-23,2014,Athens,Greece. Piscataway:IEEE Press, 2014: 453-456.
[14]	HU S , WU G , LI T ,et al. Preamble design with ICI cancellation for channel estimation in OFDM/OQAM system[J]. IEICE Transactions on Communications, 2010,E93-B(1): 211-214.
[15]	KANG S , CHANG K . A novel channel estimation scheme for OFDM/OQAM-IOTA system[J]. ETRI Journal, 2007,29(4): 430-436.
[16]	CUI W , QU D , JIANG T ,et al. Coded auxiliary pilots for channel estimation in FBMC-OQAM systems[J]. IEEE Transactions on Vehicular Technology, 2016,65(5): 2936-2946.
[17]	WANG X , WILD T , SCHAICH F ,et al. Pilot-aided channel estimation for universal filtered multi-carrier[C]// Vehicular Technology Conference,Sep 6–9,2015,Boston,USA. Piscataway:IEEE Press, 2016: 1-5.
[18]	WANG X , WILD T , SCHAICH F ,et al. Universal filtered multi-carrier with leakage-based filter optimization[C]// European Wireless Conference 2014,May 14–16,2014,Barcelona,Spain.[S.l.:s.n], 2014: 1-5.
[19]	WANG X , WILD T , SCHAICH F . Filter optimization for carrier-frequency and timing-offset in universal filtered multi-carrier systems[C]// Vehicular Technology Conference,May 11–14,2015,Glasgow,United Kingdom. Piscataway:IEEE Press, 2015: 1-6.
[20]	WEN M , LI Y , CHENG X ,et al. Index modulated OFDM with ICI self-cancellation in underwater acoustic communications[C]// Asilomar Conference on Signals,Systems and Computers,Nov 3–6,2014,Pacific Grove,CA,USA. Piscataway:IEEE Press, 2014: 338-342.
[21]	秦文彭, 启琮 . 利用ICI 自消除改善OFDM系统时变信道估计与均衡的性能[J]. 电子与信息学报, 2008,30(9): 2189-2192.
	QIN W P , QI Z . Performance improvement of time-varing OFDM channel estimation and equalization using ICI serf-cancellation[J]. Journal of Electronics ＆ Information Technology, 2008,30(9): 2189-2192.

仿真项目	参数
FFT点数N	512
实际占用子载波数	120
子载波数/子带	12
子带数	10
OFDM中CP长度	20
均衡方式	频域单抽头
调制方式	QPSK
滤波器	切比雪夫
旁瓣衰减/dB	40
滤波器长度	21