OFDM系统信道估计技术研究
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摘要
在无线移动信道中,实现高速率和高质量的通信服务,是无线通信的目标和要求。正交频分复用(OFDM)技术具有频谱利用率高、能够有效对抗频率选择性衰落的影响而日渐受到人们的普遍关注。而信道估计技术是实现OFDM可靠传输的关键技术之一,为了在接收端能够正确地解调出发端信息,需要从接收数据中将信道信息准确的估计出来,信道估计的精度将直接影响整个系统的性能。
本文首先分析比较了基于导频类信道估计中的各种算法,在对基于m序列信道估计研究的基础上,从计算复杂度低,估计精度高的角度出发,给出了基于失配序列和序列偶的信道估计方法,并通过计算机仿真与m序列信道估计方法以及传统估计算法中的LS、DFT算法进行了比较。
其次,在对判决反馈信道估计方法研究的基础上,针对传统判决反馈信道估计初始信道估计值不够精确的缺点,给出了m序列、失配序列分别与判决反馈相结合的信道估计方法,利用m序列、失配序列较为精确的估计性能作为初始估计值来进行判决反馈。通过MATLAB仿真,与判决反馈方法、失配序列信道估计方法、m序列信道估计的方法进行比较,仿真结果进一步验证了本文的可行性,并且总结了几种方法的优劣性及可能存在的问题,为进一步的研究提供了方向。
In the wireless mobile channel, to realize high speed and high quality service is the target and requirement of wireless communications. Orthogonal Frequency Division Multiplexing has attracted much attention for its high spectrum efficiency and strong immunity to frequency selective fading availably. Nevertheless, channel estimation is one of the key technologies for reliable transmission in OFDM system. In order to correctly demodulate information from sending terminal, it is therefore needed to estimate channel information accurately from receiving data. The accuracy of channel estimation will directly affect the performance of the whole system.
Firstly, this text analyzes some kinds of algorithms based on channel estimation using pilot symbols. Based on research of channel estimation applying m-sequence, using the mismatched sequence and sequence pairs channel estimation algorithm has been put forward in the circumstances of low complexity and higher accuracy. It compared with applying m-sequence and traditional algorithm by computer simulation.
Secondly, based on decision feedback channel estimation, this text directed towards the shortcoming of inaccuracy on traditional decision feedback. It put forward new algorithm that uses mismatched sequence or m-sequence to combine decision feedback respectively. Using the mismatch sequence and m-sequence could accurately estimate performance as the initial estimate for decision feedback. It is compared with applying mismatch sequence channel estimation and m-sequence channel estimation and decision feedback channel estimation. The result of simulation by MATLAB verified the feasibility of the paper. It summarized disadvantage and advantage about seveval methods, and provided the direction of the further research aspects.
本文首先分析比较了基于导频类信道估计中的各种算法,在对基于m序列信道估计研究的基础上,从计算复杂度低,估计精度高的角度出发,给出了基于失配序列和序列偶的信道估计方法,并通过计算机仿真与m序列信道估计方法以及传统估计算法中的LS、DFT算法进行了比较。
其次,在对判决反馈信道估计方法研究的基础上,针对传统判决反馈信道估计初始信道估计值不够精确的缺点,给出了m序列、失配序列分别与判决反馈相结合的信道估计方法,利用m序列、失配序列较为精确的估计性能作为初始估计值来进行判决反馈。通过MATLAB仿真,与判决反馈方法、失配序列信道估计方法、m序列信道估计的方法进行比较,仿真结果进一步验证了本文的可行性,并且总结了几种方法的优劣性及可能存在的问题,为进一步的研究提供了方向。
In the wireless mobile channel, to realize high speed and high quality service is the target and requirement of wireless communications. Orthogonal Frequency Division Multiplexing has attracted much attention for its high spectrum efficiency and strong immunity to frequency selective fading availably. Nevertheless, channel estimation is one of the key technologies for reliable transmission in OFDM system. In order to correctly demodulate information from sending terminal, it is therefore needed to estimate channel information accurately from receiving data. The accuracy of channel estimation will directly affect the performance of the whole system.
Firstly, this text analyzes some kinds of algorithms based on channel estimation using pilot symbols. Based on research of channel estimation applying m-sequence, using the mismatched sequence and sequence pairs channel estimation algorithm has been put forward in the circumstances of low complexity and higher accuracy. It compared with applying m-sequence and traditional algorithm by computer simulation.
Secondly, based on decision feedback channel estimation, this text directed towards the shortcoming of inaccuracy on traditional decision feedback. It put forward new algorithm that uses mismatched sequence or m-sequence to combine decision feedback respectively. Using the mismatch sequence and m-sequence could accurately estimate performance as the initial estimate for decision feedback. It is compared with applying mismatch sequence channel estimation and m-sequence channel estimation and decision feedback channel estimation. The result of simulation by MATLAB verified the feasibility of the paper. It summarized disadvantage and advantage about seveval methods, and provided the direction of the further research aspects.
引文
1周恩,张兴,吕召彪,等.下一代宽带无线通信OFDM与MIMO技术.北京:人民邮电出版社, 2008:1-3 130
2汪裕民. OFDM关键技术与应用.北京:机械工业出版社, 2007:1-4
3王文博,郑侃.宽带无线通信OFDM技术(第二版).北京:人民邮电出版社, 2007:6-10
4佟学俭,罗涛. OFDM移动通信技术原理与应用.北京:人民邮电出版社, 2003:34-36 53-55
5黄韬,袁超伟,杨睿哲. MIMO相关技术与应用.北京:机械工业出版社,2007:62-65
6张海滨.正交频分复用的基本原理与关键技术.北京:国防工业出版社, 2006:53-54
7 Jeong-Woo Jwa, Hwang-Soo Lee. Interleaved TC 8DPSK/OFDM with decision-directed channel estimation frequency-selective Rayleigh fading channels. Communications Letters, IEEE, 2002,6(10):413-415
8 Bu Xiang-Yuan, Zhang Jian-Kang, Yang Jing. Novel channel estimation method based on decision-directed in OFDM. Global Telecommunications Conference, Journal of Beijing Institute of Technology (English Edition), 2009, 1(18): 65-69
9 Muruganathan Siva D, Sesay Abu B. A low-complexity decision-directed channel estimation scheme for OFDM systems with space-frequency diversity in doubly selective fading channels. IEEE Trans. Veh. Technol, 2009,8: 4277-4291
10 Jianjun. Ran, Grunheid. R, Rohing. H. Decesion-directed channel estimation algorithm for OFDM systems with high velocities. Vehicular Technology Conference, 2003. VTC 2003-Spring. The 57th IEEE Semiannual, 2003, 3:2358-2361
11 Minjoong Rim, Jaemin Ahn, Yeon-soo Kirn. Decision-directe channel estimation for M-QAM-modulated OFDM systems. Vehicul Technology Conference, 2002. VTC. 2002, 4:1742-1746
12 Pei-yun Tsai, Tzi-Dar chiueh. Frequency-Domain Interpolation-Based ChannelEstimation in Pilot-Aided Systems. IEEE VTC 2004,1:420-424
13 Henrik Schober, Friedrich Jondral. Adaptive channel estimation OFDM based high speed Mobile Communication Systems. 2001 International Conference on Third Generation Wireless and Beyond, 2001:392-397
14 J.-J. van de Beek, O. Edfors, M. Sandell, et al. On channel estimation in OFDM systems. IEEE Vehicular Technology Conference, 1995, 2:815-819
15 O. Edfors, M. Sandell, J.-J. van de Beek, et al. OFDM channel estimation by singular value decomposition. IEEE Vehicular Technology Conference, 1996, 2:923-927
16 Hideo Kobayashi, Kazuo Mori. Proposal of OFDM channel estimation method using discrete cosine transform. IEEE International Symposium on Personal, Indoor and Mobile Radio Communications, 2004, 3:1797-1801
17 Sameer S.M, Kumar R. V. Raja. An efficient maximum likelihood carrier frequency offset estimation technique for OFDM systems. IEEE Symposium on Computers and Communications, 2008: 680-684
18 Rui Yun, Li Mingqi, Zhang Xiaodong. Noise variance optimization method for 2×1-dimensional wiener filtered channel estimation.Tien Tzu Hsueh Pao.2008, 8(36): 1577-1581
19 Fan Jiancun, Yin, Qinye, Wang Wenjie, et al. Pilot-aided channel estimation schemes for OFDM systems with cyclic delay diversity. IEEE Vehicular Technology Conference, 2009
20 Bossert. M, Donder. A, Zyablov. V. Improved channel estimation with decision feedback for OFDM systems. Eletronics Letters, 1998, 34(11):1064
21 Harada. Koji, Sakai. Hideak. Blind subspace-based channel estimation using the EM algorithm. ICASSP IEEE Int Conf Acoust Speech Signal Process Proc, 2009: 2797-2800
22 B. Muquest, M. de Courville, P. duhanme. A sub-space based blind and semi-blind channel identification method for OFDM systems. Second IEEE Workshop on SPAWC, 1999:170-173
23 G. B. Giannakis. Filterbanks for blind channel identification and equalization. IEEESignal Processing Letters. 1997, 4(6):184-187
24 R. Heath, G. B. Giannakis. Exploiting input cyclostationnarity for blind channel identification in OFDM systems. IEEE Trans Signal Processing. 1999, 47:848-856
25 M. Tsatsanis, G. B. Giannakis. Transmitter induced cyclostationarity for blind channel equalization. IEEE Trans Signal Processing. 1997, 45(7): 1785-1794
26 Shengli Zhou, Georgios B. Giannakis. Finite-alphabet based channel estimation for OFDM and related muticarrier systems. IEEE Trans On Communications. 2001, 49(8): 1402-1414
27 David Tse, Pramod Viswanath.无线通信基础.李锵,周进.北京:人民邮电出版社, 2007:10-13
28尹长川,罗涛,乐光新.多载波宽带无线通信技术.北京:北京邮电大学出版社, 2004:23-39
29 Ye Li, Gordon Stuber. Orthogonal Frequency Division Multiplexing for Wireless Communication. USA, School of Electrical & Computer Engineering, 2006: 19-21
30 Amine Laourine, Student Member. A new OFDM synchronization symbol for carrier frequency offset estimation. IEEE Signal Process Lett, 2007, 14(5):321-324
31 Mounir Ghogho, Ananthram Swami. Frame and Frequency Acquisition for OFDM. IEEE Signal Processing Letters, 2008,15: 605-608
32 J. Urban, R. Marsalek. PAPR Reduction by Combination of Interleaving with Repeated Clipping and Filtering in OFDM. 2007 17th International Conference Radioelektronika, 2007:423-425
33 Wen Jyh-Horng, Lee Shu-Hong. SLM-based PAPR reduction method using partial data circulation and side information insertion in OFDM systems. Institute of Commun Engineering, 2009: 87-100
34 Chen Chaoyu, Wang Chung-hsuan, Chao Chichao. Complementary sets and Reed-Muller coders for peak-to-average power ratio reduction in OFDM. Lecture Notes in Computer Science. 2006, 3857LNCS:317-327
35 M. Alard, R. Lassalle. Principles of modulation and channel coding for digital broadcasting for mobile receivers. EBU Technical Review, 1987:168-190
36 Y. Zhao, A. Huang. A Novel Channel Estimation Method for OFDM Mobile Communication Systems Based on Pilot Signals and Transform-Domain Processing. IEEE Vehicular Technology Conference. 1997, 3:2089-2094
37 Yen-Hui Yeh, Sau-Gee Chen. DCT-Based Channel Estimation for OFDM Systems. IEEE Int Conf Commun, 2004, 4: 2442-2446
38 Chen. Pei, Kobayashi. Hisash. Maximum likelihood channel estimation and signal detection for OFDM systems. IEEE Int Conf Commun, 2002, 3:1640-1645
39盛骤.概率论与数理统计.北京:高等教育出版社, 2001, 3:22-24
40 Fritsch, Carlson R. Monotone piecewise cubic interpolation. SIAM J. Numerical Analysis, 1980, 17(2):238-246
41 Jean-Jacques Fuchs, Delyon B. Min-max interpolators and Lagrange interpolation formula. IEEE ISCAS, 2002:429-432
42 3rd Generation Partnership Project -3GPP TR 25.943, V 8.0.0 , Technical Specification Group Radio Access Network , Department Aspects. 2008:7-10
43樊昌信,张甫翊,徐炳祥.通信原理.第5版.北京:国防工业出版社,2004:326-336
44田日才.扩频通信.北京:清华大学出版社, 2007:49-53
45许国平,张欣,杨大成.一种低复杂度的MIMO-OFDM信道估计新方法.电子与信息学报, 2008,30(4):797-800
46 Singh M P. Peering at Peer-to-peer Computing. IEEE Internet Computing, 2001, 5(1): 4-5
47 Hans Dieter Lüke. Mismatched Filtering of Periodic Quadriphase and 8-Phase Sequences. IEEE Trans Commun, 2003, 51(7): 1061-1063
48 Hermann Rohling, Wilfried Plagge. Mismatched-filter design for periodical binary phased signals. IEEE Transactions on Aerospace and Electronic Systems. 1989:
890-897
49 A. Molina, P. C. Fannin. Application of mismatched filter theory to bandpass impulse response measurements. Electron Letters, 1993, 29(2): 162-163
50赵晓群,贾世楼,王仲文.序列偶及其应用.遥测遥控, 1998:31-35
51 Jianjun. Ran, Grunheid. R, Rohing. H. Decesion-directed channel estimation algorithmfor OFDM systems with high velocities. Vehicular Technology Conference, 2003. VTC 2003-Spring. The 57th IEEE Semiannual, 2003, 3:2358-2361
52 V.Mignone V.Morello A.ViSintin M CD3-OFDM:a new channel estimation method to improve the spectrum efficiency in digital terrestrial television systems, 1995:122-128
53 Ahmad R. S. Bahai, B.R. Saltzberg. Multi-Carrier Digital Communication Theory and Application of OFDM. Kluwer Academic IPlenum Publisher. NewYork,1999:103-109
2汪裕民. OFDM关键技术与应用.北京:机械工业出版社, 2007:1-4
3王文博,郑侃.宽带无线通信OFDM技术(第二版).北京:人民邮电出版社, 2007:6-10
4佟学俭,罗涛. OFDM移动通信技术原理与应用.北京:人民邮电出版社, 2003:34-36 53-55
5黄韬,袁超伟,杨睿哲. MIMO相关技术与应用.北京:机械工业出版社,2007:62-65
6张海滨.正交频分复用的基本原理与关键技术.北京:国防工业出版社, 2006:53-54
7 Jeong-Woo Jwa, Hwang-Soo Lee. Interleaved TC 8DPSK/OFDM with decision-directed channel estimation frequency-selective Rayleigh fading channels. Communications Letters, IEEE, 2002,6(10):413-415
8 Bu Xiang-Yuan, Zhang Jian-Kang, Yang Jing. Novel channel estimation method based on decision-directed in OFDM. Global Telecommunications Conference, Journal of Beijing Institute of Technology (English Edition), 2009, 1(18): 65-69
9 Muruganathan Siva D, Sesay Abu B. A low-complexity decision-directed channel estimation scheme for OFDM systems with space-frequency diversity in doubly selective fading channels. IEEE Trans. Veh. Technol, 2009,8: 4277-4291
10 Jianjun. Ran, Grunheid. R, Rohing. H. Decesion-directed channel estimation algorithm for OFDM systems with high velocities. Vehicular Technology Conference, 2003. VTC 2003-Spring. The 57th IEEE Semiannual, 2003, 3:2358-2361
11 Minjoong Rim, Jaemin Ahn, Yeon-soo Kirn. Decision-directe channel estimation for M-QAM-modulated OFDM systems. Vehicul Technology Conference, 2002. VTC. 2002, 4:1742-1746
12 Pei-yun Tsai, Tzi-Dar chiueh. Frequency-Domain Interpolation-Based ChannelEstimation in Pilot-Aided Systems. IEEE VTC 2004,1:420-424
13 Henrik Schober, Friedrich Jondral. Adaptive channel estimation OFDM based high speed Mobile Communication Systems. 2001 International Conference on Third Generation Wireless and Beyond, 2001:392-397
14 J.-J. van de Beek, O. Edfors, M. Sandell, et al. On channel estimation in OFDM systems. IEEE Vehicular Technology Conference, 1995, 2:815-819
15 O. Edfors, M. Sandell, J.-J. van de Beek, et al. OFDM channel estimation by singular value decomposition. IEEE Vehicular Technology Conference, 1996, 2:923-927
16 Hideo Kobayashi, Kazuo Mori. Proposal of OFDM channel estimation method using discrete cosine transform. IEEE International Symposium on Personal, Indoor and Mobile Radio Communications, 2004, 3:1797-1801
17 Sameer S.M, Kumar R. V. Raja. An efficient maximum likelihood carrier frequency offset estimation technique for OFDM systems. IEEE Symposium on Computers and Communications, 2008: 680-684
18 Rui Yun, Li Mingqi, Zhang Xiaodong. Noise variance optimization method for 2×1-dimensional wiener filtered channel estimation.Tien Tzu Hsueh Pao.2008, 8(36): 1577-1581
19 Fan Jiancun, Yin, Qinye, Wang Wenjie, et al. Pilot-aided channel estimation schemes for OFDM systems with cyclic delay diversity. IEEE Vehicular Technology Conference, 2009
20 Bossert. M, Donder. A, Zyablov. V. Improved channel estimation with decision feedback for OFDM systems. Eletronics Letters, 1998, 34(11):1064
21 Harada. Koji, Sakai. Hideak. Blind subspace-based channel estimation using the EM algorithm. ICASSP IEEE Int Conf Acoust Speech Signal Process Proc, 2009: 2797-2800
22 B. Muquest, M. de Courville, P. duhanme. A sub-space based blind and semi-blind channel identification method for OFDM systems. Second IEEE Workshop on SPAWC, 1999:170-173
23 G. B. Giannakis. Filterbanks for blind channel identification and equalization. IEEESignal Processing Letters. 1997, 4(6):184-187
24 R. Heath, G. B. Giannakis. Exploiting input cyclostationnarity for blind channel identification in OFDM systems. IEEE Trans Signal Processing. 1999, 47:848-856
25 M. Tsatsanis, G. B. Giannakis. Transmitter induced cyclostationarity for blind channel equalization. IEEE Trans Signal Processing. 1997, 45(7): 1785-1794
26 Shengli Zhou, Georgios B. Giannakis. Finite-alphabet based channel estimation for OFDM and related muticarrier systems. IEEE Trans On Communications. 2001, 49(8): 1402-1414
27 David Tse, Pramod Viswanath.无线通信基础.李锵,周进.北京:人民邮电出版社, 2007:10-13
28尹长川,罗涛,乐光新.多载波宽带无线通信技术.北京:北京邮电大学出版社, 2004:23-39
29 Ye Li, Gordon Stuber. Orthogonal Frequency Division Multiplexing for Wireless Communication. USA, School of Electrical & Computer Engineering, 2006: 19-21
30 Amine Laourine, Student Member. A new OFDM synchronization symbol for carrier frequency offset estimation. IEEE Signal Process Lett, 2007, 14(5):321-324
31 Mounir Ghogho, Ananthram Swami. Frame and Frequency Acquisition for OFDM. IEEE Signal Processing Letters, 2008,15: 605-608
32 J. Urban, R. Marsalek. PAPR Reduction by Combination of Interleaving with Repeated Clipping and Filtering in OFDM. 2007 17th International Conference Radioelektronika, 2007:423-425
33 Wen Jyh-Horng, Lee Shu-Hong. SLM-based PAPR reduction method using partial data circulation and side information insertion in OFDM systems. Institute of Commun Engineering, 2009: 87-100
34 Chen Chaoyu, Wang Chung-hsuan, Chao Chichao. Complementary sets and Reed-Muller coders for peak-to-average power ratio reduction in OFDM. Lecture Notes in Computer Science. 2006, 3857LNCS:317-327
35 M. Alard, R. Lassalle. Principles of modulation and channel coding for digital broadcasting for mobile receivers. EBU Technical Review, 1987:168-190
36 Y. Zhao, A. Huang. A Novel Channel Estimation Method for OFDM Mobile Communication Systems Based on Pilot Signals and Transform-Domain Processing. IEEE Vehicular Technology Conference. 1997, 3:2089-2094
37 Yen-Hui Yeh, Sau-Gee Chen. DCT-Based Channel Estimation for OFDM Systems. IEEE Int Conf Commun, 2004, 4: 2442-2446
38 Chen. Pei, Kobayashi. Hisash. Maximum likelihood channel estimation and signal detection for OFDM systems. IEEE Int Conf Commun, 2002, 3:1640-1645
39盛骤.概率论与数理统计.北京:高等教育出版社, 2001, 3:22-24
40 Fritsch, Carlson R. Monotone piecewise cubic interpolation. SIAM J. Numerical Analysis, 1980, 17(2):238-246
41 Jean-Jacques Fuchs, Delyon B. Min-max interpolators and Lagrange interpolation formula. IEEE ISCAS, 2002:429-432
42 3rd Generation Partnership Project -3GPP TR 25.943, V 8.0.0 , Technical Specification Group Radio Access Network , Department Aspects. 2008:7-10
43樊昌信,张甫翊,徐炳祥.通信原理.第5版.北京:国防工业出版社,2004:326-336
44田日才.扩频通信.北京:清华大学出版社, 2007:49-53
45许国平,张欣,杨大成.一种低复杂度的MIMO-OFDM信道估计新方法.电子与信息学报, 2008,30(4):797-800
46 Singh M P. Peering at Peer-to-peer Computing. IEEE Internet Computing, 2001, 5(1): 4-5
47 Hans Dieter Lüke. Mismatched Filtering of Periodic Quadriphase and 8-Phase Sequences. IEEE Trans Commun, 2003, 51(7): 1061-1063
48 Hermann Rohling, Wilfried Plagge. Mismatched-filter design for periodical binary phased signals. IEEE Transactions on Aerospace and Electronic Systems. 1989:
890-897
49 A. Molina, P. C. Fannin. Application of mismatched filter theory to bandpass impulse response measurements. Electron Letters, 1993, 29(2): 162-163
50赵晓群,贾世楼,王仲文.序列偶及其应用.遥测遥控, 1998:31-35
51 Jianjun. Ran, Grunheid. R, Rohing. H. Decesion-directed channel estimation algorithmfor OFDM systems with high velocities. Vehicular Technology Conference, 2003. VTC 2003-Spring. The 57th IEEE Semiannual, 2003, 3:2358-2361
52 V.Mignone V.Morello A.ViSintin M CD3-OFDM:a new channel estimation method to improve the spectrum efficiency in digital terrestrial television systems, 1995:122-128
53 Ahmad R. S. Bahai, B.R. Saltzberg. Multi-Carrier Digital Communication Theory and Application of OFDM. Kluwer Academic IPlenum Publisher. NewYork,1999:103-109