未来无线通信系统导频设计技术研究
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摘要
下一代移动通信系统是一个高频谱利用率、高传输速率,并可提供多种服务的无线网络。为了满足这些要求,需要应用新的无线空中接口技术,以正交频分复用技术为核心的超三代移动通信系统应运而生。本文主要就超三代移动通信体系中多小区环境下的信道估计、导频设计进行分析研究。
本文首先介绍了无线信道特性及其模型、蜂窝小区、多小区同频干扰模型,以便更深刻地理解仿真设计中所考虑的环境。紧接着,描述了正交频分复用系统的原理和结构,最优导频设计,系统地总结了几种常用信道估计和插值算法,将最小二乘法,最小均方误差法,傅里叶变换法等各种信道估计算法和级联的一维插值算法进行了性能评估,并讨论了实际系统中循环前缀截取对于信道估计性能的影响。
在上述工作的基础上,论文重点讨论了在多小区环境下,如何通过导频的优化设计来抑制信道估计过程中来自于其他小区的同频干扰。提出了基于恒包络零自相关(CAZAC, Constant Amplitude and Zero Auto Correlation)序列作为导频序列的改进方案,考虑序列长度为非素数的情况,提出了最优导频序列和次优导频序列混合使用的方法,并与3G长期演进(LTE, Long Term Evolution)系统中的上行导频设计方案进行了比较。通过理论推导和仿真发现,此方法可以更好地抑制小区内多用户干扰和小区间的同频干扰。
进一步地,本文研究了在获得信道估计的基础上,如何在发送端、接收端充分利用该信道信息来优化系统设计的问题。本文详细介绍了一种在多小区环境下基于多天线正交频分复用系统的自适应算法,利用闭环链路反馈的部分信道信息来抑制小区间干扰和小区内的高斯白噪声,提升多小区环境下的信干比,从而更有效地使用所获取的信道信息。
The next generation mobile communication systems will have higher spectrum efficiency, higher transmission rate, and provide multimedia services to the users. In order to achieve above targets, new wireless air interface technologies must be applied. Orthogonal Frequency Division Multiplexing is one of the candidate technologies in B3G systems. This thesis focuses on the channel estimation and pilot design technology in OFDM-based B3G systems under multi-cell environment.
For deeper understanding of the simulation-design in our considered environment, this thesis first describes the wireless channel characteristics and models, cellular cell and multi-cell model with co-frequency interferences. And then, this thesis introduces the principle and structure of OFDM systems and the issue of optimal pilot design, summarizes several common channel estimation techniques and interpolation algorithms in OFDM system, and evaluates the performance of LS, MMSE, DFT channel estimation algorithms, and discusses the influence of cyclic prefix interception on channel estimation performance in the actual system.
Based on above works, this thesis pays attention to the issue of pilot design technologies to suppress the co-frequency interferences from other cells in the process of channel estimation in multi-cell environments. This thesis presents a pilot design proposal based on constant amplitude and zero autocorrelation (CAZAC) sequence. The proposal breaks the sequence length limit of prime number in long term evolution (LTE) system. Instead, the length is expanded to a broader scope. This proposal also proposes a method by mixed use the optimal pilot sequences and sub-optimal pilot sequences, so that improves the original design of pilot in the uplink of LTE system. It is found that this method can significantly inhibit the intra-cell multi-user interference and the inter-cell co-frequency interference.
Furthermore, this thesis investigates how to make use of the channel information at the transmitter and the receiver after we get knowledge of channel through channel estimation. This thesis describes an adaptive algorithm in multi-cell environment, which uses partial channel information feedback from closed-loop link to suppress inter-cell interference and intra-cell Gaussian noise. This adaptive algorithm is shown to enhance the signal-to-interference ratio in multi-cell environment and make use of the channel state information more efficiently.
本文首先介绍了无线信道特性及其模型、蜂窝小区、多小区同频干扰模型,以便更深刻地理解仿真设计中所考虑的环境。紧接着,描述了正交频分复用系统的原理和结构,最优导频设计,系统地总结了几种常用信道估计和插值算法,将最小二乘法,最小均方误差法,傅里叶变换法等各种信道估计算法和级联的一维插值算法进行了性能评估,并讨论了实际系统中循环前缀截取对于信道估计性能的影响。
在上述工作的基础上,论文重点讨论了在多小区环境下,如何通过导频的优化设计来抑制信道估计过程中来自于其他小区的同频干扰。提出了基于恒包络零自相关(CAZAC, Constant Amplitude and Zero Auto Correlation)序列作为导频序列的改进方案,考虑序列长度为非素数的情况,提出了最优导频序列和次优导频序列混合使用的方法,并与3G长期演进(LTE, Long Term Evolution)系统中的上行导频设计方案进行了比较。通过理论推导和仿真发现,此方法可以更好地抑制小区内多用户干扰和小区间的同频干扰。
进一步地,本文研究了在获得信道估计的基础上,如何在发送端、接收端充分利用该信道信息来优化系统设计的问题。本文详细介绍了一种在多小区环境下基于多天线正交频分复用系统的自适应算法,利用闭环链路反馈的部分信道信息来抑制小区间干扰和小区内的高斯白噪声,提升多小区环境下的信干比,从而更有效地使用所获取的信道信息。
The next generation mobile communication systems will have higher spectrum efficiency, higher transmission rate, and provide multimedia services to the users. In order to achieve above targets, new wireless air interface technologies must be applied. Orthogonal Frequency Division Multiplexing is one of the candidate technologies in B3G systems. This thesis focuses on the channel estimation and pilot design technology in OFDM-based B3G systems under multi-cell environment.
For deeper understanding of the simulation-design in our considered environment, this thesis first describes the wireless channel characteristics and models, cellular cell and multi-cell model with co-frequency interferences. And then, this thesis introduces the principle and structure of OFDM systems and the issue of optimal pilot design, summarizes several common channel estimation techniques and interpolation algorithms in OFDM system, and evaluates the performance of LS, MMSE, DFT channel estimation algorithms, and discusses the influence of cyclic prefix interception on channel estimation performance in the actual system.
Based on above works, this thesis pays attention to the issue of pilot design technologies to suppress the co-frequency interferences from other cells in the process of channel estimation in multi-cell environments. This thesis presents a pilot design proposal based on constant amplitude and zero autocorrelation (CAZAC) sequence. The proposal breaks the sequence length limit of prime number in long term evolution (LTE) system. Instead, the length is expanded to a broader scope. This proposal also proposes a method by mixed use the optimal pilot sequences and sub-optimal pilot sequences, so that improves the original design of pilot in the uplink of LTE system. It is found that this method can significantly inhibit the intra-cell multi-user interference and the inter-cell co-frequency interference.
Furthermore, this thesis investigates how to make use of the channel information at the transmitter and the receiver after we get knowledge of channel through channel estimation. This thesis describes an adaptive algorithm in multi-cell environment, which uses partial channel information feedback from closed-loop link to suppress inter-cell interference and intra-cell Gaussian noise. This adaptive algorithm is shown to enhance the signal-to-interference ratio in multi-cell environment and make use of the channel state information more efficiently.
引文
[1]P.W. Baier, M. Meurer, "Air interface enhancements for 3G and beyond-3G mobile radio communications", Proc.9th International Conference on Telecommunications (ICT'02),2002, pp.284-291.
[2]R. Berezdivin, R. Breinig, R. Topp, "Next-generation wireless communications concepts and technologies", IEEE Communications Magazine, vol.40,2002, pp.108-116.
[3]Y. Kim, B.J. Jeong, J. Chung, C. Hwang, J.S. Ryu, K. Kim, Y.K. Kim, "Beyond 3G:vision, requirements, and enabling technologies", IEEE Communications Magazine, vol.41,2003, pp.120-124.
[4]3GPP, R1-050611, "Characteristics of Evolved UTRA TDD system", RITT.
[5]3GPP, R1-050790, "PAPR reduction for TDD uplink OFDMA", RITT, CATT, Huawei.
[6]3GPP, R1-051178, "Frame structure design and analyze of OFDM TDD for LTE", CATT, RITT, TD-Tech, ZTE, Huawei.
[7]W.W.Lu.Broadband Wireless Communications:3G and Beyond. New York:John Wiley and Sons,2002.
[8]Franziskus Bauer, Arnaud Gueguen, Sylvie Matrargue, et al. Sunthesis Report on worldwide research on 4G systems, European Commission IST-2001-32620 MATRICE Deliverable D1.4.
[9]S.Hara, R.Prasad. Multicarrier techniques for 4G mobile communications. Boston, Mass:Artech house,2003.
[10]I.E.Telatar, "Capacity of multi-antenna Gaussian channel", European Transaction on Telecommunications, Vol.20, No.6, pp585-595, Nov./Dec.1999.
[11]G. J. Foschini, M. J. Gans, "On limits of wireless communications in a fading environment when using multiple antennas", Wireless Pers. Communications, Vol.6, 1998, pp311-335.
[12]Da-Shan Shiu, Foschini, G.J."Fading correlation and its effect on the capacity of multielement antenna systems", IEEE Transactions on Communications, Vol48, No.3, pp 502-513, Mar.2000.
[13]Yifei Zhao, Ming Zhao, "Capacity of Time-Varying Rayleigh Fading MIMO Channels", IEEE PIMRC 2005, Vol 1,11-14,pp:547-551, Sept.2005.
[14]Molisch, A.F, Steinbauer, M, "Measurement of the capacity of MIMO systems in frequency-selective channels", VTC 2001, Spring. IEEE VTS 53rd, vol.1, pp204-208,6-9 May 2001.
[15]Yingwei Yao, Giannakis, G.B, "Rate-maximizing power allocation in OFDM based on partial channel knowledge", IEEE Transactions on Wireless Communications, Vol.4, No3, pp:1073-1083, May 2005.
[16]Raleigh, G.G., Cioffi, J.M., "Spatio-temporal coding for wireless communication", IEEE Transactions on Communications, Vol.46, No.3, pp357-366, March 1998.
[17]Kai-Kit Wong, Cheng, R.S.K., "Adaptive antennas at the mobile and base stations in an OFDM/TDMA system", IEEE Transactions on Communications, Vol.49, No.l, pp 195-206, Jan.2001.
[18]Pengfei Xia, Shengli Zhou, "adaptive mimo-ofdm based on partial channel state information", IEEE Transactions on Signal Processing, Vol.52, No.1, pp 202-213, Jan 2004.
[1]尹长川,罗涛,乐光新，多载波宽带无线通信技术,北京邮电大学出版社,2004,pp.13-16。
[2]John G. Proakis. Digital Communications(Fourth Edition).北京：电子工业出版社.2003.
[3]杨大成等,移动传播环境,机械工业出版社,2003.8.
[4]Jari Salo, Giovanni Del Gaodo, Jussi Salmi, Pekka Kyosti, Marko Milojevic, Daniela Laselva, Christian Schneider, "MATLAB implementation of the 3GPP Spatial Channel Model (3GPP TR 25.996)".
[5]Daniel S. Baum, Jari Salo, Marko Milojevic, Pekka Kyosti, Jan Hansen, "MATLAB implementation of the 3GPP Spatial Channel Model Extended (SCME)".
[6]韦惠民,李白萍,蜂窝移动通信技术,西安电子科技大学出版社,2002.8.
[7]华为技术有限公司,GSM无线网络规划与优化,人民邮电出版社,2004.6.
[1]Doelz. G. A, Heald. E. T, Martin. D. L, "Binary data transmission techniques for linear systems," Proc. I. R. E., May.1957, Vol.45, pp.656-661.
[2]Chang. R. W, "Synthesis of band-limited orthogonal signals for multichannel data transmission," Bell Sys. Tech. J., Dec.1966, Vol.45, pp.1775-1796.
[3]Weinstein. S. B, Ebert. P. M, "Data transmission by frequency division multiplexing using the discrete Fourier transform," IEEE Trans. Commun., Oct.1971, Vol.19(5), pp.628-634.
[4]Peled. A, Ruiz. A, "Frequency domain data transmission using reduced computational complexity algorithms," IEEE Conf. Acoust Speech Signal Processing, Denver,1980, pp.964-967.
[5]Cimini. L. J, "Analysis and simulation of a digital mobile channel using Orthogonal Frequency Division Multiplexing," IEEE Trans. Commun., July.1985, Vol.33(7), pp.665-675.
[6]尹长川,罗涛,乐光新,多载波宽带无线通信技术,北京邮电大学出版社,2004,pp.28-19。
[7]3GPP LTE R1-050881. Time vs frequency domain realization of SC-FDMA transmissions,2005.
[8]3GPP LTE R1-050269. Uplink multiple access for evolved UTRA radio interface, 2005.
[9]3GPP LTE TR 25.814 v 0.4.2.
[10]I.E.Telatar, "Capacity of multi-antenna Gaussian channel", European Transaction on Telecommunications, Vol.20, No.6, pp585-595, Nov./Dec.1999.
[11]G. J. Foschini, M. J. Gans, "On limits of wireless communications in a fading environment when using multiple antennas", Wireless Pers. Communications, Vol.6, 1998, pp311-335.
[12]Hu. D, He. L. H, Yang. L. X, "Estimation of rapidly time-varying channels for OFDM systems," IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP'06), Toulouse, May.2006, Vol.4, pp.357-360.
[13]Mignone. V, Morello. A, "CD3-OFDM:A novel demodulation scheme for fixed and mobile receivers," IEEE Trans. Commun., Sept.1996, Vol.44, pp.1144-1151.
[14]Rohit Negi. John Cioffi. Pilot Tone Selection for Channel Estimation In A Mobile OFDM System. IEEE Transactions on vehicular technology. Vol 44.1998, August:1122-1128.
[15]Jan-Jaap. van de Beek. Ove Edfors. On Channel Estimation in OFDM Systems. IEEE Transactions on vehicular technology. Vol 2.1995:1303-1307.
[16]Fredrik Tufvesson. Torleiv Maseng. Pilot assisted channel estimation for OFDM in mobile cellular system. IEEE Transactions on vehicular technology. Vol 3.1997:1639～1643.
[17]李详明.多载波调制理论及其在无线CDMA中应用的一些关键技术研究.[学位论文].北京：北京邮电大学.2000.
[18]李道本.信号的统计检测与估计理论.北京：北京邮电大学出版社.1996.
[19]S. Weinstein, P. Ebert, "Data transmission by frequency-division multiplexing using the discrete Fourier transform," IEEE Trans. on Comm.,19(5), Oct.1971, pp. 628-634.
[20]Peled, A. Ruiz, "Frequency domain data transmission using reduced computational complexity algorithms," Proc. IEEE Int. Cof. Acoust Speech Signal Processing, Denver,1980, pp.964-967.
[1]H. Minn and N. Al-Dhahir. "Optimal training signals for mimo ofdm channel estimation" IEEE Globecom 2004, pp.219-224,2004.
[2]D. C. Chu, "Polyphase Codes With Good Periodic Correlation Properties", IEEE Transactions on Information Theory, Vol.18, July 1973, pp.531-532.
[3]R1-070190, Panasonic, NTT DoCoMo, "Uplink reference signal structure and allocation for E-UTRA".
[4]R1-060878, Motorola, "EUTRA SC-FDMA Uplink Pilot/Reference Signal Design & TP".
[1]Yifei Zhao, Ming Zhao, "Capacity of Time-Varying Rayleigh Fading MIMO Channels", IEEE PIMRC 2005, Vol 1,11-14,pp:547-551, Sept.2005.
[2]Molisch, A.F, Steinbauer, M, "Measurement of the capacity of MIMO systems in frequency-selective channels", VTC 2001, Spring. IEEE VTS 53rd, vol.1, pp204-208,6-9 May 2001.
[3]Da-Shan Shiu, Foschini, G.J."Fading correlation and its effect on the capacity of multielement antenna systems", IEEE Transactions on Communications, Vol48, No.3, pp 502-513, Mar.2000.
[4]Yingwei Yao, Giannakis, G.B, "Rate-maximizing power allocation in OFDM based on partial channel knowledge", IEEE Transactions on Wireless Communications, Vol.4, No3, pp:1073-1083, May 2005.
[5]Pengfei Xia, Shengli Zhou, "adaptive mimo-ofdm based on partial channel state information", IEEE Transactions on Signal Processing, Vol.52, No.1, pp 202-213, Jan 2004.
[6]Jihoon Choj, Heath R. W., Jr., "Interpolation based unitary precoding for spatial multiplexing MIMO-OFDM with limited feedback," Global Telecommunications Conference,2004, vol.1, pp214-218, Nov.2004
[7]Imran Mushtaq, Andrew Logothetis, Bo Goransson, Mats Viberg, "3G Transmit diversity and inter-cell Interference Suppression using Multiple Antenna Terminals," VTC,2002, vol.4, pp2512-2516, Sept.2002
[8]R. S. Blum, "MIMO Capacity with Interference," IEEE J. Select. Areas Communication, vol.21, NO.5, pp793-801, June 2003
[9]T. M. Cover and J. A. Thomas, Elements of Information Theory, New York, USA,: John Wiley,1991
[2]R. Berezdivin, R. Breinig, R. Topp, "Next-generation wireless communications concepts and technologies", IEEE Communications Magazine, vol.40,2002, pp.108-116.
[3]Y. Kim, B.J. Jeong, J. Chung, C. Hwang, J.S. Ryu, K. Kim, Y.K. Kim, "Beyond 3G:vision, requirements, and enabling technologies", IEEE Communications Magazine, vol.41,2003, pp.120-124.
[4]3GPP, R1-050611, "Characteristics of Evolved UTRA TDD system", RITT.
[5]3GPP, R1-050790, "PAPR reduction for TDD uplink OFDMA", RITT, CATT, Huawei.
[6]3GPP, R1-051178, "Frame structure design and analyze of OFDM TDD for LTE", CATT, RITT, TD-Tech, ZTE, Huawei.
[7]W.W.Lu.Broadband Wireless Communications:3G and Beyond. New York:John Wiley and Sons,2002.
[8]Franziskus Bauer, Arnaud Gueguen, Sylvie Matrargue, et al. Sunthesis Report on worldwide research on 4G systems, European Commission IST-2001-32620 MATRICE Deliverable D1.4.
[9]S.Hara, R.Prasad. Multicarrier techniques for 4G mobile communications. Boston, Mass:Artech house,2003.
[10]I.E.Telatar, "Capacity of multi-antenna Gaussian channel", European Transaction on Telecommunications, Vol.20, No.6, pp585-595, Nov./Dec.1999.
[11]G. J. Foschini, M. J. Gans, "On limits of wireless communications in a fading environment when using multiple antennas", Wireless Pers. Communications, Vol.6, 1998, pp311-335.
[12]Da-Shan Shiu, Foschini, G.J."Fading correlation and its effect on the capacity of multielement antenna systems", IEEE Transactions on Communications, Vol48, No.3, pp 502-513, Mar.2000.
[13]Yifei Zhao, Ming Zhao, "Capacity of Time-Varying Rayleigh Fading MIMO Channels", IEEE PIMRC 2005, Vol 1,11-14,pp:547-551, Sept.2005.
[14]Molisch, A.F, Steinbauer, M, "Measurement of the capacity of MIMO systems in frequency-selective channels", VTC 2001, Spring. IEEE VTS 53rd, vol.1, pp204-208,6-9 May 2001.
[15]Yingwei Yao, Giannakis, G.B, "Rate-maximizing power allocation in OFDM based on partial channel knowledge", IEEE Transactions on Wireless Communications, Vol.4, No3, pp:1073-1083, May 2005.
[16]Raleigh, G.G., Cioffi, J.M., "Spatio-temporal coding for wireless communication", IEEE Transactions on Communications, Vol.46, No.3, pp357-366, March 1998.
[17]Kai-Kit Wong, Cheng, R.S.K., "Adaptive antennas at the mobile and base stations in an OFDM/TDMA system", IEEE Transactions on Communications, Vol.49, No.l, pp 195-206, Jan.2001.
[18]Pengfei Xia, Shengli Zhou, "adaptive mimo-ofdm based on partial channel state information", IEEE Transactions on Signal Processing, Vol.52, No.1, pp 202-213, Jan 2004.
[1]尹长川,罗涛,乐光新，多载波宽带无线通信技术,北京邮电大学出版社,2004,pp.13-16。
[2]John G. Proakis. Digital Communications(Fourth Edition).北京：电子工业出版社.2003.
[3]杨大成等,移动传播环境,机械工业出版社,2003.8.
[4]Jari Salo, Giovanni Del Gaodo, Jussi Salmi, Pekka Kyosti, Marko Milojevic, Daniela Laselva, Christian Schneider, "MATLAB implementation of the 3GPP Spatial Channel Model (3GPP TR 25.996)".
[5]Daniel S. Baum, Jari Salo, Marko Milojevic, Pekka Kyosti, Jan Hansen, "MATLAB implementation of the 3GPP Spatial Channel Model Extended (SCME)".
[6]韦惠民,李白萍,蜂窝移动通信技术,西安电子科技大学出版社,2002.8.
[7]华为技术有限公司,GSM无线网络规划与优化,人民邮电出版社,2004.6.
[1]Doelz. G. A, Heald. E. T, Martin. D. L, "Binary data transmission techniques for linear systems," Proc. I. R. E., May.1957, Vol.45, pp.656-661.
[2]Chang. R. W, "Synthesis of band-limited orthogonal signals for multichannel data transmission," Bell Sys. Tech. J., Dec.1966, Vol.45, pp.1775-1796.
[3]Weinstein. S. B, Ebert. P. M, "Data transmission by frequency division multiplexing using the discrete Fourier transform," IEEE Trans. Commun., Oct.1971, Vol.19(5), pp.628-634.
[4]Peled. A, Ruiz. A, "Frequency domain data transmission using reduced computational complexity algorithms," IEEE Conf. Acoust Speech Signal Processing, Denver,1980, pp.964-967.
[5]Cimini. L. J, "Analysis and simulation of a digital mobile channel using Orthogonal Frequency Division Multiplexing," IEEE Trans. Commun., July.1985, Vol.33(7), pp.665-675.
[6]尹长川,罗涛,乐光新,多载波宽带无线通信技术,北京邮电大学出版社,2004,pp.28-19。
[7]3GPP LTE R1-050881. Time vs frequency domain realization of SC-FDMA transmissions,2005.
[8]3GPP LTE R1-050269. Uplink multiple access for evolved UTRA radio interface, 2005.
[9]3GPP LTE TR 25.814 v 0.4.2.
[10]I.E.Telatar, "Capacity of multi-antenna Gaussian channel", European Transaction on Telecommunications, Vol.20, No.6, pp585-595, Nov./Dec.1999.
[11]G. J. Foschini, M. J. Gans, "On limits of wireless communications in a fading environment when using multiple antennas", Wireless Pers. Communications, Vol.6, 1998, pp311-335.
[12]Hu. D, He. L. H, Yang. L. X, "Estimation of rapidly time-varying channels for OFDM systems," IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP'06), Toulouse, May.2006, Vol.4, pp.357-360.
[13]Mignone. V, Morello. A, "CD3-OFDM:A novel demodulation scheme for fixed and mobile receivers," IEEE Trans. Commun., Sept.1996, Vol.44, pp.1144-1151.
[14]Rohit Negi. John Cioffi. Pilot Tone Selection for Channel Estimation In A Mobile OFDM System. IEEE Transactions on vehicular technology. Vol 44.1998, August:1122-1128.
[15]Jan-Jaap. van de Beek. Ove Edfors. On Channel Estimation in OFDM Systems. IEEE Transactions on vehicular technology. Vol 2.1995:1303-1307.
[16]Fredrik Tufvesson. Torleiv Maseng. Pilot assisted channel estimation for OFDM in mobile cellular system. IEEE Transactions on vehicular technology. Vol 3.1997:1639～1643.
[17]李详明.多载波调制理论及其在无线CDMA中应用的一些关键技术研究.[学位论文].北京：北京邮电大学.2000.
[18]李道本.信号的统计检测与估计理论.北京：北京邮电大学出版社.1996.
[19]S. Weinstein, P. Ebert, "Data transmission by frequency-division multiplexing using the discrete Fourier transform," IEEE Trans. on Comm.,19(5), Oct.1971, pp. 628-634.
[20]Peled, A. Ruiz, "Frequency domain data transmission using reduced computational complexity algorithms," Proc. IEEE Int. Cof. Acoust Speech Signal Processing, Denver,1980, pp.964-967.
[1]H. Minn and N. Al-Dhahir. "Optimal training signals for mimo ofdm channel estimation" IEEE Globecom 2004, pp.219-224,2004.
[2]D. C. Chu, "Polyphase Codes With Good Periodic Correlation Properties", IEEE Transactions on Information Theory, Vol.18, July 1973, pp.531-532.
[3]R1-070190, Panasonic, NTT DoCoMo, "Uplink reference signal structure and allocation for E-UTRA".
[4]R1-060878, Motorola, "EUTRA SC-FDMA Uplink Pilot/Reference Signal Design & TP".
[1]Yifei Zhao, Ming Zhao, "Capacity of Time-Varying Rayleigh Fading MIMO Channels", IEEE PIMRC 2005, Vol 1,11-14,pp:547-551, Sept.2005.
[2]Molisch, A.F, Steinbauer, M, "Measurement of the capacity of MIMO systems in frequency-selective channels", VTC 2001, Spring. IEEE VTS 53rd, vol.1, pp204-208,6-9 May 2001.
[3]Da-Shan Shiu, Foschini, G.J."Fading correlation and its effect on the capacity of multielement antenna systems", IEEE Transactions on Communications, Vol48, No.3, pp 502-513, Mar.2000.
[4]Yingwei Yao, Giannakis, G.B, "Rate-maximizing power allocation in OFDM based on partial channel knowledge", IEEE Transactions on Wireless Communications, Vol.4, No3, pp:1073-1083, May 2005.
[5]Pengfei Xia, Shengli Zhou, "adaptive mimo-ofdm based on partial channel state information", IEEE Transactions on Signal Processing, Vol.52, No.1, pp 202-213, Jan 2004.
[6]Jihoon Choj, Heath R. W., Jr., "Interpolation based unitary precoding for spatial multiplexing MIMO-OFDM with limited feedback," Global Telecommunications Conference,2004, vol.1, pp214-218, Nov.2004
[7]Imran Mushtaq, Andrew Logothetis, Bo Goransson, Mats Viberg, "3G Transmit diversity and inter-cell Interference Suppression using Multiple Antenna Terminals," VTC,2002, vol.4, pp2512-2516, Sept.2002
[8]R. S. Blum, "MIMO Capacity with Interference," IEEE J. Select. Areas Communication, vol.21, NO.5, pp793-801, June 2003
[9]T. M. Cover and J. A. Thomas, Elements of Information Theory, New York, USA,: John Wiley,1991