MIMO-OFDM系统中的空时编码技术的研究
摘要
作为4G的一项核心,MIMO-OFDM已经被越来越多的人所关注,它可以在复杂的无线通信环境中,在不增加频谱带宽和额外的发射功率的前提下,极大的提高无线通信系统的传输速率和可靠性。空时编码技术是实现MIMO-OFDM系统性能的一种有效的方式,本文在对国内相关研究的基础上,主要是围绕着空时编码进行了分析研究。
首先,阐述了在现代通信中所面临的困境以及MIMO技术与传统的通信技术相比的巨大优势及其原因,并且对多输入多输出(Multiple Input Multiple Output,MIMO)的天线技术和正交频分复用(Orthogonal Frequency Division Multiplexing, OFDM)技术分别进行了分析研究。其次,在MIMO系统模型建立的基础上介绍了几种常用的空时编码技术,分析、比较了它们的优缺点,针对Alamouti的经典算法做了进一步的研究和拓展,并且对编码后和未编码的OFDM系统仿真结果进行了分析和比较,仿真结果表明,编码后的OFDM系统的可靠性和误码率都得到了很大的改善。然后,针对MIMO技术在宽带情况下受限的问题,将MIMO和OFDM结合了起来。对MIMO-OFDM系统中的空时分组编码和空时频分组编码(Space-time frequency block code, STFBC)技术进行了理论分析,并且与OFDM系统相结合,从误码率的角度进行仿真分析,在误码率为10-2时,编码后的系统相对于STBC-OFDM系统所需信噪比约下降3dB,提高了系统的可靠性。
As one of the most important technologies, MIMO-OFDM has attracted a lot of attention. It can enormously improve the data-transmission rate and the reliability in complex environments of wireless communication without increasing the spectrum bandwidth and the transmission power. Space-time code is a way which can implement the performance of the MIMO-OFDM. Some work has been done according to the researches at home and abroad.
Firstly, difficulties faced by modern communication and the advantages of MIMO compared with traditional communication technologies have been described. The Multiple Input Multipe Output (MIMO) antenna technology and Orthogonal Frequency Division Multiplexing (OFDM) technology are analysised and researched separately. Secondly, several common code techniques have been introduced based on the established MIMO system. There are some analysis and comparisons between them. To Alamouti classical algorithm research and development, the code and not code of OFDM systems simulation results are analyzed and compared, the simulation results show that the code of the reliability of the system of OFDM after all got the bit error rate and greatly improved. Finally, as the limits of MIMO in the broadband, MIMO and OFDM are combined. After the theoretical analysis of STBC-OFDM and STFBC-OFDM, from the point of view of ber simulation analysis, the bit error rate in 10-2, coding system relative to STBC-OFDM system required signal-to-noise ratio of about 3 dB decline, improve the reliability of system.
首先,阐述了在现代通信中所面临的困境以及MIMO技术与传统的通信技术相比的巨大优势及其原因,并且对多输入多输出(Multiple Input Multiple Output,MIMO)的天线技术和正交频分复用(Orthogonal Frequency Division Multiplexing, OFDM)技术分别进行了分析研究。其次,在MIMO系统模型建立的基础上介绍了几种常用的空时编码技术,分析、比较了它们的优缺点,针对Alamouti的经典算法做了进一步的研究和拓展,并且对编码后和未编码的OFDM系统仿真结果进行了分析和比较,仿真结果表明,编码后的OFDM系统的可靠性和误码率都得到了很大的改善。然后,针对MIMO技术在宽带情况下受限的问题,将MIMO和OFDM结合了起来。对MIMO-OFDM系统中的空时分组编码和空时频分组编码(Space-time frequency block code, STFBC)技术进行了理论分析,并且与OFDM系统相结合,从误码率的角度进行仿真分析,在误码率为10-2时,编码后的系统相对于STBC-OFDM系统所需信噪比约下降3dB,提高了系统的可靠性。
As one of the most important technologies, MIMO-OFDM has attracted a lot of attention. It can enormously improve the data-transmission rate and the reliability in complex environments of wireless communication without increasing the spectrum bandwidth and the transmission power. Space-time code is a way which can implement the performance of the MIMO-OFDM. Some work has been done according to the researches at home and abroad.
Firstly, difficulties faced by modern communication and the advantages of MIMO compared with traditional communication technologies have been described. The Multiple Input Multipe Output (MIMO) antenna technology and Orthogonal Frequency Division Multiplexing (OFDM) technology are analysised and researched separately. Secondly, several common code techniques have been introduced based on the established MIMO system. There are some analysis and comparisons between them. To Alamouti classical algorithm research and development, the code and not code of OFDM systems simulation results are analyzed and compared, the simulation results show that the code of the reliability of the system of OFDM after all got the bit error rate and greatly improved. Finally, as the limits of MIMO in the broadband, MIMO and OFDM are combined. After the theoretical analysis of STBC-OFDM and STFBC-OFDM, from the point of view of ber simulation analysis, the bit error rate in 10-2, coding system relative to STBC-OFDM system required signal-to-noise ratio of about 3 dB decline, improve the reliability of system.
引文
[1]姚引娣.第四代移动通信系统及其关键技术.西安邮电学院学报[J],2007,12(5)：25-29.
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[4]万仲宇.LDPC码在无线光通信中的应用研究[D].长春理工大学,2010.
[5]刘朝阳.LTE下行链路仿真平台设计实现及物理层关键技术分析[D].西安科技大学,2011.
[6]汪裕民OFDM关键技术与应用[M].机械工业出版社,2007.
[7]陈刘琦.MIMO-OFDM系统及其关键技术[D].移动通信,2008(14).
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[9]朱凌燕.宽带无线系统中空时编码关键技术的研究[D].上海交通大学,2006.
[10]Telecommunications, Beijing 100876, China;Analysis on Orthogonal-Code Repeat Transmission for MIMO-OFDM System[A];中国通信学会第五届学术年会论文集[C]；2008年
[11]薛明MIMO-OFDM编码技术研究.哈尔滨工程大学[J],2010年3月.
[12]王晓海.空时编码技术[M].机械工业出版社,2004.
[13]程明康.MIMO-OFDM技术在WiMAX多基站协作通信中的应用研究[J].北京邮电大学,2009.
[14]M.K.Simon, M.-S.Alouini. Digital Communication over Fading Channels:Aunified Approach to Performance Analysis [J], New York:Wiley,2000.
[15]谢赛锦.无线网络中的协作分集：原理和应用[J].西安电子科技大学,2008.
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[17]A.F.Naguib and R.Calderbank, Space-Time coding and signal processing for high data rate woreless communications [J]. IEEE Signal Processing Magazine, vol.17, no.3, pp.76-92, Mar.2000.
[18]李小楠.衰落信道下SIMO系统的ADOATDOA组合定位及其系统性能分析[D].中国海洋大学,2009.
[19]ALAMOUTISM. A simple transmit diversity technique for wireless communication [J]. IEEEJ Select Areas Commun,1998(16):1451-1458.
[20]V.Tarokh, N.Seshadri, A.R.Calderbank. Space-Time coding for High Data Rate Wirless Communication:Performance Criterion and Code Construction [J], IEEE Transactions on Information Theory, March 1998,44(2):744-765.
[21]乔喜梅.多输入多输出多载波CDMA系统性能比较研究[D].北京交通大学,2007.
[22]王维.MIMO无线通信系统的预处理及检测技术研究[D].上海交通大学,2008.
[23]于莉娜.MIMO通信系统的空时编码和信道估计技术研究与实现.国防科学技术大学[D],2010.
[24]陈康.MIMO M2M系统中空时编码的分析与研究[D].武汉理工大学,2009.
[25]S.Verdu, Multiuser Detection [J], Cambridge University Press,1998.
[26]李小梅.V-BLAST中硬判反馈迭代和检测研究[D].南京航空航天大学,2007.
[27]毛剑.基于MIMO-OFDM系统的均衡技术研究[J].长春理工大学,2010.
[28]吴素文,无线协作网络中的节点选择问题研究[J].中国科学技术大学,2010.
[29]张有方.基于IEEE802.11a标准的OFDM系统同步算法研究[J].重庆大学,2007.
[30]梁晓燕.MIMO-OFDM系统中降低PAPR方法的研究[D].成都信息工程学院,2007.
[31]Damenmo, Abedkm, Belfiorejc. Digital algebraic space-time block codes [J]. IEEE Trans inform Theory.
[32]王顶,赵宏锋,王永生.STBC—OFDM系统的性能分析及仿真[J].无线通信技术,2006年4期.
[33]刘雪飞,胖为证,张建华,贾宝.基于空时频编码的OFDM系统设计[D].哈尔滨工程大学,2008年2月.
[34]Sutok, Ohtsukit. Space-Time-Frequency Block Codes over Frequency Selective Fading Channels [J]. IEEE Trans commun,2004, E87-B(7):1939-1945.
[35]张宇.三大技术力拓全球无线电疆域[J].上海信息化,2010年5期.
[36]NEERV, PRASADR. OFDM for wireless multimedia communications [M]. England Artech House,2000,16-50.
[37]LEEKF, WILLIAMSDB. A space-time coded transmitter diversity technique for frequency selective fading channels [C]. IEEE Sensor Array and Multi channel Signal Processing Work shop Cambrige MA,2000,149-152.
[38]LIUZ, XINY, GIANNAKISG. Space-time-frequency coded OFDM over frequency selective fading channels [J]. IEEE Trans Signal Processing,2002,50(10):2465-2476.
[39]郭旭东,张春业,曹建海MIMO-OFDM无线局域网的性能分析及其关键技术[J]重庆邮电学院学报自然科学版,2005,17(2)：180-183.
[40]HAYKINS, MOHERM. Modem wireless communications [M]. America Pearson Prentice Hall,2005,379-388.
[41]RAPPAPORTTS. Wireless communications principles and practice [M].2nd, America Prentice Hall PTR,2002,197-210.
[42]兰洋,程时听.结合STBC的一种分层空时编码结构模型.电路与系统学报[J].2004, 9(1).
[43]Agrawal D, Tarokh V, and Naguib A. Space-time coded OFDM for high data-rate wireless communication over wideband channels [J]. Proc.Veh. Technol. Conf.Ottawa, Canada,1998:2232-2236P.
[44]Lu Ben and Wang Xiaodong. Space-Time Code Design in OFDM Systems [J]. IEEE GLOBECOM, San Francisco,2000(2):1000-1004P.
[2]武霞.亢军贤.薄征.全IP第四代移动通信系统研究进展与关键技术[J].甘肃科技.2008,24(10)：26-28.
[3]王军选.第四代移动通信系统与其关键技术研究[M].电信科学.2009,3(25)90-93.
[4]万仲宇.LDPC码在无线光通信中的应用研究[D].长春理工大学,2010.
[5]刘朝阳.LTE下行链路仿真平台设计实现及物理层关键技术分析[D].西安科技大学,2011.
[6]汪裕民OFDM关键技术与应用[M].机械工业出版社,2007.
[7]陈刘琦.MIMO-OFDM系统及其关键技术[D].移动通信,2008(14).
[8]张军,丽娜.现代通信原理与技术[M].西安电子科技大学出版社,2002-1.
[9]朱凌燕.宽带无线系统中空时编码关键技术的研究[D].上海交通大学,2006.
[10]Telecommunications, Beijing 100876, China;Analysis on Orthogonal-Code Repeat Transmission for MIMO-OFDM System[A];中国通信学会第五届学术年会论文集[C]；2008年
[11]薛明MIMO-OFDM编码技术研究.哈尔滨工程大学[J],2010年3月.
[12]王晓海.空时编码技术[M].机械工业出版社,2004.
[13]程明康.MIMO-OFDM技术在WiMAX多基站协作通信中的应用研究[J].北京邮电大学,2009.
[14]M.K.Simon, M.-S.Alouini. Digital Communication over Fading Channels:Aunified Approach to Performance Analysis [J], New York:Wiley,2000.
[15]谢赛锦.无线网络中的协作分集：原理和应用[J].西安电子科技大学,2008.
[16]M.K.Simoin and M.-S.Alouini, Digital Communication over Fading Channels [J]:A Unified Aprroach to Performance Analysis, John wiley&Sons,2000.
[17]A.F.Naguib and R.Calderbank, Space-Time coding and signal processing for high data rate woreless communications [J]. IEEE Signal Processing Magazine, vol.17, no.3, pp.76-92, Mar.2000.
[18]李小楠.衰落信道下SIMO系统的ADOATDOA组合定位及其系统性能分析[D].中国海洋大学,2009.
[19]ALAMOUTISM. A simple transmit diversity technique for wireless communication [J]. IEEEJ Select Areas Commun,1998(16):1451-1458.
[20]V.Tarokh, N.Seshadri, A.R.Calderbank. Space-Time coding for High Data Rate Wirless Communication:Performance Criterion and Code Construction [J], IEEE Transactions on Information Theory, March 1998,44(2):744-765.
[21]乔喜梅.多输入多输出多载波CDMA系统性能比较研究[D].北京交通大学,2007.
[22]王维.MIMO无线通信系统的预处理及检测技术研究[D].上海交通大学,2008.
[23]于莉娜.MIMO通信系统的空时编码和信道估计技术研究与实现.国防科学技术大学[D],2010.
[24]陈康.MIMO M2M系统中空时编码的分析与研究[D].武汉理工大学,2009.
[25]S.Verdu, Multiuser Detection [J], Cambridge University Press,1998.
[26]李小梅.V-BLAST中硬判反馈迭代和检测研究[D].南京航空航天大学,2007.
[27]毛剑.基于MIMO-OFDM系统的均衡技术研究[J].长春理工大学,2010.
[28]吴素文,无线协作网络中的节点选择问题研究[J].中国科学技术大学,2010.
[29]张有方.基于IEEE802.11a标准的OFDM系统同步算法研究[J].重庆大学,2007.
[30]梁晓燕.MIMO-OFDM系统中降低PAPR方法的研究[D].成都信息工程学院,2007.
[31]Damenmo, Abedkm, Belfiorejc. Digital algebraic space-time block codes [J]. IEEE Trans inform Theory.
[32]王顶,赵宏锋,王永生.STBC—OFDM系统的性能分析及仿真[J].无线通信技术,2006年4期.
[33]刘雪飞,胖为证,张建华,贾宝.基于空时频编码的OFDM系统设计[D].哈尔滨工程大学,2008年2月.
[34]Sutok, Ohtsukit. Space-Time-Frequency Block Codes over Frequency Selective Fading Channels [J]. IEEE Trans commun,2004, E87-B(7):1939-1945.
[35]张宇.三大技术力拓全球无线电疆域[J].上海信息化,2010年5期.
[36]NEERV, PRASADR. OFDM for wireless multimedia communications [M]. England Artech House,2000,16-50.
[37]LEEKF, WILLIAMSDB. A space-time coded transmitter diversity technique for frequency selective fading channels [C]. IEEE Sensor Array and Multi channel Signal Processing Work shop Cambrige MA,2000,149-152.
[38]LIUZ, XINY, GIANNAKISG. Space-time-frequency coded OFDM over frequency selective fading channels [J]. IEEE Trans Signal Processing,2002,50(10):2465-2476.
[39]郭旭东,张春业,曹建海MIMO-OFDM无线局域网的性能分析及其关键技术[J]重庆邮电学院学报自然科学版,2005,17(2)：180-183.
[40]HAYKINS, MOHERM. Modem wireless communications [M]. America Pearson Prentice Hall,2005,379-388.
[41]RAPPAPORTTS. Wireless communications principles and practice [M].2nd, America Prentice Hall PTR,2002,197-210.
[42]兰洋,程时听.结合STBC的一种分层空时编码结构模型.电路与系统学报[J].2004, 9(1).
[43]Agrawal D, Tarokh V, and Naguib A. Space-time coded OFDM for high data-rate wireless communication over wideband channels [J]. Proc.Veh. Technol. Conf.Ottawa, Canada,1998:2232-2236P.
[44]Lu Ben and Wang Xiaodong. Space-Time Code Design in OFDM Systems [J]. IEEE GLOBECOM, San Francisco,2000(2):1000-1004P.