基于覆盖延展的高速业务新型切换算法
摘要
4G系统支持多种业务类型,存在多种业务的覆盖,一般业务速率越高,其覆盖范围越小。高速业务的覆盖范围比较小,很难保证覆盖的连续性,致使承载该业务的用户往往还没有到达小区的切换区域就产生掉话。
OFDMA系统是典型的4G系统,本文首先介绍了OFDMA系统的原理、多址方式及其无线资源管理技术。对于OFDMA系统,高速率业务通常占用系统资源较多,会对系统的动态特性造成很大影响,造成切换期间和切换之后的一段时间内系统传输性能的下降。目前在多业务共存的环境下,关于多业务切换算法的文章主要关注不同QoS业务的等级划分和切换排队算法,并没有关注未来多业务、多QoS共存的条件下,高速业务用户由于覆盖不连续而造成切换失败的问题。
其次,本文针对以上切换算法的不足提出了新型的切换算法:基于覆盖延展的高速业务新型切换算法。该算法在降低信源编码速率的同时结合弱子载波去除策略(Faint Sub-carrier Elimination Strategy,FSES),动态的调整用户子载波的分配,使资源利用更加灵活,延展了高速业务的覆盖面积,形成“暂态覆盖”;采用“暂态切换QoS”,减少切换对目标小区的影响,使高速业务用户能够平滑切换。
最后本文设计并实现了OFDMA的系统级仿真平台,并在此仿真平台的基础上,通过仿真分析对本文提出的基于覆盖延展的高速业务新型切换算法性能进行了评估。仿真结果表明,新型的切换算法能够维持高速业务用户通话连续性,降低切换掉话率和接入阻塞率,提高资源利用率,优化了OFDMA系统的整体性能。
4G supports various types of services. Different services have different coverage. The coverage of high-speed data service is smaller than that of low-speed data service, which can not guarantee continuous coverage and usually makes the high-speed data service users occur dropping before reaching the handover area.
OFDMA is typical 4G system. First, this paper introduces OFDMA system theory, multiple access schemes and radio resource management (RRM) technologies; High-speed data service usually occupies more system resource in 4G system, which will bring greatly impact on dynamic characteristics of system, cause system performance to decline during and after handover process. Existing handover algorithms for multiple services are mainly concerned on classification of services of different QoS and handover with queuing, ignoring the problem of handover failure caused by the discontinuous coverage of high-speed data service in the condition of the coexistence of multiple services and QoS classes.
Second, considering the disadvantages of present handover algorithms, this paper proposes a new OFDMA handover algorithm: A Coverage-based Handover Algorithm for High-speed Data Service. The new handover algorithm reduces source rate and adopts FSES (Faint Sub-carrier Elimination Strategy) to adjust the sub-carrier allocation and make the resource allocation more flexible, which extends the coverage of high-speed data service and makes users acquire "transient coverage". Meanwhile, the new algorithm utilizes the "transient handover QoS" to reduce the handover effect to target cell for high-speed data service users and make these users acquire smooth handover. Last, this paper designs and completes the OFDMA system level simulation platform. Based on the platform, the new handover algorithm performance is evaluated by simulation analysis. The simulation results shows that the new algorithm can improve the whole system performance, reduce the handover dropping probability and new call blocking probability, enhance the resource utilization ratio.
OFDMA系统是典型的4G系统,本文首先介绍了OFDMA系统的原理、多址方式及其无线资源管理技术。对于OFDMA系统,高速率业务通常占用系统资源较多,会对系统的动态特性造成很大影响,造成切换期间和切换之后的一段时间内系统传输性能的下降。目前在多业务共存的环境下,关于多业务切换算法的文章主要关注不同QoS业务的等级划分和切换排队算法,并没有关注未来多业务、多QoS共存的条件下,高速业务用户由于覆盖不连续而造成切换失败的问题。
其次,本文针对以上切换算法的不足提出了新型的切换算法:基于覆盖延展的高速业务新型切换算法。该算法在降低信源编码速率的同时结合弱子载波去除策略(Faint Sub-carrier Elimination Strategy,FSES),动态的调整用户子载波的分配,使资源利用更加灵活,延展了高速业务的覆盖面积,形成“暂态覆盖”;采用“暂态切换QoS”,减少切换对目标小区的影响,使高速业务用户能够平滑切换。
最后本文设计并实现了OFDMA的系统级仿真平台,并在此仿真平台的基础上,通过仿真分析对本文提出的基于覆盖延展的高速业务新型切换算法性能进行了评估。仿真结果表明,新型的切换算法能够维持高速业务用户通话连续性,降低切换掉话率和接入阻塞率,提高资源利用率,优化了OFDMA系统的整体性能。
4G supports various types of services. Different services have different coverage. The coverage of high-speed data service is smaller than that of low-speed data service, which can not guarantee continuous coverage and usually makes the high-speed data service users occur dropping before reaching the handover area.
OFDMA is typical 4G system. First, this paper introduces OFDMA system theory, multiple access schemes and radio resource management (RRM) technologies; High-speed data service usually occupies more system resource in 4G system, which will bring greatly impact on dynamic characteristics of system, cause system performance to decline during and after handover process. Existing handover algorithms for multiple services are mainly concerned on classification of services of different QoS and handover with queuing, ignoring the problem of handover failure caused by the discontinuous coverage of high-speed data service in the condition of the coexistence of multiple services and QoS classes.
Second, considering the disadvantages of present handover algorithms, this paper proposes a new OFDMA handover algorithm: A Coverage-based Handover Algorithm for High-speed Data Service. The new handover algorithm reduces source rate and adopts FSES (Faint Sub-carrier Elimination Strategy) to adjust the sub-carrier allocation and make the resource allocation more flexible, which extends the coverage of high-speed data service and makes users acquire "transient coverage". Meanwhile, the new algorithm utilizes the "transient handover QoS" to reduce the handover effect to target cell for high-speed data service users and make these users acquire smooth handover. Last, this paper designs and completes the OFDMA system level simulation platform. Based on the platform, the new handover algorithm performance is evaluated by simulation analysis. The simulation results shows that the new algorithm can improve the whole system performance, reduce the handover dropping probability and new call blocking probability, enhance the resource utilization ratio.
引文
[1]LIU Guangyi,ZHANG Jianhua,ZHANG Ping,Further Vision on TD-SCDMA Evolution,IEEE2005,Page(s):143-147
[2]Guangyi Liu,Jianhua Zhang,Ping Zhang,Ying Wang,Xiantao Liu,and Shuang Li,Evolution Map from TD-SCDMA to FUTURE B3G TDD,IEEE 2006,Page(s):54-61
[3]Erik B.Dahlman、Yu-Chuen Jou,FURTHER EVOLUTION OF 3G RADIO ACCESS,IEEE 2006,Page(s):34-36
[4]Hannes Ekstrom,Anders Furuskar,Jonas Karlsson,Michael Meyer,Stefan Parkvall,Johan Torsner,and Mattias Wahlqvist,Technical Solutions for the 3G Long-Term Evolution,IEEE 2006,Page(s):38-45
[5]Gholamreza Parsaee,Abdulrahman Yarali,OFDMA for the 4/sup th/generation cellular networks,IEEE 2004,Page(s):2325-2330
[6]沈嘉,3GPP LTE核心技术及标准化进展,移动通信,2006.4页45-49
[7]王文博,郑侃,宽带无线通信OFDM技术,人民邮电出版社,2003
[8]侯自强,从WiMAX到LTE不同宽带无线接入技术殊途同归,电信科学2005年第10期,页18-21
[9]Guangyi Liu,Jianhua Zhang,Ping Zhang,Ying Wang,Xiantao Liu,and Shuang Li,Evolution Map from TD-SCDMA to FUTURE B3G TDD,IEEE 2006,Page(s):54-61
[10]Erik B.Dahlman、Yu-Chuen Jou,FURTHER EVOLUTION OF 3G RADIO ACCESS,IEEE2006,Page(s):34-36
[11]沈嘉,3GPP LTE核心技术及标准化进展,移动通信,2006.4页45-49
[12]Luke T.H.Lee,ChungoJu Chang,Yih-Shen Chen,and Scott Shen,A Utility-Approached Radio Resource Allocation Algorithm for Downlink in OFDMA Cellular Systems,IEEE 2005
[13]王文博,郑侃,宽带无线通信OFDM技术,人民邮电出版社,2003
[14]Guoqing Li and Hui Liu,On the Optimality of the OFDMA Network,IEEE 2005,Page(s):438-440
[15]王文博,郑侃,宽带无线通信OFDM技术,人民邮电出版社,2003
[16]张荣涛,谢显中,OFDM几种多址接入技术的分析,信息技术,2006年第5期,页59-62
[17]陈臣,马晓婷,刘乃安,OFDMA无线宽带接入系统简介及性能仿真分析,电力系统通信,第26卷第148期,页42-44
[18]X.Cai,S.Zhou,and G.B.Giannakis,Group-Orthogonal Multicarrier CDMA,IEEE 2004,Page(s):90-99
[19]James Gross,Hans-Florian Geerdes,Holger Karl and dam Wolisz,Performance Analysis of Dynamic OFDMA Systems With Inband Signaling,IEEE 2006,Page(s):427-436
[20]Jianfeng Qiang,Ping Zhang,An Efficient Multiple Access Scheme for Dynami Subband Allocation in OFDMA System,IEEE 2005,Page(s):1046-1049
[21]张布战,陈臣,马晓婷,子载波交织分配的OFDMA系统,信息技术,2005年第6期,页21-23
[22]Y.Peng,A.Doufexi,S.Armour and J.McGeehan,An Investigation of Dynamic Sub-carrier Allocation in OFDMA Systems,IEEE 2005
[23]Kanghee Kim,Hongku Kang and Kiseon Kim,Providing Quality of Service in Adaptive Resource Allocation for OFDMA Systems,IEEE 2004,Page(s):1612-1615
[24]Yinglin Xu,J.Weng,and Tho Le-Ngoc,Adaptive Tone Diversity for OFDMA in Broadband Wireless Communications,IEEE 2004,Page(s):1594-1597
[25]Young-June Choi,Suho Park,and Saewoong Bahk,Multichannel Random Access in OFDMAWireless Networks,IEEE 2006,Page(s):603-613
[26]3GPP,"Radio Resource Control(RRC)",TS 25.331,June 2005
[27]孙立新,尤肖虎,张萍等,第三代移动通信技术,人民邮电出版社,2001
[28]王莹,张平,无线资源管理,北京邮电大学出版社,2005
[29]Alex Hills,Bob Friday,Radio Resource Management in Wireless LANs,IEEE 2004,Page(s):9-14
[30]Per Magnusson,Johan Lundsjo,Joachim Sachs,Pontus Wallentin,Radio Resource Management Distribution in a Beyond 3G Multi-Radio Access Architecture,IEEE 2004,Page(s):3472-3477
[31]Hano Wang,Choong Chae Woo and Daesik Hong,A New Subcarrier Oriented Handover Scheme in Downlink OFDMA Cellular Systems,IEEE 2005,Page(s):1618-1622
[32]802.16e-2005
[33]Doo Hwan Lee,Kyandoghere Kyamakya and Jean Paul Umondi,Fast Handover Algorithm for IEEE 802.16e Broadband Wireless Access System
[34]Sik Choi,Gyung-Ho Hwang,Taesoo Kwon,Ae-Ri Lim,and Dong-Ho Cho,Fast Handover Scheme for Real-Time Downlink Services in IEEE 802.16e BWA System,IEEE 2005
[35]Gabriele Lupo,Roberto Cautelier,Maria-Gabriella Di Benedetto,Francesco Malena,Dynamic Resource Allocation with a Soft Handover Procedure for Application in a Broadband System,IEEE1999,Page(s):2111-2115
[36]Kin K.Leung,Sayandev Mukherjee and George E.Rittenhouse,Mobility Support for IEEE 802.16d Wireless Networks,IEEE 2005,Page(s):1446-1452
[37]Il-Hee Shin,Chae-Woo Lee,A QoS Guaranteed Fast Handoff Algorithm for Wireless LAN,IEEE 2004,Page(s):3827-3832
[38]Andrea Goldsmith,Wireless Communications,Cambridge,2005.
[39]3GPP TS 26.071 V3.0.1-1999,AMR speech codec;general description[S].
[40]Wu D,Hou Y,Zhang Y,Scalable Video Coding and Transport Over Broad-band Wireless Networks[J].Proceedings of the IEEE,2001,89(1):6-20.
[41]Lajos Hanzo,et al,Video Compression and Communications,John Wiley & Sons Ltd,2007.
[42]Wu Junli,Teng Yong,Yin Changchuan,On Performance of Multiple Access for OFDM Transmission Technique in Rayleigh Fading Channel[A].ICCT 2003[C],Beijing,2003.4
[43]孙黎辉,3G无线网络系统级仿真与网络规划[J],移动通信,2006(08)。
[44]杨大成等,移动传播环境理论基础·分析方法和建模技术,机械工业出版社,2003
[2]Guangyi Liu,Jianhua Zhang,Ping Zhang,Ying Wang,Xiantao Liu,and Shuang Li,Evolution Map from TD-SCDMA to FUTURE B3G TDD,IEEE 2006,Page(s):54-61
[3]Erik B.Dahlman、Yu-Chuen Jou,FURTHER EVOLUTION OF 3G RADIO ACCESS,IEEE 2006,Page(s):34-36
[4]Hannes Ekstrom,Anders Furuskar,Jonas Karlsson,Michael Meyer,Stefan Parkvall,Johan Torsner,and Mattias Wahlqvist,Technical Solutions for the 3G Long-Term Evolution,IEEE 2006,Page(s):38-45
[5]Gholamreza Parsaee,Abdulrahman Yarali,OFDMA for the 4/sup th/generation cellular networks,IEEE 2004,Page(s):2325-2330
[6]沈嘉,3GPP LTE核心技术及标准化进展,移动通信,2006.4页45-49
[7]王文博,郑侃,宽带无线通信OFDM技术,人民邮电出版社,2003
[8]侯自强,从WiMAX到LTE不同宽带无线接入技术殊途同归,电信科学2005年第10期,页18-21
[9]Guangyi Liu,Jianhua Zhang,Ping Zhang,Ying Wang,Xiantao Liu,and Shuang Li,Evolution Map from TD-SCDMA to FUTURE B3G TDD,IEEE 2006,Page(s):54-61
[10]Erik B.Dahlman、Yu-Chuen Jou,FURTHER EVOLUTION OF 3G RADIO ACCESS,IEEE2006,Page(s):34-36
[11]沈嘉,3GPP LTE核心技术及标准化进展,移动通信,2006.4页45-49
[12]Luke T.H.Lee,ChungoJu Chang,Yih-Shen Chen,and Scott Shen,A Utility-Approached Radio Resource Allocation Algorithm for Downlink in OFDMA Cellular Systems,IEEE 2005
[13]王文博,郑侃,宽带无线通信OFDM技术,人民邮电出版社,2003
[14]Guoqing Li and Hui Liu,On the Optimality of the OFDMA Network,IEEE 2005,Page(s):438-440
[15]王文博,郑侃,宽带无线通信OFDM技术,人民邮电出版社,2003
[16]张荣涛,谢显中,OFDM几种多址接入技术的分析,信息技术,2006年第5期,页59-62
[17]陈臣,马晓婷,刘乃安,OFDMA无线宽带接入系统简介及性能仿真分析,电力系统通信,第26卷第148期,页42-44
[18]X.Cai,S.Zhou,and G.B.Giannakis,Group-Orthogonal Multicarrier CDMA,IEEE 2004,Page(s):90-99
[19]James Gross,Hans-Florian Geerdes,Holger Karl and dam Wolisz,Performance Analysis of Dynamic OFDMA Systems With Inband Signaling,IEEE 2006,Page(s):427-436
[20]Jianfeng Qiang,Ping Zhang,An Efficient Multiple Access Scheme for Dynami Subband Allocation in OFDMA System,IEEE 2005,Page(s):1046-1049
[21]张布战,陈臣,马晓婷,子载波交织分配的OFDMA系统,信息技术,2005年第6期,页21-23
[22]Y.Peng,A.Doufexi,S.Armour and J.McGeehan,An Investigation of Dynamic Sub-carrier Allocation in OFDMA Systems,IEEE 2005
[23]Kanghee Kim,Hongku Kang and Kiseon Kim,Providing Quality of Service in Adaptive Resource Allocation for OFDMA Systems,IEEE 2004,Page(s):1612-1615
[24]Yinglin Xu,J.Weng,and Tho Le-Ngoc,Adaptive Tone Diversity for OFDMA in Broadband Wireless Communications,IEEE 2004,Page(s):1594-1597
[25]Young-June Choi,Suho Park,and Saewoong Bahk,Multichannel Random Access in OFDMAWireless Networks,IEEE 2006,Page(s):603-613
[26]3GPP,"Radio Resource Control(RRC)",TS 25.331,June 2005
[27]孙立新,尤肖虎,张萍等,第三代移动通信技术,人民邮电出版社,2001
[28]王莹,张平,无线资源管理,北京邮电大学出版社,2005
[29]Alex Hills,Bob Friday,Radio Resource Management in Wireless LANs,IEEE 2004,Page(s):9-14
[30]Per Magnusson,Johan Lundsjo,Joachim Sachs,Pontus Wallentin,Radio Resource Management Distribution in a Beyond 3G Multi-Radio Access Architecture,IEEE 2004,Page(s):3472-3477
[31]Hano Wang,Choong Chae Woo and Daesik Hong,A New Subcarrier Oriented Handover Scheme in Downlink OFDMA Cellular Systems,IEEE 2005,Page(s):1618-1622
[32]802.16e-2005
[33]Doo Hwan Lee,Kyandoghere Kyamakya and Jean Paul Umondi,Fast Handover Algorithm for IEEE 802.16e Broadband Wireless Access System
[34]Sik Choi,Gyung-Ho Hwang,Taesoo Kwon,Ae-Ri Lim,and Dong-Ho Cho,Fast Handover Scheme for Real-Time Downlink Services in IEEE 802.16e BWA System,IEEE 2005
[35]Gabriele Lupo,Roberto Cautelier,Maria-Gabriella Di Benedetto,Francesco Malena,Dynamic Resource Allocation with a Soft Handover Procedure for Application in a Broadband System,IEEE1999,Page(s):2111-2115
[36]Kin K.Leung,Sayandev Mukherjee and George E.Rittenhouse,Mobility Support for IEEE 802.16d Wireless Networks,IEEE 2005,Page(s):1446-1452
[37]Il-Hee Shin,Chae-Woo Lee,A QoS Guaranteed Fast Handoff Algorithm for Wireless LAN,IEEE 2004,Page(s):3827-3832
[38]Andrea Goldsmith,Wireless Communications,Cambridge,2005.
[39]3GPP TS 26.071 V3.0.1-1999,AMR speech codec;general description[S].
[40]Wu D,Hou Y,Zhang Y,Scalable Video Coding and Transport Over Broad-band Wireless Networks[J].Proceedings of the IEEE,2001,89(1):6-20.
[41]Lajos Hanzo,et al,Video Compression and Communications,John Wiley & Sons Ltd,2007.
[42]Wu Junli,Teng Yong,Yin Changchuan,On Performance of Multiple Access for OFDM Transmission Technique in Rayleigh Fading Channel[A].ICCT 2003[C],Beijing,2003.4
[43]孙黎辉,3G无线网络系统级仿真与网络规划[J],移动通信,2006(08)。
[44]杨大成等,移动传播环境理论基础·分析方法和建模技术,机械工业出版社,2003