中继通信模型下基于码合并的协作ARQ技术研究
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摘要
为了对抗无线信道的衰落特性,各种分集技术在近年来受到广泛关注。协作分集技术通过中继节点协助源节点发送数据,提高数据传输的可靠性。在此基础上,接收端进行码合并,进一步为系统带来了额外的时间分集增益。因此研究中继模型下的带码合并协作ARQ协议具有重要的理论价值和研究意义。
论文首先对放大转发(AF, Amplify and Forward)中继、译码转发(DF,Decode and Forward)中继通信模型进行分析,并对协作ARQ技术以及码合并技术基本原理进行讨论得到了适用于不同协作ARQ协议的码合并技术。接着论文在两种中继模型下对带码合并的Ⅰ类协作ARQ以及DF中继下带码合并的Ⅲ类协作ARQ协议进行了性能分析。研究结果表明,码合并的引入可以增加系统的分集阶数,增加的系数与合并的编码分组数相关。随后文章讨论了中继位置对协作ARQ系统性能的影响,在DF中继下低信噪比时宜选择位于中间位置的中继节点,高信噪比时,宜选择离目的节点更近的中继节点；对于AF中继下的带码合并的协作ARQ系统来说,离源节点更近的中继节点往往可以获得更好的性能。最后我们分析了多中继下带码合并的协作ARQ系统性能,在DF中继下多一个中继参与传输的系统性能约等价于在单中继时系统多传输一次的性能。而在AF中继下,低信噪比时,中继数目的增多反而引起系统性能的下降；高信噪比时,中继数目的增多可以给系统带来性能的提升。因此,我们可以根据具体的信道条件来选择参与传输的中继数目。
In order to counteract the fading of wireless channel, a variety of diversity techniques have received great attention in recent years. Cooperative diversity improves the reliability of data transmission by the way of relay node's assisting data tranmission of source node. On above basis, the system gets extra extra time diversity gain with code combining at the destination. Therefore, it has great theoretic and research value to research on cooperative ARQ with code combining in relay communication mode.
Firstly, the Ampllified-and-Forward and Decode-and-Forward relay model is analyzed. With the fundamental principle discussion of cooperative ARQ and code combining, we obtain the code combining techniques for different ARQ protocols. Then, the performance of typeⅠcooperative ARQ with code combining in DF and AF relay communications and typeⅢcooperative ARQ in DF relay communications are analyzed. The results of the study show that the introduction of code combining brings an increase in diversity order and increased coefficient is relevant to code cluster number. With study of relay location's influence to ARQ system performance, we obtain below principles, the middle relay should be choosen in DF relay communicaitions with low SNR and the relay closer to destination node should be choosen; Cooperative ARQ system with AF relay can obtain better performance by choosing relay closer to source node. At last, the performance of cooperative ARQ system with code combining in multi-relay cooperative communication is analyzed. In DF relay communications, system performance with one more relay is equivalent to system performance with one more retransmission in single-relay. While in AF relay communicaitions the system performance will be decreased at low SNR and improved at high SNR with relay number increasing. Therefore, we can select transmission relay number according to the specific channel conditions.
论文首先对放大转发(AF, Amplify and Forward)中继、译码转发(DF,Decode and Forward)中继通信模型进行分析,并对协作ARQ技术以及码合并技术基本原理进行讨论得到了适用于不同协作ARQ协议的码合并技术。接着论文在两种中继模型下对带码合并的Ⅰ类协作ARQ以及DF中继下带码合并的Ⅲ类协作ARQ协议进行了性能分析。研究结果表明,码合并的引入可以增加系统的分集阶数,增加的系数与合并的编码分组数相关。随后文章讨论了中继位置对协作ARQ系统性能的影响,在DF中继下低信噪比时宜选择位于中间位置的中继节点,高信噪比时,宜选择离目的节点更近的中继节点；对于AF中继下的带码合并的协作ARQ系统来说,离源节点更近的中继节点往往可以获得更好的性能。最后我们分析了多中继下带码合并的协作ARQ系统性能,在DF中继下多一个中继参与传输的系统性能约等价于在单中继时系统多传输一次的性能。而在AF中继下,低信噪比时,中继数目的增多反而引起系统性能的下降；高信噪比时,中继数目的增多可以给系统带来性能的提升。因此,我们可以根据具体的信道条件来选择参与传输的中继数目。
In order to counteract the fading of wireless channel, a variety of diversity techniques have received great attention in recent years. Cooperative diversity improves the reliability of data transmission by the way of relay node's assisting data tranmission of source node. On above basis, the system gets extra extra time diversity gain with code combining at the destination. Therefore, it has great theoretic and research value to research on cooperative ARQ with code combining in relay communication mode.
Firstly, the Ampllified-and-Forward and Decode-and-Forward relay model is analyzed. With the fundamental principle discussion of cooperative ARQ and code combining, we obtain the code combining techniques for different ARQ protocols. Then, the performance of typeⅠcooperative ARQ with code combining in DF and AF relay communications and typeⅢcooperative ARQ in DF relay communications are analyzed. The results of the study show that the introduction of code combining brings an increase in diversity order and increased coefficient is relevant to code cluster number. With study of relay location's influence to ARQ system performance, we obtain below principles, the middle relay should be choosen in DF relay communicaitions with low SNR and the relay closer to destination node should be choosen; Cooperative ARQ system with AF relay can obtain better performance by choosing relay closer to source node. At last, the performance of cooperative ARQ system with code combining in multi-relay cooperative communication is analyzed. In DF relay communications, system performance with one more relay is equivalent to system performance with one more retransmission in single-relay. While in AF relay communicaitions the system performance will be decreased at low SNR and improved at high SNR with relay number increasing. Therefore, we can select transmission relay number according to the specific channel conditions.
引文
[1]Foschini GJ. And Gans M.J. On the limits of wireless communications in a fading Environment when using multiple antennas. Wireless Personal Communications, vol.6, no.3, pp.311-335,1998.
[2]Teiatar I.E. Capacity of multi-antenna Gaussian channels. Bell Labs Technical Memorandum,1995. IEEE Trans. Commun., vol.56.pp.743-752.
[3]Foschini G. J. Layered space-time architecture for wireless communication in a Fading environment when using multi-element antennas. Bell Labs Technical, Journal, vol.1, no.2, pp.41-59,1996.
[4]E.Telatar. Capacity of muti-antenna Gaussian channels. European Transactions on Telecommunications,vol.10,no.6,pp.585-595,Nov./Dec.1999.
[5]A. Sendonaris, E. Erkip, and B. Aazhang. User cooperation diversity, Part I:System description. IEEE Trans. Commun., vol.51, no.11, pp.1927-1938, Nov.2003.
[6]A. Sendonaris, E. Erkip, and B. Aazhang. User cooperation diversity. Part II: implementation aspects and performance analysis. IEEE Trans. Commun., vol.51, no. 11, pp.1939-1948, Nov.2003.
[7]Theodore S.Rappaport.Wireless Communications Principles and Practice.Second Edition.2004.
[8]J.N. Laneman, D.N.C. Tse, G.W. Wornell. An Efficient Protocol for Realizing Cooperative Diversity in Wireless Networks. IEEE International Symposium on Information Theory, pp.294, June 2001.
[9]Isabella Cerutti, Andrea Fumagalli, and Puja Gupta.Cooperative ARQ Protocols in Slotted Radio Networks.Technical Report UTD,EE,2005,12.
[10]Zhao.B..Valente.M.C. Practical Relay Networks:A Generalization of Hybrid-ARQ. IEEE journal on selected Areas in Communications, pp.7-18,Jan,2005,
[11]M. Dianati, X. Ling, S. Naik, and X. Shen.A Node Cooperative ARQ Scheme for Wireless Ad-Hoc Networks.IFIP Networking 2005, May 2005, pp.1418-1421.
[12]李屹,纪红,马书惠.无线Ad hoc网络中协作重传机制的改进.北京邮电大学学报,2007,30(4)：23-27.
[13]Mehrdad Dianati, Xinhua Ling, Kshirasagar Naik, and Xuemin (Sherman) Shen.Performance Analysis of the Node Cooperative ARQ Scheme for Wireless Ad-Hoc Networks.IEEE Globecom 2005,pp.3063-3067.
[14]Lingfan Weng, Ross D. Murch.Achievable Diversity-Multiplexing-Delay Tradeoff for ARQ Cooperative Broadcast Channels.IEEE Trans. on Wireless Communications,2008, vol.7,no.5,pp1828-1832.
[15]余官定,张朝阳,仇佩亮.基于合作分集的新型自动重传协议,通信学报,2007,27(12)：20-25.
[16]Poramate Tarasak, Hlaing Minn,Yong Hoon Lee. Analysis of Incremental Relaying Protocol with RCPC in Cooperative Diversity Systems. IEEE Trans.2004,vol.36,pp.2537-2541.
[17]David Chase. Code Combining-A Maximum-Likelihood Decoding Approach for Combining an Arbitrary Number of Noisy Packets. IEEE Trans.vol.com-33, No.5, may 1985.pp.385-393.
[18]Lars K.Rasmussen and Stephen B. Wicker. A comparison of Two Combining Techniques for Equal Gain, Trellis Coded Diversity Receivers. IEEE Trans.vol.44, No.2, may 1995.pp.291-295.
[19]A Diversity Combining DS/CDMA System with Convolutional Encoding and Viterbi Decoding. IEEE Trans.vol.44, No.2, may 1995.
[20]陈庆春.基于码合并的混合差错控制及相关理论研究.西南交通大学,工学博士论文,2004年3月.
[21]Qingchun Chen, Pingzhi Fan.Performance Analysis of HARQ with Code Combining in packet-oriented CDMA system.Chinese Journal of Electronics.2004, No.1,pp:168-174.
[22]Qingchun Chen, Pingzhi Fan.Performance Evaluation of Hybrid-ARQ with Code Combining over Interleaved Rayleigh Fading Channel.IEEE Trans, on Vehicular Technology,2005,54(3):1207-1214.
[23]Qingqing Zhang and Saleem A.Kassam. Hybrid ARQ with Selective Combining for Fading Channels. IEEE Journal on selected areas in communications,Vol.17,No.5, MAY 1999
[24]Julian D. Morillo-Pozo, Jorge Garcia-Vidal. A Low Coordination Overhead C-ARQ Protocol with Frame Combining.IEEE PIMRC'07,2007, pp.1-5.
[25]Wenbo Xu,Jiaru Liu,Kai Niu and Lianhai Wu.Performance Analysis of Cooperative ARQ with Code combining over Nakagami-m Fading Channels.Wireless Pers Commun.June 2009.
[26]Inhye Park and Hyungkeun Lee,Taekon Kim. The Performance Analysis of Hybrid ARQ- Ⅱ for Cooperative Communication over Wireless Channels*. IEEE International Conference on Sensor Networks, Ubiquitous, and Trustworthy Computing.pp.402-408.June 2010.
[27]T. Wang, A. Cano and J. N. Laneman. High-Performance Cooperative Demodulation With Decode-and-Forward Relays. IEEE Tran. Commun. VOL.55, NO.7, JULY 2007
[28]E. Van der Muelen, T.hree-terminal communication channels. Adv. Appl. Prob., vol.3, pp.120-154,1971.
[29]Thomas M. Cover, Abbas A. El Gamal. Capacity theorems for the Relay Channel. IEEE Trans. Inform. Theory, vol.25, pp.572-584,1979.
[30]T.M. Cover, A.A.E. Gamal.Capacity Theorems for the Relay Channel. IEEE Transactions on Information Theory, Sep.1979, vol.25, pp.572-584.
[31]A. Nosratinia, T. E. Hunter, and A. Hedayat.Cooperative communication in wireless networks. IEEE Commun. Mag., Oct.2004, vol.42, no.10, pp.74-80.
[32]Abbas El Gamal,Navid Hassanpour, and James Mammen.Relay Networks With Delays.IEEE Trans. Inf. Theory,October 2007, vol.53, no.10,pp.3413-3431.
[33]J.N. Laneman, D.N.C. Tse, G.W. Wonell.Cooperative diversity in wireless networks: efficient protocols and outage behavior.IEEE Transactions on Information Theory, 2004,50(12):3062-3080.
[34]Chirag S. Patel, Gordon L. Stuber and Thomas G. Pratt. Statistical Properties of Amplify and Forward Relay Fading Channels. IEEE Transactions on Information Theory,2006,55(1):1-9.
[35]Mazen O.Hasna and Mohamed-Slim Alouini.A Performance study of Dual-Hop Transmissions With Fixed Gain Relays.IEEE Tran. Commun. Vol.3. No.6, NOV.2004.
[36]I. Lee and D. Kim.BER analysis for decode-and-forward relaying in dissimilar Rayleigh fading channels. IEEE Commun. Lett., vol.11, pp.52-54, Jan.2007
[37]Sang Joon Kim, Natasha Devroye, Patrick Mitran, and Vahid Tarokh. Comparison of bi-directional relaying protocols. IEEE transactions on Information Theory,2008, pp.1-5.
[38]S.Lin and D.J.CostelloJr.Error control coding:fundamentals and applications, Englewood CliffS,NJ:Prentice — Hall,1984.
[39]S. Lin, D.J. Costello Jr., and M. J. Miller, Automatic Repeat request error-control schemes. IEEE Commun. Mag, vol.22,1984.pp.5-17
[40]F.Adachi, S.Ito and K.Ohno. Performance analysis of a time diversity ARQ in land mobile radio.IEEE Trans.Commun.Vol.37, No.2, Feb.1989, pp.177-183.
[41]B.A.Harvey,S.B.Wieker, Paeket combining systems based on the Viterbi decoder.IEEE Trans.Commun.Vol.42,No.2/3/4,1994,pp.1544-1557.
[42]S.Souissi, S.B.Wicker.A diversity combining DS/CDMA system with convolutional encoding and Viterbi decoding. IEEE Trans. Commun. Vol.44. No.2.May.1995, pp.304-312.
[43]Noh,K.-L.,Serpedin,E. and Suter,B.Optimum Cooperation of The Cooperative Coding Scheme for Frequency Division Half-Duplex relay channels.IEEE Trans. Commun.6(5).pp.1654-1658.2007.
[44]Simon,M.K.,and Alouini,M.-S.Digital Communication over Fading Channels:A Unified Approach to Performance Analysis.2000
[45]Gradshteyn,I.S..and Ryzhik,I.M..Table of Integrals,Series and Products(6th edn).New York:Academic Press.2000.
[46]Helmut Adam,Christian Bettstetter and Sidi Mohammed Senouci.Adaptive Relay Selection in Cooperative Wireless Networks. IEEE Trans. Commun.Sep.2008.
[47]M. A. Khojastepour, N. Ahmed, and B. Aazhang. Code design for the relay channel and factor graph decoding. in Proc. Asilomar Conference 2004, vol.2, pp.2000-2004.
[48]Furuzan Atay Onat and Abdulkareem Adinoyi.Optimum Threshold for SNR-based Selective Digital Relaying Schemes in Cooperative Wireless Networks. IEEE.Commun.Society.pp.970-975.June.2007.
[49]Aimal Khan, Volker K"uhn.On The Performance of Adptive Relaying with ARQ.2010 International ITG Workshop on Smart Antennas (WSA 2010).pp.121-127.2010.
[50]Meng Yu.Jing Li. Is amplify-and-forward practically better than decode-and-forward or vice versa?. Acoustics,Speech, and Signa Processing,2005. Proceedings. (ICASSP'05). IEEE International Conference on Volume 3,18-23 March 2005 pp:365-368
[51]Joachim Hagenauer. Rate-Compatible Punctured Convolutional Codes (RCPC Codes)and their Applications. IEEE Trans. Commun. Vol.36. No.4.Aprul.1988, pp.389-401.
[52]L.H.C.Lee. New Rate-Compatible Punctured Convolutional Codes for Viterbi Decoding. IEEE Tran.Commun.,VOL.42, NO.12, DEC.1994.pp.3073-3079.
[2]Teiatar I.E. Capacity of multi-antenna Gaussian channels. Bell Labs Technical Memorandum,1995. IEEE Trans. Commun., vol.56.pp.743-752.
[3]Foschini G. J. Layered space-time architecture for wireless communication in a Fading environment when using multi-element antennas. Bell Labs Technical, Journal, vol.1, no.2, pp.41-59,1996.
[4]E.Telatar. Capacity of muti-antenna Gaussian channels. European Transactions on Telecommunications,vol.10,no.6,pp.585-595,Nov./Dec.1999.
[5]A. Sendonaris, E. Erkip, and B. Aazhang. User cooperation diversity, Part I:System description. IEEE Trans. Commun., vol.51, no.11, pp.1927-1938, Nov.2003.
[6]A. Sendonaris, E. Erkip, and B. Aazhang. User cooperation diversity. Part II: implementation aspects and performance analysis. IEEE Trans. Commun., vol.51, no. 11, pp.1939-1948, Nov.2003.
[7]Theodore S.Rappaport.Wireless Communications Principles and Practice.Second Edition.2004.
[8]J.N. Laneman, D.N.C. Tse, G.W. Wornell. An Efficient Protocol for Realizing Cooperative Diversity in Wireless Networks. IEEE International Symposium on Information Theory, pp.294, June 2001.
[9]Isabella Cerutti, Andrea Fumagalli, and Puja Gupta.Cooperative ARQ Protocols in Slotted Radio Networks.Technical Report UTD,EE,2005,12.
[10]Zhao.B..Valente.M.C. Practical Relay Networks:A Generalization of Hybrid-ARQ. IEEE journal on selected Areas in Communications, pp.7-18,Jan,2005,
[11]M. Dianati, X. Ling, S. Naik, and X. Shen.A Node Cooperative ARQ Scheme for Wireless Ad-Hoc Networks.IFIP Networking 2005, May 2005, pp.1418-1421.
[12]李屹,纪红,马书惠.无线Ad hoc网络中协作重传机制的改进.北京邮电大学学报,2007,30(4)：23-27.
[13]Mehrdad Dianati, Xinhua Ling, Kshirasagar Naik, and Xuemin (Sherman) Shen.Performance Analysis of the Node Cooperative ARQ Scheme for Wireless Ad-Hoc Networks.IEEE Globecom 2005,pp.3063-3067.
[14]Lingfan Weng, Ross D. Murch.Achievable Diversity-Multiplexing-Delay Tradeoff for ARQ Cooperative Broadcast Channels.IEEE Trans. on Wireless Communications,2008, vol.7,no.5,pp1828-1832.
[15]余官定,张朝阳,仇佩亮.基于合作分集的新型自动重传协议,通信学报,2007,27(12)：20-25.
[16]Poramate Tarasak, Hlaing Minn,Yong Hoon Lee. Analysis of Incremental Relaying Protocol with RCPC in Cooperative Diversity Systems. IEEE Trans.2004,vol.36,pp.2537-2541.
[17]David Chase. Code Combining-A Maximum-Likelihood Decoding Approach for Combining an Arbitrary Number of Noisy Packets. IEEE Trans.vol.com-33, No.5, may 1985.pp.385-393.
[18]Lars K.Rasmussen and Stephen B. Wicker. A comparison of Two Combining Techniques for Equal Gain, Trellis Coded Diversity Receivers. IEEE Trans.vol.44, No.2, may 1995.pp.291-295.
[19]A Diversity Combining DS/CDMA System with Convolutional Encoding and Viterbi Decoding. IEEE Trans.vol.44, No.2, may 1995.
[20]陈庆春.基于码合并的混合差错控制及相关理论研究.西南交通大学,工学博士论文,2004年3月.
[21]Qingchun Chen, Pingzhi Fan.Performance Analysis of HARQ with Code Combining in packet-oriented CDMA system.Chinese Journal of Electronics.2004, No.1,pp:168-174.
[22]Qingchun Chen, Pingzhi Fan.Performance Evaluation of Hybrid-ARQ with Code Combining over Interleaved Rayleigh Fading Channel.IEEE Trans, on Vehicular Technology,2005,54(3):1207-1214.
[23]Qingqing Zhang and Saleem A.Kassam. Hybrid ARQ with Selective Combining for Fading Channels. IEEE Journal on selected areas in communications,Vol.17,No.5, MAY 1999
[24]Julian D. Morillo-Pozo, Jorge Garcia-Vidal. A Low Coordination Overhead C-ARQ Protocol with Frame Combining.IEEE PIMRC'07,2007, pp.1-5.
[25]Wenbo Xu,Jiaru Liu,Kai Niu and Lianhai Wu.Performance Analysis of Cooperative ARQ with Code combining over Nakagami-m Fading Channels.Wireless Pers Commun.June 2009.
[26]Inhye Park and Hyungkeun Lee,Taekon Kim. The Performance Analysis of Hybrid ARQ- Ⅱ for Cooperative Communication over Wireless Channels*. IEEE International Conference on Sensor Networks, Ubiquitous, and Trustworthy Computing.pp.402-408.June 2010.
[27]T. Wang, A. Cano and J. N. Laneman. High-Performance Cooperative Demodulation With Decode-and-Forward Relays. IEEE Tran. Commun. VOL.55, NO.7, JULY 2007
[28]E. Van der Muelen, T.hree-terminal communication channels. Adv. Appl. Prob., vol.3, pp.120-154,1971.
[29]Thomas M. Cover, Abbas A. El Gamal. Capacity theorems for the Relay Channel. IEEE Trans. Inform. Theory, vol.25, pp.572-584,1979.
[30]T.M. Cover, A.A.E. Gamal.Capacity Theorems for the Relay Channel. IEEE Transactions on Information Theory, Sep.1979, vol.25, pp.572-584.
[31]A. Nosratinia, T. E. Hunter, and A. Hedayat.Cooperative communication in wireless networks. IEEE Commun. Mag., Oct.2004, vol.42, no.10, pp.74-80.
[32]Abbas El Gamal,Navid Hassanpour, and James Mammen.Relay Networks With Delays.IEEE Trans. Inf. Theory,October 2007, vol.53, no.10,pp.3413-3431.
[33]J.N. Laneman, D.N.C. Tse, G.W. Wonell.Cooperative diversity in wireless networks: efficient protocols and outage behavior.IEEE Transactions on Information Theory, 2004,50(12):3062-3080.
[34]Chirag S. Patel, Gordon L. Stuber and Thomas G. Pratt. Statistical Properties of Amplify and Forward Relay Fading Channels. IEEE Transactions on Information Theory,2006,55(1):1-9.
[35]Mazen O.Hasna and Mohamed-Slim Alouini.A Performance study of Dual-Hop Transmissions With Fixed Gain Relays.IEEE Tran. Commun. Vol.3. No.6, NOV.2004.
[36]I. Lee and D. Kim.BER analysis for decode-and-forward relaying in dissimilar Rayleigh fading channels. IEEE Commun. Lett., vol.11, pp.52-54, Jan.2007
[37]Sang Joon Kim, Natasha Devroye, Patrick Mitran, and Vahid Tarokh. Comparison of bi-directional relaying protocols. IEEE transactions on Information Theory,2008, pp.1-5.
[38]S.Lin and D.J.CostelloJr.Error control coding:fundamentals and applications, Englewood CliffS,NJ:Prentice — Hall,1984.
[39]S. Lin, D.J. Costello Jr., and M. J. Miller, Automatic Repeat request error-control schemes. IEEE Commun. Mag, vol.22,1984.pp.5-17
[40]F.Adachi, S.Ito and K.Ohno. Performance analysis of a time diversity ARQ in land mobile radio.IEEE Trans.Commun.Vol.37, No.2, Feb.1989, pp.177-183.
[41]B.A.Harvey,S.B.Wieker, Paeket combining systems based on the Viterbi decoder.IEEE Trans.Commun.Vol.42,No.2/3/4,1994,pp.1544-1557.
[42]S.Souissi, S.B.Wicker.A diversity combining DS/CDMA system with convolutional encoding and Viterbi decoding. IEEE Trans. Commun. Vol.44. No.2.May.1995, pp.304-312.
[43]Noh,K.-L.,Serpedin,E. and Suter,B.Optimum Cooperation of The Cooperative Coding Scheme for Frequency Division Half-Duplex relay channels.IEEE Trans. Commun.6(5).pp.1654-1658.2007.
[44]Simon,M.K.,and Alouini,M.-S.Digital Communication over Fading Channels:A Unified Approach to Performance Analysis.2000
[45]Gradshteyn,I.S..and Ryzhik,I.M..Table of Integrals,Series and Products(6th edn).New York:Academic Press.2000.
[46]Helmut Adam,Christian Bettstetter and Sidi Mohammed Senouci.Adaptive Relay Selection in Cooperative Wireless Networks. IEEE Trans. Commun.Sep.2008.
[47]M. A. Khojastepour, N. Ahmed, and B. Aazhang. Code design for the relay channel and factor graph decoding. in Proc. Asilomar Conference 2004, vol.2, pp.2000-2004.
[48]Furuzan Atay Onat and Abdulkareem Adinoyi.Optimum Threshold for SNR-based Selective Digital Relaying Schemes in Cooperative Wireless Networks. IEEE.Commun.Society.pp.970-975.June.2007.
[49]Aimal Khan, Volker K"uhn.On The Performance of Adptive Relaying with ARQ.2010 International ITG Workshop on Smart Antennas (WSA 2010).pp.121-127.2010.
[50]Meng Yu.Jing Li. Is amplify-and-forward practically better than decode-and-forward or vice versa?. Acoustics,Speech, and Signa Processing,2005. Proceedings. (ICASSP'05). IEEE International Conference on Volume 3,18-23 March 2005 pp:365-368
[51]Joachim Hagenauer. Rate-Compatible Punctured Convolutional Codes (RCPC Codes)and their Applications. IEEE Trans. Commun. Vol.36. No.4.Aprul.1988, pp.389-401.
[52]L.H.C.Lee. New Rate-Compatible Punctured Convolutional Codes for Viterbi Decoding. IEEE Tran.Commun.,VOL.42, NO.12, DEC.1994.pp.3073-3079.