多载波CDMA频偏估计与多址干扰联合检测
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摘要
CDMA技术以其高抗干扰能力、高容量、高保密性等技术优势在第三代移动通信系统中被广泛应用，然而在高速数据业务中，严重的码间干扰和符号间干扰会导致系统性能明显下降。正交频分复用(OFDM)技术作为一种多载波传输的技术，在处理高速数据的系统中是非常有效的，该技术将系统带宽分成若干正交的子载波，每个子载波只传输相对低速率的数据。
CDMA技术和OFDM技术结合产生了多载波CDMA系统，它很好地解决了高速数据业务下传统CDMA系统性能下降等一系列问题。然而多载波CDMA系统也存在一些问题，多址干扰和频率偏移等问题会带来明显的性能下降。本文的研究是针对多载波CDMA系统的多址干扰和频率偏移两个问题进行的，希望通过我们的研究，能够进一步明确多载波CDMA系统内的干扰类型及其来源，综合考虑多载波CDMA系统中主要的干扰和性能下降因素，找到一种将频率偏移与多址干扰联合起来进行考虑和消除的方法，提高多载波CDMA系统的性能和抗干扰能力，并进而提高系统的容量。
论文的研究结合了中德(西门子)国际合作项目《面向后3G蜂窝移动通信的OFCDMA方案研究》及安徽省自然基金项目《CDMA自适应盲多用户检测方法的研究》(03042208)。
论文从移动通信的历史和发展出发，首先回顾了第一代、第二代通信系统的技术特点和发展历程，介绍了第三代通信系统的分类和发展态势，展望了超3G系统的研究领域和研究热点。然后对超3G系统研究的一个重要领域——多载波CDMA系统的类型和主要技术进行了介绍和分析，进而对多载波CDMA系统中的多址干扰和频率偏移进行了较为深入的分析，衡量了频率偏移对多载波CDMA系统性能的影响。随后，利用理论分析和实验仿真的方法比较了一些常规多用户检测器应用于存在频率偏移的多载波CDMA系统时的不同性能，指出了多址干扰和频率偏移对多载波CDMA系统性能的影响。最后，在各种分析结果和理论的基础上，我们提出了一种将基于保护间隔的最大似然频偏估计方法和改进的并行多址干扰消除方法联合起来进行处理的ML-MPIC方法，在一定程度上改善了频偏多载波CDMA系统的性能，计算
安徽大学硕士论文
机仿真的结果进一步验证了MLMPIC方法的有效性。
For wireless communications, direct sequence code division multiple access (DS-CDMA) techniques have received a great deal of attention due to the expectation of capacity increase, interference rejection capability, security, and so on. In a high data rate application such as multimedia services, however, the capacity of DS-CDMA systems is limited by both the inter-chip, or inter-symbol interference. A demand for very high bit rates brought OFDM systems into focus. Orthogonal Frequency Division Multiplexing (OFDM) is a multicarrier transmission technique, which divides the available spectrum into many carriers, each one being modulated by a low rate data stream.
MC-CDMA system is a combination of direct-sequence CDMA and multicarrier modulation systems. Much attention has been paid to it, because the system can achieve better performance than conventional CDMA in high data applications and it is potentially robust to channel frequency selectivity. But MC-CDMA system still has some problems. Some of the most important sources for performance degradation of MC-CDMA systems are carrier frequency offset and the multiple access interference (MAI). In OFDM systems similar to MC-CDMA systems, many schemes have been proposed to estimate the frequency offset. These schemes, however, cannot be directly applied to MC-CDMA systems due to the MAI and the full correlation between the different subcarrier data. In DS-CDMA systems, many detection schemes have been proposed to eliminate the MAI. However, using these schemes for MC-CDMA systems, their performances get considerably worse even in the presence of the small frequency offset. Therefore, the frequency offset and the MAI sh
ould be jointly considered. Our research is focused on these two problems in MC-CDMA system. We hope to clarify the types and originations of interference and consider the main interference synthetically in MC-CDMA system. Our target is to find out a solution to estimate the frequency and eliminate the MAI jointly and also by this solution we can improve the performance and capacity in MC-CDMA system.
The work in this thesis is part of the International Cooperate Project "Research on OFCDMA for beyond 3G mobile communications" and Nature Science Research Project of Anhui Education Department, "Research on the blind adaptive multiuser detection in CDMA systems".
In this thesis we firstly analyze the MAI and frequency offset in multicarrier CDMA system respectively. Then we evaluate the effect of frequency offset in multicarrier CDMA systems by computer simulation and theoretical analysis. The performance analysis of some conventional multiuser detectors in multicarrier CDMA with frequency offset is performed. Based on the analysis of frequency offset and multiuser detectors in multicarrier
CDMA system, we propose a method, named ML-MPIC method, to estimate the frequency offset for the desired user and to eliminate the MAI jointly .The performance analysis of the scheme is given, simulation results with different user number show its better performance than that of systems which deal with these two problems separately.
CDMA技术和OFDM技术结合产生了多载波CDMA系统，它很好地解决了高速数据业务下传统CDMA系统性能下降等一系列问题。然而多载波CDMA系统也存在一些问题，多址干扰和频率偏移等问题会带来明显的性能下降。本文的研究是针对多载波CDMA系统的多址干扰和频率偏移两个问题进行的，希望通过我们的研究，能够进一步明确多载波CDMA系统内的干扰类型及其来源，综合考虑多载波CDMA系统中主要的干扰和性能下降因素，找到一种将频率偏移与多址干扰联合起来进行考虑和消除的方法，提高多载波CDMA系统的性能和抗干扰能力，并进而提高系统的容量。
论文的研究结合了中德(西门子)国际合作项目《面向后3G蜂窝移动通信的OFCDMA方案研究》及安徽省自然基金项目《CDMA自适应盲多用户检测方法的研究》(03042208)。
论文从移动通信的历史和发展出发，首先回顾了第一代、第二代通信系统的技术特点和发展历程，介绍了第三代通信系统的分类和发展态势，展望了超3G系统的研究领域和研究热点。然后对超3G系统研究的一个重要领域——多载波CDMA系统的类型和主要技术进行了介绍和分析，进而对多载波CDMA系统中的多址干扰和频率偏移进行了较为深入的分析，衡量了频率偏移对多载波CDMA系统性能的影响。随后，利用理论分析和实验仿真的方法比较了一些常规多用户检测器应用于存在频率偏移的多载波CDMA系统时的不同性能，指出了多址干扰和频率偏移对多载波CDMA系统性能的影响。最后，在各种分析结果和理论的基础上，我们提出了一种将基于保护间隔的最大似然频偏估计方法和改进的并行多址干扰消除方法联合起来进行处理的ML-MPIC方法，在一定程度上改善了频偏多载波CDMA系统的性能，计算
安徽大学硕士论文
机仿真的结果进一步验证了MLMPIC方法的有效性。
For wireless communications, direct sequence code division multiple access (DS-CDMA) techniques have received a great deal of attention due to the expectation of capacity increase, interference rejection capability, security, and so on. In a high data rate application such as multimedia services, however, the capacity of DS-CDMA systems is limited by both the inter-chip, or inter-symbol interference. A demand for very high bit rates brought OFDM systems into focus. Orthogonal Frequency Division Multiplexing (OFDM) is a multicarrier transmission technique, which divides the available spectrum into many carriers, each one being modulated by a low rate data stream.
MC-CDMA system is a combination of direct-sequence CDMA and multicarrier modulation systems. Much attention has been paid to it, because the system can achieve better performance than conventional CDMA in high data applications and it is potentially robust to channel frequency selectivity. But MC-CDMA system still has some problems. Some of the most important sources for performance degradation of MC-CDMA systems are carrier frequency offset and the multiple access interference (MAI). In OFDM systems similar to MC-CDMA systems, many schemes have been proposed to estimate the frequency offset. These schemes, however, cannot be directly applied to MC-CDMA systems due to the MAI and the full correlation between the different subcarrier data. In DS-CDMA systems, many detection schemes have been proposed to eliminate the MAI. However, using these schemes for MC-CDMA systems, their performances get considerably worse even in the presence of the small frequency offset. Therefore, the frequency offset and the MAI sh
ould be jointly considered. Our research is focused on these two problems in MC-CDMA system. We hope to clarify the types and originations of interference and consider the main interference synthetically in MC-CDMA system. Our target is to find out a solution to estimate the frequency and eliminate the MAI jointly and also by this solution we can improve the performance and capacity in MC-CDMA system.
The work in this thesis is part of the International Cooperate Project "Research on OFCDMA for beyond 3G mobile communications" and Nature Science Research Project of Anhui Education Department, "Research on the blind adaptive multiuser detection in CDMA systems".
In this thesis we firstly analyze the MAI and frequency offset in multicarrier CDMA system respectively. Then we evaluate the effect of frequency offset in multicarrier CDMA systems by computer simulation and theoretical analysis. The performance analysis of some conventional multiuser detectors in multicarrier CDMA with frequency offset is performed. Based on the analysis of frequency offset and multiuser detectors in multicarrier
CDMA system, we propose a method, named ML-MPIC method, to estimate the frequency offset for the desired user and to eliminate the MAI jointly .The performance analysis of the scheme is given, simulation results with different user number show its better performance than that of systems which deal with these two problems separately.
引文
[1] Yee, N.; Linnartz, J.-P. ;"Wiener filtering of multi-carrier CDMA in Rayleigh fading channel"; Personal, Indoor and Mobile Radio Communications, 1994. Wireless Networks-Catching the Mobile Future.5th IEEE International Symposium on, Volume: 4, 18-23 Sept. 1994 Page(s): 1344 -1347 vol.4
[2] Yee, N.; Linnartz, J.-P. ;"BER of multi-carrier CDMA in an indoor Rician fading channel"; Signals, Systems and Computers, 1993. 1993 Conference Record of The Twenty-Seventh Asilomar Conference on, 1-3 Nov. 1993 Page(s): 426-430 vol.1
[3] Yee, N.; Linnartz, J.-P. ;"Controlled equalization of multi-carrier CDMA in an indoor Rician fading channel"; Vehicular Technology Conference,1994 IEEE 44th, 8-10 June 1994 Page(s): 1665-1669 vol.3
[4] Linnartz, J.-P.M.G;. "Performance analysis of synchronous MC-CDMA in mobile Rayleigh channel with both delay and Doppler spreads"; Vehicular Technology, IEEE Transactions on, Volume: 50 Issue: 6, Nov.2001 Page(s): 1375-1387
[5] Hara, S.; Prasad, R.; "Design and performance of multicarrier CDMA system in frequency-selective Rayleigh fading channels"; Vehicular Technology, IEEE Transactions on, Volume: 48 Issue: 5, Sept. 1999 Page(s): 1584-1595
[6] Xiang Gui; Tung Sang Ng; "Performance of asynchronous orthogonal multicarrier CDMA system in frequency selective fading channel"; Communications, IEEE Transactions on, Volume: 47 Issue: 7, July 1999 Page(s): 1084-1091
[7] Younsun Kim; Keukjoon Bang; Sooyong Choi; Cheoiwoo You; Daesik Hong; "Effect of carrier frequency offset on performance of MC-CDMA
systems"; Electronics Letters, Volume: 35 Issue: 5,4 March 1999 Page(s):378-379
[8] Jiho Jang; Kwang Bok Lee; "Effects of frequency offset on MC/CDMA system performance"; Vehicular Technology Conference, 1999 IEEE 49th, Volume: 1,16-20 May 1999 Page(s): 566-570 vol.1
[9] Prasad, R.; Hara, S.; "An overview of multi-carrier CDMA" Spread Spectrum Techniques and Applications Proceedings, 1996., IEEE 4th International Symposium on, Volume: 1,22-25 Sept. 1996 Page(s): 107-114 vol.1
[10] Kivanc, D.; Hui Liu; "Uplink performance of MC-CDMA in the presence of frequency offset"; Vehicular Technology Conference, 1999. VTC 1999-Fall. IEEE VTS 50th, Volume: 5, 19-22 Sept. 1999 Page(s): 2855-2859 vol.5
[11] Visser, M.A.; Bar-Ness, Y.; "Joint multiuser detection and frequency offset correction for downlink MC-CDMA"; Global Telecommunications Conference, 1999. GLOBECOM '99, Volume: 5, 1999 Page(s): 2400-2404 vol.5
[12] A. Chouly, A. Brajal, and S. Jourdan; "Orthogonal multicarrier techniques applied to direct sequence spread spectrum CDMA systems";in Proc. IEEE GLOBECOM'93, Nov. 1993, pp. 1723-1728.
[13] Douglas N. Rowitch; Laurence B. Milstein; "Convolutionally Coded Multicarrier DS-CDMA Systems in a Multipath Fading Channel"; IEEE TRANSACTIONS ON COMMUNICATIONS, VOL. 47, NO.10,OCTOBER 1999 pp1570-1582
[14] Vandendorpe, L.; "Multitone spread spectrum multiple access communications system in a multipath Rician fading channel";Communications, 1994. ICC 94, SUPERCOMM/ICC'94, Conference Record, Serving Humanity Through Communications. IEEE International Conference on, 1-5 May 1994 Page(s): 1638-1642 vol.3
[15] Kondo, S.; Milstein, L; "On the use of multicarrier direct sequence spread spectrum systems"; Military Communications Conference, 1993.MILCOM '93. Conference record. 'Communications on the Move', IEEE,Volume: 1,11-14 Oct. 1993 Page(s): 52 -56 vol.1
[16] Kondo, S.; Milstein, L.B; "Multicarrier CDMA system with co-channel interference cancellation"; Vehicular Technology Conference, 1994 IEEE 44th, 8-10 June 1994 Page(s): 1640 -1644 vol.3
[17] Kondo, S.; Milstein, L.B;"Multicarrier DS CDMA systems in the presence of partial band interference"; Military Communications Conference, 1994. MILCOM '94. Conference Record, 1994 IEEE , 2-5 Oct. 1994Page(s): 588-592 vol.2
[18] Kondo, S.; Miistein, L.B.; "On the Performance of Multicarrier DS CDMA Systems"; Communications, IEEE Transactions on, Volume: 43 Issue: 12, Dec. 1995 Page(s): 3101
[19] Kondo, S.; Milstein, B;."Performance of multicarrier DS CDMA systems";Communications, IEEE Transactions on, Volume: 44 Issue: 2, Feb. 1996 Page(s): 238-246
[20] Bang won Seo; Hyung-Myung Kim; "Frequency offset estimation and multiuser detection for MC-CDMA systems"; MILCOM 2002.Proceedings, Volume: 2, Oct. 7-10, 2002 Page(s): 804-807
[21] Aigang Feng; Qinye Yin; Jianguo Zhang; Ke Deng; "Blind channel estimation in synchronous MC-CDMA system with consideration of carrier offset compensation"; Vehicular Technology Conference, 2002.VTC Spring 2002. IEEE 55th, Volume: 2, 6-9 May 2002 Page(s): 660-664 vol.2
[22] Gui, X.; Ng, T.S.; "Asynchronous orthogonal multi-carrier CDMA using equal gain combining in multipath Rayleigh fading channel";Communication Technology Proceedings, 1998. ICCT'98. 1998 International Conference on, Volume: vol.2 , 22-24 Oct. 1998 Page(s): 4
pp. vol.2
[23] Gui, X.; Ng, T.S.; "Performance comparison of asynchronous orthogonal multi-carrier CDMA in frequency selective channel"; Spread Spectrum Techniques and Applications,1998. Proceedings, 1998 IEEE 5th International Symposium on, Volume: 2,2-4 Sept. 1998 Page(s): 494-497 vol.2
[24] Shi, Q.; Latva-aho, M.; "Performance analysis of MC-CDMA in Rayleigh fading channels with correlated envelopes and phases"; Communications,IEE Proceedings-, Volume: 150 Issue: 3, June 2003 Page(s): 214-220
[25] Popovic, B.M.; "Spreading sequences for multi-carrier CDMA systems";CDMA Techniques and Applications for Third Generation Mobile Systems (Digest No: 1997/129), IEE Colloquium on, 19 May 1997 Page(s):8/1-8/6
[26] Xiaojun Wu; Qinye Yin; Hanguo Zhang; Ke Deng; "Time-domain multiuser detection for MC-CDMA systems without cyclic prefix";Communications, 2002. ICC 2002. IEEE International Conference on,Volume: 2,28 April-2 May 2002 Page(s): 921 -925 vol.2
[27] Slimane, S.B; "MC-CDMA with quadrature spreading over frequency selective fading channels"; Global Telecommunications Conference, 1997. GLOBECOM '97, IEEE, Volume: 1, 3-8 Nov. 1997 Page(s): 315-319 vol.1
[28] Younsun Kim; Sooyong Choi; Chulwoo You; Daesik Hong; "Effect of carrier frequency offset on the performance of an MC-CDMA system and its countermeasure using pulse shaping"; Communications, 1999. ICC '99.1999 IEEE International Conference on, Volume: 1, 6-10 June 1999 Page(s): 167-171 vol.1
[29] Kalofonos, D.N.; Stojanovic, M.; Proakis, J.G.; "On the performance of adaptive MMSE detectors for a MC-CDMA system in fast fading Rayleigh channels"; Personal, Indoor and Mobile Radio Communications,1998. The Ninth IEEE International Symposium on, Volume: 3,8-11 Sept.
1998 Page(s): 1309-1313 vol.3
[30] Junhyun Park; Jooeung Kim; Sooyong Choi; Namsin Cho; Daesik Hong;"Performance of MC-CDMA systems in non-independent Rayleigh fading"; Communications, 1999. ICC '99. 1999 IEEE International Conference on, Volume: 1,6-10 June 1999 Page(s): 506 -510 vol.1
[31] Tomba, L.; Krzymien, W.A.; "Sensitivity of the MC-CDMA access scheme to carrier phase noise and frequency offset "; Vehicular Technology, IEEE Transactions on, Volume: 48 Issue: 5, Sept. 1999 Page(s): 1657-1665
[32] 佟学俭，罗淘；《OFDM移动通信技术原理与应用》人民邮电出版社 2003．6
[2] Yee, N.; Linnartz, J.-P. ;"BER of multi-carrier CDMA in an indoor Rician fading channel"; Signals, Systems and Computers, 1993. 1993 Conference Record of The Twenty-Seventh Asilomar Conference on, 1-3 Nov. 1993 Page(s): 426-430 vol.1
[3] Yee, N.; Linnartz, J.-P. ;"Controlled equalization of multi-carrier CDMA in an indoor Rician fading channel"; Vehicular Technology Conference,1994 IEEE 44th, 8-10 June 1994 Page(s): 1665-1669 vol.3
[4] Linnartz, J.-P.M.G;. "Performance analysis of synchronous MC-CDMA in mobile Rayleigh channel with both delay and Doppler spreads"; Vehicular Technology, IEEE Transactions on, Volume: 50 Issue: 6, Nov.2001 Page(s): 1375-1387
[5] Hara, S.; Prasad, R.; "Design and performance of multicarrier CDMA system in frequency-selective Rayleigh fading channels"; Vehicular Technology, IEEE Transactions on, Volume: 48 Issue: 5, Sept. 1999 Page(s): 1584-1595
[6] Xiang Gui; Tung Sang Ng; "Performance of asynchronous orthogonal multicarrier CDMA system in frequency selective fading channel"; Communications, IEEE Transactions on, Volume: 47 Issue: 7, July 1999 Page(s): 1084-1091
[7] Younsun Kim; Keukjoon Bang; Sooyong Choi; Cheoiwoo You; Daesik Hong; "Effect of carrier frequency offset on performance of MC-CDMA
systems"; Electronics Letters, Volume: 35 Issue: 5,4 March 1999 Page(s):378-379
[8] Jiho Jang; Kwang Bok Lee; "Effects of frequency offset on MC/CDMA system performance"; Vehicular Technology Conference, 1999 IEEE 49th, Volume: 1,16-20 May 1999 Page(s): 566-570 vol.1
[9] Prasad, R.; Hara, S.; "An overview of multi-carrier CDMA" Spread Spectrum Techniques and Applications Proceedings, 1996., IEEE 4th International Symposium on, Volume: 1,22-25 Sept. 1996 Page(s): 107-114 vol.1
[10] Kivanc, D.; Hui Liu; "Uplink performance of MC-CDMA in the presence of frequency offset"; Vehicular Technology Conference, 1999. VTC 1999-Fall. IEEE VTS 50th, Volume: 5, 19-22 Sept. 1999 Page(s): 2855-2859 vol.5
[11] Visser, M.A.; Bar-Ness, Y.; "Joint multiuser detection and frequency offset correction for downlink MC-CDMA"; Global Telecommunications Conference, 1999. GLOBECOM '99, Volume: 5, 1999 Page(s): 2400-2404 vol.5
[12] A. Chouly, A. Brajal, and S. Jourdan; "Orthogonal multicarrier techniques applied to direct sequence spread spectrum CDMA systems";in Proc. IEEE GLOBECOM'93, Nov. 1993, pp. 1723-1728.
[13] Douglas N. Rowitch; Laurence B. Milstein; "Convolutionally Coded Multicarrier DS-CDMA Systems in a Multipath Fading Channel"; IEEE TRANSACTIONS ON COMMUNICATIONS, VOL. 47, NO.10,OCTOBER 1999 pp1570-1582
[14] Vandendorpe, L.; "Multitone spread spectrum multiple access communications system in a multipath Rician fading channel";Communications, 1994. ICC 94, SUPERCOMM/ICC'94, Conference Record, Serving Humanity Through Communications. IEEE International Conference on, 1-5 May 1994 Page(s): 1638-1642 vol.3
[15] Kondo, S.; Milstein, L; "On the use of multicarrier direct sequence spread spectrum systems"; Military Communications Conference, 1993.MILCOM '93. Conference record. 'Communications on the Move', IEEE,Volume: 1,11-14 Oct. 1993 Page(s): 52 -56 vol.1
[16] Kondo, S.; Milstein, L.B; "Multicarrier CDMA system with co-channel interference cancellation"; Vehicular Technology Conference, 1994 IEEE 44th, 8-10 June 1994 Page(s): 1640 -1644 vol.3
[17] Kondo, S.; Milstein, L.B;"Multicarrier DS CDMA systems in the presence of partial band interference"; Military Communications Conference, 1994. MILCOM '94. Conference Record, 1994 IEEE , 2-5 Oct. 1994Page(s): 588-592 vol.2
[18] Kondo, S.; Miistein, L.B.; "On the Performance of Multicarrier DS CDMA Systems"; Communications, IEEE Transactions on, Volume: 43 Issue: 12, Dec. 1995 Page(s): 3101
[19] Kondo, S.; Milstein, B;."Performance of multicarrier DS CDMA systems";Communications, IEEE Transactions on, Volume: 44 Issue: 2, Feb. 1996 Page(s): 238-246
[20] Bang won Seo; Hyung-Myung Kim; "Frequency offset estimation and multiuser detection for MC-CDMA systems"; MILCOM 2002.Proceedings, Volume: 2, Oct. 7-10, 2002 Page(s): 804-807
[21] Aigang Feng; Qinye Yin; Jianguo Zhang; Ke Deng; "Blind channel estimation in synchronous MC-CDMA system with consideration of carrier offset compensation"; Vehicular Technology Conference, 2002.VTC Spring 2002. IEEE 55th, Volume: 2, 6-9 May 2002 Page(s): 660-664 vol.2
[22] Gui, X.; Ng, T.S.; "Asynchronous orthogonal multi-carrier CDMA using equal gain combining in multipath Rayleigh fading channel";Communication Technology Proceedings, 1998. ICCT'98. 1998 International Conference on, Volume: vol.2 , 22-24 Oct. 1998 Page(s): 4
pp. vol.2
[23] Gui, X.; Ng, T.S.; "Performance comparison of asynchronous orthogonal multi-carrier CDMA in frequency selective channel"; Spread Spectrum Techniques and Applications,1998. Proceedings, 1998 IEEE 5th International Symposium on, Volume: 2,2-4 Sept. 1998 Page(s): 494-497 vol.2
[24] Shi, Q.; Latva-aho, M.; "Performance analysis of MC-CDMA in Rayleigh fading channels with correlated envelopes and phases"; Communications,IEE Proceedings-, Volume: 150 Issue: 3, June 2003 Page(s): 214-220
[25] Popovic, B.M.; "Spreading sequences for multi-carrier CDMA systems";CDMA Techniques and Applications for Third Generation Mobile Systems (Digest No: 1997/129), IEE Colloquium on, 19 May 1997 Page(s):8/1-8/6
[26] Xiaojun Wu; Qinye Yin; Hanguo Zhang; Ke Deng; "Time-domain multiuser detection for MC-CDMA systems without cyclic prefix";Communications, 2002. ICC 2002. IEEE International Conference on,Volume: 2,28 April-2 May 2002 Page(s): 921 -925 vol.2
[27] Slimane, S.B; "MC-CDMA with quadrature spreading over frequency selective fading channels"; Global Telecommunications Conference, 1997. GLOBECOM '97, IEEE, Volume: 1, 3-8 Nov. 1997 Page(s): 315-319 vol.1
[28] Younsun Kim; Sooyong Choi; Chulwoo You; Daesik Hong; "Effect of carrier frequency offset on the performance of an MC-CDMA system and its countermeasure using pulse shaping"; Communications, 1999. ICC '99.1999 IEEE International Conference on, Volume: 1, 6-10 June 1999 Page(s): 167-171 vol.1
[29] Kalofonos, D.N.; Stojanovic, M.; Proakis, J.G.; "On the performance of adaptive MMSE detectors for a MC-CDMA system in fast fading Rayleigh channels"; Personal, Indoor and Mobile Radio Communications,1998. The Ninth IEEE International Symposium on, Volume: 3,8-11 Sept.
1998 Page(s): 1309-1313 vol.3
[30] Junhyun Park; Jooeung Kim; Sooyong Choi; Namsin Cho; Daesik Hong;"Performance of MC-CDMA systems in non-independent Rayleigh fading"; Communications, 1999. ICC '99. 1999 IEEE International Conference on, Volume: 1,6-10 June 1999 Page(s): 506 -510 vol.1
[31] Tomba, L.; Krzymien, W.A.; "Sensitivity of the MC-CDMA access scheme to carrier phase noise and frequency offset "; Vehicular Technology, IEEE Transactions on, Volume: 48 Issue: 5, Sept. 1999 Page(s): 1657-1665
[32] 佟学俭，罗淘；《OFDM移动通信技术原理与应用》人民邮电出版社 2003．6