短波数据传输中的Turbo均衡技术研究
摘要
在短波通信系统中,多径时延会使信号产生符号间干扰(ISI),影响了数据传输的质量。Turbo均衡技术利用Turbo原理将信道均衡与译码结合起来,通过不断的迭代来消除ISI。
首先介绍了几种比较经典的均衡器,以及一些常用的均衡算法。然后重点研究了Turbo均衡的基本原理,详细介绍了几种常见的Turbo均衡算法,并对均衡中输出的软信息进行了计算量的简化。基于常见算法在复杂度和性能方面的优缺点,重点对基于MMSE的近似算法、软干扰抵消(SIC)的改进算法以及两者的混合算法进行了研究,并对这些算法在典型信道下的性能进行了仿真。仿真表明,这些算法不但拥有线性的复杂度,而且经过几次迭代以后可以获得与线性MMSE均衡算法几乎相近的性能。
最后,将Turbo均衡技术应用到实际的短波通信系统中,结合短波通信广泛应用的非线性数据检测算法(NDDE)得到了一种NDDE/SIC均衡算法,在短波信道模拟器上的测试表明该算法具有很好的性能。
The serious inter-symbol interference (ISI) caused by multipath will degrade the performance of the HF communication system. Turbo equalization joints equalization and decoding to cancel ISI through an iterative approach.
Firstly, some classical equalizers and its equalization algorithms are introduced. Then the principle of Turbo equalization is investigated and some Turbo equalization algorithms are studied to simplify its complexity of calculating the soft information. Considering the performance of these algorithms as well as their complexity, the approximate algorithms based on the minimum mean square error (MMSE) criterion、some modified algorithms of the conventional soft interference canceller (SIC) and the hybrid algorithm of MMSE and SIC are introduced and simulated in a typical ISI channel. The simulation and analytical results show that these algorithms exhibit similar performances as compared to the linear MMSE algorithm while providing the very low linear computational complexity.
Finally, Turbo equalization is applied to the HF communication system. Combined with the nonlinear data detection algorithm (NDDE) widely used in HF communication, we obtain a NDDE/SIC algorithm. The results coming from the HF channel simulator show that the algorithm has a good performance.
首先介绍了几种比较经典的均衡器,以及一些常用的均衡算法。然后重点研究了Turbo均衡的基本原理,详细介绍了几种常见的Turbo均衡算法,并对均衡中输出的软信息进行了计算量的简化。基于常见算法在复杂度和性能方面的优缺点,重点对基于MMSE的近似算法、软干扰抵消(SIC)的改进算法以及两者的混合算法进行了研究,并对这些算法在典型信道下的性能进行了仿真。仿真表明,这些算法不但拥有线性的复杂度,而且经过几次迭代以后可以获得与线性MMSE均衡算法几乎相近的性能。
最后,将Turbo均衡技术应用到实际的短波通信系统中,结合短波通信广泛应用的非线性数据检测算法(NDDE)得到了一种NDDE/SIC均衡算法,在短波信道模拟器上的测试表明该算法具有很好的性能。
The serious inter-symbol interference (ISI) caused by multipath will degrade the performance of the HF communication system. Turbo equalization joints equalization and decoding to cancel ISI through an iterative approach.
Firstly, some classical equalizers and its equalization algorithms are introduced. Then the principle of Turbo equalization is investigated and some Turbo equalization algorithms are studied to simplify its complexity of calculating the soft information. Considering the performance of these algorithms as well as their complexity, the approximate algorithms based on the minimum mean square error (MMSE) criterion、some modified algorithms of the conventional soft interference canceller (SIC) and the hybrid algorithm of MMSE and SIC are introduced and simulated in a typical ISI channel. The simulation and analytical results show that these algorithms exhibit similar performances as compared to the linear MMSE algorithm while providing the very low linear computational complexity.
Finally, Turbo equalization is applied to the HF communication system. Combined with the nonlinear data detection algorithm (NDDE) widely used in HF communication, we obtain a NDDE/SIC algorithm. The results coming from the HF channel simulator show that the algorithm has a good performance.
引文
[1]沈琪琪,朱德生.短波通信.西安电子科技大学出版社.1989.
[2]郭梯云,邬国杨,李建东.移动通信.西安电子科技大学.2005.
[3]Lucky.R.W.,Automatic equalization for digital communication,Bell Syst.Tech.J.,vol 44, pp.547-588,April 1965.
[4] J.G. Proakis, J. H. Miller. An Adaptive Receive for Digital Signaling through Channels with Intersymbol interference. IEEE Trans. Inf Theory, 1969, 15(3):484~97.
[5] Ungerboeck .G ,Theory on the Speed of Convergence in Adaptive Equalizers for Digital Communication. IBM J.Res.Dev, 1972,16(11):546~555.
[6]D.Godard. Channel Equalization Using a Kalman filter for Fast Data Transmission. IBM J. Research and Development,l974 21(5):267~273.
[7]D.D. Falconer,L.Ljung. Application of Fast Kalman Estimation to Adaptive Equalization . IEEE Trans.Commu, 1978 , 26(10): 1439~1446.
[8]戴懿,曾加,郑志航.Turbo码新译码算法.上海交通大学学报,1998,32(6):33~37
[9] Ralf Koetter, Andrew.C.Singer. Turbo Equalization .IEEE,Signal Processing Magazine, 2004:67~81.
[10] M. Tüchler, A. Singer, and R. Koetter, Minimum mean square error equalization using a priori information,IEEE Trans. Signal Processing, 2002, 50(3):673~683.
[11]H. Poor, An Introduction to Signal, Detection and Estimation, 2nded.New York: Springer-Verlag, 1994.
[12]Krishna R.Narayanan,Xiaodong Wang,Guosen Yue. Estimation the PDF of the SIC_MMSE Equalizer Output and Its Applications in Designing LDPC Codes With Turbo Equalization, IEEE Trans.Commun,vol.4,No.1,January 2005.
[13] M. Tuchler, R. Koetter, A. Singer. Turbo equalization: principles and new results.IEEE Trans on Comm, 2002,20(5): 754~767.
[14]Adebisi B,Giovaneli C L,Honary B. Low Complexity Turbo Equalization for Power Line Communications. IEEE Trans.Commun., 2006,50(4):553-559.
[15]郭淑霞,韩棕等.基于无线信道的软干扰抵消Turbo均衡技术研究[J].计算机测量与控制,2009.17(7).
[16] F. Vogelbruch and S. Haar, Low complexity turbo equalization based on soft feedback interference cancellation, IEEE Commun. Lett., vol. 9,pp. 586-588, Jul. 2005.
[17] D. Ampeliotis and K. Berberidis, A new turbo equalizer with linear complexity, in 13th European Signal Processing Conference (EUSIPCO 2005), Antalya,Turkey,September 2005.
[18] K. Berberidis, A. Marava, P. Karaivazoglou and J. Palicot, Robust and Fast Converging Decision Feedback Equalizer Based on a New Adaptive Semi-Blind Channel Estimation Algorithm, in Proc. of the 2001 IEEE GLOBECOM, San Antonio, USA, Nov. 2001.
[19] A.Glavieux,C.Laot,and J. Labat, Turbo equalization over a frequency selective channel, in Proc. Int. Symposium on Turbo codes & relared topics, Brest, France, Sept. 1997,pp.96-102.
[20]徐俊,蒋志红.Turbo均衡的多种算法及其性能比较[J].重庆邮电学院学报,2003,15(1):15-19.
[21]方毅伟.短波通信中Turbo均衡技术的研究.武汉:华中科技大学.2004.
[22]Renato R.Lopes and John R.Barry. The Soft-Feedback Equalizer for Turbo Equalization of Highly Dispersive Channels, IEEE Trans.Commun,vol.54,No.5,May 2006.
[23]杨静国,周新力等.短波信道数字通信中Turbo均衡技术研究.舰船电子工程.Vol.28,No
[24] C.Laot, A.Glavieux, and J. Labat,Turbo Equalization:adaptive equalization and channel decoding jointly optimized, IEEE Journal on Selected Areas on Communication, vol.19,no.9,pp.1744-1752,September 2001.
[25]D.Raphaeli and A.Saguy, Reduced complexity APP for turbo equalization, Proc.IEEE Int. Conf.Commun.,2002,vol.3,pp.1940-1943.
[26]张力军,张宗橙,郑宝玉等.数字通信.电子工业出版社.2009.
[27]丁志军.短波数传中Turbo均衡算法研究.西安电子科技大学.2007.
[28]吴莹.高效LDPC编译码及其组合均衡技术在无线通信中的研究.南京航空航天大学.2007.
[2]郭梯云,邬国杨,李建东.移动通信.西安电子科技大学.2005.
[3]Lucky.R.W.,Automatic equalization for digital communication,Bell Syst.Tech.J.,vol 44, pp.547-588,April 1965.
[4] J.G. Proakis, J. H. Miller. An Adaptive Receive for Digital Signaling through Channels with Intersymbol interference. IEEE Trans. Inf Theory, 1969, 15(3):484~97.
[5] Ungerboeck .G ,Theory on the Speed of Convergence in Adaptive Equalizers for Digital Communication. IBM J.Res.Dev, 1972,16(11):546~555.
[6]D.Godard. Channel Equalization Using a Kalman filter for Fast Data Transmission. IBM J. Research and Development,l974 21(5):267~273.
[7]D.D. Falconer,L.Ljung. Application of Fast Kalman Estimation to Adaptive Equalization . IEEE Trans.Commu, 1978 , 26(10): 1439~1446.
[8]戴懿,曾加,郑志航.Turbo码新译码算法.上海交通大学学报,1998,32(6):33~37
[9] Ralf Koetter, Andrew.C.Singer. Turbo Equalization .IEEE,Signal Processing Magazine, 2004:67~81.
[10] M. Tüchler, A. Singer, and R. Koetter, Minimum mean square error equalization using a priori information,IEEE Trans. Signal Processing, 2002, 50(3):673~683.
[11]H. Poor, An Introduction to Signal, Detection and Estimation, 2nded.New York: Springer-Verlag, 1994.
[12]Krishna R.Narayanan,Xiaodong Wang,Guosen Yue. Estimation the PDF of the SIC_MMSE Equalizer Output and Its Applications in Designing LDPC Codes With Turbo Equalization, IEEE Trans.Commun,vol.4,No.1,January 2005.
[13] M. Tuchler, R. Koetter, A. Singer. Turbo equalization: principles and new results.IEEE Trans on Comm, 2002,20(5): 754~767.
[14]Adebisi B,Giovaneli C L,Honary B. Low Complexity Turbo Equalization for Power Line Communications. IEEE Trans.Commun., 2006,50(4):553-559.
[15]郭淑霞,韩棕等.基于无线信道的软干扰抵消Turbo均衡技术研究[J].计算机测量与控制,2009.17(7).
[16] F. Vogelbruch and S. Haar, Low complexity turbo equalization based on soft feedback interference cancellation, IEEE Commun. Lett., vol. 9,pp. 586-588, Jul. 2005.
[17] D. Ampeliotis and K. Berberidis, A new turbo equalizer with linear complexity, in 13th European Signal Processing Conference (EUSIPCO 2005), Antalya,Turkey,September 2005.
[18] K. Berberidis, A. Marava, P. Karaivazoglou and J. Palicot, Robust and Fast Converging Decision Feedback Equalizer Based on a New Adaptive Semi-Blind Channel Estimation Algorithm, in Proc. of the 2001 IEEE GLOBECOM, San Antonio, USA, Nov. 2001.
[19] A.Glavieux,C.Laot,and J. Labat, Turbo equalization over a frequency selective channel, in Proc. Int. Symposium on Turbo codes & relared topics, Brest, France, Sept. 1997,pp.96-102.
[20]徐俊,蒋志红.Turbo均衡的多种算法及其性能比较[J].重庆邮电学院学报,2003,15(1):15-19.
[21]方毅伟.短波通信中Turbo均衡技术的研究.武汉:华中科技大学.2004.
[22]Renato R.Lopes and John R.Barry. The Soft-Feedback Equalizer for Turbo Equalization of Highly Dispersive Channels, IEEE Trans.Commun,vol.54,No.5,May 2006.
[23]杨静国,周新力等.短波信道数字通信中Turbo均衡技术研究.舰船电子工程.Vol.28,No
[24] C.Laot, A.Glavieux, and J. Labat,Turbo Equalization:adaptive equalization and channel decoding jointly optimized, IEEE Journal on Selected Areas on Communication, vol.19,no.9,pp.1744-1752,September 2001.
[25]D.Raphaeli and A.Saguy, Reduced complexity APP for turbo equalization, Proc.IEEE Int. Conf.Commun.,2002,vol.3,pp.1940-1943.
[26]张力军,张宗橙,郑宝玉等.数字通信.电子工业出版社.2009.
[27]丁志军.短波数传中Turbo均衡算法研究.西安电子科技大学.2007.
[28]吴莹.高效LDPC编译码及其组合均衡技术在无线通信中的研究.南京航空航天大学.2007.