[1]赵光玲,吴乐南.Turbo码的高效调制方案[J].东南大学学报(自然科学版),2001,31(5):1-6.[doi:10.3969/j.issn.1001-0505.2001.05.001]
 Zhao Guangling,Wu Lenan.A High Spectral Efficiency Modulation Scheme for Turbo-Codes[J].Journal of Southeast University (Natural Science Edition),2001,31(5):1-6.[doi:10.3969/j.issn.1001-0505.2001.05.001]
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Turbo码的高效调制方案()
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《东南大学学报(自然科学版)》[ISSN:1001-0505/CN:32-1178/N]

卷:
31
期数:
2001年第5期
页码:
1-6
栏目:
信息与通信工程
出版日期:
2001-09-20

文章信息/Info

Title:
A High Spectral Efficiency Modulation Scheme for Turbo-Codes
作者:
赵光玲 吴乐南
东南大学无线电工程系, 南京 210096
Author(s):
Zhao Guangling Wu Lenan
Department of Radio Engineering, Southeast University, Nanjing 210096, China)
关键词:
Turbo码 16QAM调制 LLR值 log-MAP算法
Keywords:
Turbo-code 16QAM modulation LLR value log-MAP algorithm
分类号:
TN911.22
DOI:
10.3969/j.issn.1001-0505.2001.05.001
摘要:
Turbo码由于其接近香农限的特性而倍受关注,但标准的Turbo码是低码率码,其频带效率低,为了利用Turbo码低误码率的特点,同时又能提高其频带利用率,一个简单的方法是让其与高效率的高阶调制方案M-QAM相结合.本文在高斯信道和瑞利平坦衰落信道条件下对对数域最大后验概率(log-MAP)解码算法进行了研究和修改,使之适合这2种信道和高阶调制方案.通过采用一种实用方法,使得编、解码系统具有通用性,同时推导出精确计算高斯信道下调制码元对数似然值(LLR)的计算公式,并与近似算法进行了比较.仿真结果表明,在2种信道中,该方案具有很高的编码增益,同时频带效率也得到了提高.
Abstract:
Turbo code has won much attention in recent years for the property of near Shannon limit. However, the bandwidth efficiency of Turbo code is low because of its low code rate. In order to use the very low bit error rate (BER) and improve the bandwidth efficiency of Turbo code system, a method by combining the Turbo code with high order modulation scheme such as 16QAM is introduced in this paper. Through careful studying the log-MAP algorithm, some modifications are made to fit in with Gaussian channel, flat Rayleigh fading channel and the MQAM modulation technique. The Turbo codes system is universal because a pragmatic approach is utilized and it is pivotal for VLSI realization. A precise formula of calculating the LLRs is deduced in this paper and a comparison is made. It is shown that the new scheme is of high coding gain and the bandwidth is improved.

参考文献/References:

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[2] Benedetto S,Divsalar D,Montorsi G,et al.Parallel concatenated trellis coded modulation.In:Mcpherson Rod,ed.ICC 1996 Conf Rec.Dallas,Tx USA:IEEE Comm Society,1996.974~978
[3] Viterbi A J,Zehavi E,Padovani R,et al.A pragmatic approach to trellis-coded modulation.IEEE Commun Mag,1989,27(7):11~19
[4] Stephane Le Goff,Glavieux Alain,Claude Berrou.Turbo-codes and high spectral efficiency modulation.In:Thompson C L,ed.Proceedings of ICC ’94.New Orleans,Louisianna:IEEE Comm Society,1994.645~649
[5] Robertson P,Hoeher P,Villebrun E.Optimal and sub-optimal maximum a posteriori algorithms suitable for turbo decoding.European Trans on Telecommun,1997,8:119~125
[6] Hall Eric K,Wilson Stephen G.Design and analysis of turbo codes on Rayleigh fading channels.IEEE Journal on Selected Areas in Commun,1998,16(2):160~174

备注/Memo

备注/Memo:
作者简介:赵光玲,男,1964年生,博士研究生.
基金项目:国家自然科学基金资助项目(60072013).
更新日期/Last Update: 2001-09-20