首页 > 论文 > 光学学报 > 36卷 > 8期(pp:806006--1)

串行级联脉冲位置调制码辅助的时隙同步技术

Slot Synchronization Aided by Serial Concatenated Pulse Position Modulation Code System

  • 摘要
  • 论文信息
  • 参考文献
  • 被引情况
  • PDF全文
分享:

摘要

针对深空光脉冲位置调制(PPM)通信,基于最大期望(EM)定时误差估计原理,研究了一种基于串行级联脉冲位置调制(SCPPM)码辅助的光PPM时隙同步的解决方案。由于标准的SCPPM译码方法无法获得EM估计时所需的期望值,因此提出一种将SCPPM译码输出的软信息转换为PPM各时隙期望值的方法。由SCPPM译码输出先进行硬判决,再通过累加模块获得累加器状态;根据该状态选择下一个PPM映射方式,进而获得各PPM时隙的概率及期望;最后利用EM算法预测时钟偏差值从而获得最佳采样点。仿真结果表明,对于2倍PPM时隙频率的异步采样信号,当时钟误差在-0.5~0.5个PPM时隙范围内时,此方法能有效实现PPM时隙同步。

Abstract

Aiming at deep space optical pulse position modulation (PPM) communications, based on the principle of expectation-maximization (EM) timing error estimation, a new solution of optical PPM slot synchronization based on serial concatenated pulse position modulation (SCPPM) code is studied. Due to that the expected value of EM estimation can not be got by the standard SCPPM decoding method, a method to convert the soft information output from SCPPM decoder to the expected value of each PPM slot is proposed. Firstly, the hard decision of output from the SCPPM decoder is made, and the accumulator state through accumulation module is got. Then, a mapping method according to the former accumulator state is chosen, and the probability and expectation of each PPM slot is obtained. Finally, EM algorithm is used to predict the clock offset and then to obtain the best sampling point. According to the simulation results, for the asynchronous sampling signal with two times PPM slot frequency, the proposed method can effectively achieve the PPM slot synchronization under the condition of the clock error among -0.5~0.5 PPM slots.

Newport宣传-MKS新实验室计划
补充资料

中图分类号:TN929.1

DOI:10.3788/aos201636.0806006

所属栏目:光纤光学与光通信

基金项目:国家自然科学基金(61571072,61371096,61275077)

收稿日期:2016-03-14

修改稿日期:2016-04-18

网络出版日期:--

作者单位    点击查看

向劲松:重庆邮电大学通信与信息工程学院, 重庆 400065
吴涛:重庆邮电大学通信与信息工程学院, 重庆 400065
黄胜:重庆邮电大学通信与信息工程学院, 重庆 400065
刘焕淋:重庆邮电大学通信与信息工程学院, 重庆 400065

联系人作者:吴涛(wutao363198897@sina.cn)

备注:吴涛(1989-),男,硕士研究生,主要从事空间光通信方面的研究。

【1】Ren Xin, Li Hongzuo, Wang Yan, et al. Effect for modulation rate of pulsed fiber laser on pulse position modulation[J]. Acta Optica Sinica, 2014, 34(7): 0706002.
任鑫, 李洪祚, 王岩, 等. 脉冲位置调制对脉冲式光纤激光器调制速率的影响[J]. 光学学报, 2014, 34(7): 0706002.

【2】Liu Hongzhan, Liao Renbo, Sun Jianfeng, et al. Performance analysis of new hybrid pulse modulation scheme in optical wireless system[J]. Acta Optica Sinica, 2015, 35(7): 0706004.
刘宏展, 廖仁波, 孙建锋, 等. 无线光通信新型组合脉冲调制性能分析[J]. 光学学报, 2015, 35(7): 0706004.

【3】Rouissat M, Borsali R A, Chikh-Bled M E. AH-MPPM a new modulation scheme for free space optical communication systems[C]. 8th International Conference on High-Capacity Optical Networks and Emerging Technologies, 2013, 35(2): 188-192.

【4】Moision B, Hamkins J. Coded modulation for the deep-space optical channel: serially concatenated pulse-position modulation[R]. The Interplanetary Network Progress Report 42-161, 2005: 1-26.

【5】Noels N, Lottici V, Dejonghe A, et al. A theoretical framework for soft-information-based synchronization in iterative (Turbo) receivers[J]. EURASIP Journal on Wireless Communications and Networking, 2005: 117-129.

【6】Man X, Zhai H T, Yang J, et al. Improved code-aided symbol timing recovery with large estimation range for LDPC-coded systems[J]. IEEE Communications Letters, 2013, 17(5): 1008-1011.

【7】Zhou Xiangchao, Zhao Danfeng, Xue Rui. Soft timing synchronization algorithm for LDPC codes on GF(q) in deep space communication[J]. Journal of Harbin Institute of Technology, 2014, 46(3): 110-114.
周相超, 赵旦峰, 薛睿. 深空通信系统中高阶LDPC码的软定时同步算法[J]. 哈尔滨工业大学学报, 2014, 46(3): 110-114.

【8】Zhao Danfeng, Zhou Xiangchao, Qian Jinxi, et al. Code-aided carrier synchronization for LDPC-MSK systems in presence of residual frequency offset[J]. Systems Engineering and Electronics, 2012, 34(9): 1900-1905.
赵旦峰, 周相超, 钱晋希, 等. 残留频偏下LDPC-MSK系统码辅助载波同步算法[J]. 系统工程与电子技术, 2012, 34(9): 1900-1905.

【9】Shi Zhiping, Tang Fajian, Yan Hui, et al. Joint assisted carrier synchronization algorithm by pilot and code at extremely low SNR[J]. Journal of Electronies & Information Technology, 2011, 33(10): 2506-2510.
史治平, 唐发建, 晏辉, 等. 极低信噪比下的导频联合编码辅助载波同步算法[J]. 电子与信息学报, 2011, 33(10): 2506-2510.

【10】Quirk K J, Srinivasan M. Optical PPM demodulation form slot-sampled photon counting detectors[C]. IEEE Military Communications Conference, 2013: 1634-1638.

【11】Liu Lei, Xiao Jiangnan, Tang Jin, et al. Experimental research on timing recovery of a differential quadrature phase shift keying coherent optical transmission system based on an improved Gardner algorithm[J]. Acta Optica Sinica, 2013, 33(4): 0406002.
刘磊, 肖江南, 唐进, 等. 相干光差分正交相移键控系统中改进的Gardner定时恢复方法实验研究[J]. 光学学报, 2013, 33(4): 0406002.

【12】Zhang Dingchen, Zhou Xiaolin, Du Jianhong. PPM iterative soft demodulation algorithm in free-space optical communication[J]. Computer Engineering, 2013, 39(4): 1-4.
张鼎臣, 周小林, 杜建红. 自由空间光通信中的PPM迭代软解调算法[J]. 计算机工程, 2013, 39(4): 1-4.

【13】Hu Hao, Wang Hongxing, Xu Jianwu, et al. Bit interleaved product coded pulse position modulation with iterative demodulation for free-space optical communication[J]. Acta Optica Sinica, 2011, 31(8): 0806004.
胡昊, 王红星, 徐建武, 等. 无线光通信中一种迭代解调的比特交织乘积编码脉冲位置调制[J]. 光学学报, 2011, 31(8): 0806004.

您的浏览器不支持PDF插件,请使用最新的(Chrome/Fire Fox等)浏览器.或者您还可以点击此处下载该论文PDF