一种物理层网络编码系统的符号时钟估计算法  

Algorithm for Symbol Timing Estimation in Physical-Layer Network Coding System

作　　者：党小宇[1] 李强[2] 顾晓宇[1] 虞湘宾[1] Dang Xiaoyu;Li Qiang;Gu Xiaoyu;Yu Xiangbin(College of Electronic Information Engineering,Nanjing University of Aeronautics and Astronautics,Nanjing,210016,China;College of Electronic Information Engineering,South China University of Technology^Guangzhou,510641,China)

机构地区：[1]南京航空航天大学电子信息工程学院,南京210016 [2]华南理工大学电子信息工程学院,广州510641

出　　处：《数据采集与处理》2018年第2期215-222,共8页Journal of Data Acquisition and Processing

基　　金：国家自然科学基金(61571224;61571225)资助项目;江苏六大高峰人才资助项目

摘　　要：近年来,物理层网络编码(Physical-layer network coding,PNC)作为一种全新的数字通信方式引起了广泛的研究兴趣。与多数数字通信系统类似,符号时钟在PNC中起着至关重要的作用,然而已有研究结果多假设符号时钟完全已知,对PNC的时钟估计研究较少。针对这一现状,本文基于最大似然估计准则,提出一种基于正交训练序列的低过采样率(每个码元的采样点数)的时钟估计算法,该时钟估计算法具有采样速率低和估计精度高的双重优势。仿真表明,在相同过采样率,信噪比5dB的条件下,均方误差性能比已知的优选采样点算法约提升一个数量级。Recently,physical-layer network coding(PNC),a novel digital communication system,has aroused extensive interest of researchers.Similar to most other digital communication systems,the symbol timing plays an indispensable role in PNC.The existing research results,however,usually assume the symbol timing is fully known and rarely discuss the problem of symbol synchronization for PNC.In this paper,in view of the present situation,according to the maximum-likelihood estimation criterion we propose a new algorithm with a low oversampling factor(samples per symbol)based on the orthogonal training sequences.The proposed algorithm has the double advantage of a low sampling rate and high precision.It is shown by simulations that with a same oversampling factor,the proposed algorithm offers up to a 10-fold increase in the mean square error(MSE)performance over the conventional optimum sample(OS)algorithm for signal-noise ratio(SNR)of 5 dB.

关 键 词：物理层网络编码 双向中继信道 符号时钟估计 脉冲形状 过采样率 

分 类 号：TN919.3[电子电信—通信与信息系统]