基于训练序列的OOFDM采样时钟频率偏差估计算法

doi:10.3969/j.issn.1007-2861.2015.02.011

上海大学学报(自然科学版) ›› 2017, Vol. 23 ›› Issue (1): 138-146.doi: 10.3969/j.issn.1007-2861.2015.02.011

基于训练序列的OOFDM采样时钟频率偏差估计算法

张镇, 宋英雄, 张俊杰, 顿涵, 郭松霖, 薛子威

上海大学特种光纤与光接入网省部共建重点实验室, 上海200072

收稿日期:2015-04-22 出版日期:2017-02-28 发布日期:2017-02-28
通讯作者: 宋英雄(1973—), 男, 研究员, 博士生导师, 博士, 研究方向为光接入网. E-mail: herosf@shu.edu.cn
作者简介:宋英雄(1973—), 男, 研究员, 博士生导师, 博士, 研究方向为光接入网. E-mail: herosf@shu.edu.cn
基金资助:
国家自然科学基金资助项目(61132004, 61275073, 61420106011); 上海市科委重点资助项目(13JC1402600, 14511100100)

Estimation algorithm of sampling clock frequency offset for OOFDM system based on training sequence

ZHANG Zhen, SONG Yingxiong, ZHANG Junjie, DUN Han, GUO Songlin, XUE Ziwei

Key Laboratory of Specialty Fiber Optics and Optical Access Networks, Shanghai University, Shanghai 200072, China

Received:2015-04-22 Online:2017-02-28 Published:2017-02-28

摘要/Abstract

摘要：

研究了光正交频分复用(optical orthogonal frequency division multiplexing, OOFDM)系统中采样时钟同步问题, 提出了一种基于训练序列互相关特性的易于硬件实现的采样时钟频偏估计算法. 算法的主要思想是对接收到的训练序列与本地已知训练序列作互相关, 利用该相关值周期性变化一次产生一个采样点数差的特性, 由少量加法器和一个除法器得到采样时钟频率偏差(sampling clock frequency offset, SCFO)值. 通过在一个强度调制直接检测的光正交频分复用(intensity-modulation and direct-detection-OFDM, IMDD-OFDM)系统上的实验, 验证了该算法具有较好的准确度和抗噪性能.

关键词: 采样时钟同步, 互相关, 训练序列, 光正交频分复用

Abstract:

This paper studies sampling clock synchronization for optical orthogonal frequency division multiplex (OOFDM) systems, and proposes a simple sampling clock frequency offset (SCFO) estimation algorithm for hardware implementation based on crosscorrelation properties of the training sequence. The main idea is as follows. First, correlation between the received training sequence and the known training sequence is obtained, and then sampling clock frequency offset found with a few adders and one divider based on the property that an additional sampling point is introduced when the cross-correlation
value periodically changes a cycle. An optical OFDM system with intensity-modulation and direct-detection (IMDD-OFDM) is set up to show performance of the algorithm. Experimental and simulated results indicate that the algorithm has good accuracy and noise immunity.

Key words: cross-correlation , sampling clock synchronization , training sequence, optical orthogonal frequency division multiplex (OOFDM)

张镇, 宋英雄, 张俊杰, 顿涵, 郭松霖, 薛子威. 基于训练序列的OOFDM采样时钟频率偏差估计算法[J]. 上海大学学报(自然科学版), 2017, 23(1): 138-146.

ZHANG Zhen, SONG Yingxiong, ZHANG Junjie, DUN Han, GUO Songlin, XUE Ziwei. Estimation algorithm of sampling clock frequency offset for OOFDM system based on training sequence[J]. Journal of Shanghai University（Natural Science Edition）, 2017, 23(1): 138-146.

参考文献

[1] Jin X Q,Wei J L, Giddings R P, et al. Experimental demonstrations and extensive comparisons of end-to-end real-time optical OFDM transceivers with adaptive bit and/or power loading [J]. Photonics Journal, 2011, 3(3): 500-511.
[2] Lin B, Li J, Wan Y, et al. Efficient MIMO channel estimation for OFDM-PON based on polarization interleaving and direct detection [C]// National Fiber Optic Engineers Conference. 2013: 1-3.
[3] Duan X, Giddings R P, Bolea M, et al. Real-time experimental demonstrations of software reconfigurable optical OFDM transceivers utilizing DSP-based digital orthogonal filters for SDN PONs [J]. Optics Express, 2014, 22(16): 19674-19685.
[4] 汪敏, 虞礼辉, 冯俊飞, 等. 基于异步时钟高速实时光OFDM收发系统[J]. 上海大学学报(自然科学版), 2013, 19(3): 250-253.
[5] Sliskovic M. Sampling frequency offset estimation and correction in OFDM systems [C]//IEEE International Conference on Electronics, Circuits, and Systems. 2001: 437-440.
[6] Shafiee H, Nourani B, Khoshgard M. Estimation and compensation of frequency offset in DAC/ADC clocks in OFDM systems [C]// IEEE International Conference on Communications. 2004: 2397-2401.
[7] Chen M, He J, Cao Z, et al. Symbol synchronization and sampling frequency synchronization techniques in real-time DDO-OFDM systems [J]. Optics Communications, 2014, 326: 80-87.

[8] 胡登鹏, 张尔扬. 非数据辅助的OFDM系统采样频率同步算法[J]. 信号处理, 2010, 26(6): 956-960.
[9] Fort A, Weijers J W, Derudder V, et al. A performance and complexity comparison of auto-correlation and cross-correlation for OFDM burst synchronization [C]// IEEE International Conference on Acoustics, Speech, and Signal Processing. 2003: 341-344.
[10] Shafik R A, Rahman S, Islam R. On the extended relationships among EVM, BER and SNR as performance metrics [C]// International Conference on Electrical and Computer Engineering. 2006: 408-411.

基于训练序列的OOFDM采样时钟频率偏差估计算法

Estimation algorithm of sampling clock frequency offset for OOFDM system based on training sequence

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