吉林大学学报(工学版) ›› 2022, Vol. 52 ›› Issue (11): 2728-2734.doi: 10.13229/j.cnki.jdxbgxb20210352

• 通信与控制工程 • 上一篇    

一种正交频分复用定时同步算法及其硬件实现优化

潘磊1,2,3(),陈岚1,朱胜利4,童雯艳5   

  1. 1.中国科学院 微电子研究所,北京 100029
    2.中国科学院大学,北京 100039
    3.三维及纳米集成电路设计自动化技术北京市重点实验室,北京 100029
    4.北京云圣智能科技有限责任公司,北京 100007
    5.辽宁工贸学校,沈阳 110122
  • 收稿日期:2021-04-22 出版日期:2022-11-01 发布日期:2022-11-16
  • 作者简介:潘磊(1979-),男,高级工程师,博士. 研究方向:物联网通信终端架构设计,通信终端SOC芯片设计.E-mail: panlei@ime.ac.cn
  • 基金资助:
    国家重点研发计划项目(2019YFB2102400)

A new algorithm for OFDM timing synchronization and hardware implementation optimization

Lei PAN1,2,3(),Lan CHEN1,Sheng-li ZHU4,Wen-yan TONG5   

  1. 1.Institute of Microelectronics,Chinese Academy of Sciences,Beijing 100029,China
    2.University of the Chinese Academy of Sciences,Beijing 100039,China
    3.Beijing Key Laboratory of Three Dimensional and Nanometer Integrated Circuit Design Automation Technology,Beijing 100029,China
    4.Beijing Ikingtec Intelligent Technology Co. ,Ltd. ,Beijing 100007,China
    5.Liaoning Industry and Trade School,Shenyang 110122,China
  • Received:2021-04-22 Online:2022-11-01 Published:2022-11-16

摘要:

针对在多径信道环境中由于多径反射导致正交频分复用(OFDM)符号的循环前缀会受到符号间干扰(ISI)的问题,本文提出一种时域定时同步算法:相关峰斜率检测算法。该算法通过对相关峰斜率的检测确定最后一径位置,估计出多径信道弥散长度,从而使后继傅立叶变换(FFT)开窗位置避开ISI。与经典算法对比,本算法可更好地避免ISI,特别是在CT-8信道中全部避开ISI。另外,针对类似NB-IOT采用了OFDM技术的低成本物联网通信系统,对算法进行了简化,可降低物联网终端基带芯片实现的代价,减少终端成本。

关键词: 正交频分复用, 定时同步, 相关峰斜率, 数字集成电路设计优化, 基带芯片

Abstract:

This article introduces an algorithm for orthogonal frequency divisition multiplexing(OFDM) timing synchronization—correlated peak slope detection algorithm. In a multipath channel environment, due to multipath reflection, the front part of the cyclic prefix that OFDM complies with will be affected by Inter Symbol Interference(ISI). This paper innovatively proposes a time-domain timing synchronization algorithm. The algorithm determines the arrival position of the last path by detecting the slope of the correlation peak, and estimates the dispersion length of the multipath channel, so that the subsequent fast Fourier transform(FFT) window position avoids the ISI, and provides a reference value for the selection of filter coefficients for channel estimation. This algorithm is also very suitable for application in multipath channels with equal strength and two paths. Finally, the algorithm was simulated with MATLAB and compared with the classic algorithm, which proved that the algorithm can better avoid ISI in the case of low signal-to-noise ratio. In addition, for a low-cost IoT communication system similar to NB-IOT that uses OFDM technology, this article simplifies the algorithm, which can reduce the cost of implementing the baseband chip of the IoT terminal and reduce the cost of the terminal.

Key words: orthogonal frequency divisition multiplexing(OFDM), timing synchronization, correlated peak slope, digital IC design optimization, base band ASIC

中图分类号: 

  • TN929.5

图1

多径信道对OFDM符号在时间轴上的影响"

图2

PN序列组成的信标"

图3

无噪声、无多普勒频偏的等强两径信道情况下的理想相关峰"

图4

仿真用发射数据结构"

表1

TU信道模型"

路径序号时延/μs增益/dB
10-3
20.20
30.5-2
41.6-6
52.3-8
65.0-10

图5

在TU信道下定时概率统计比较"

表2

CT-8信道模型"

路径序号时延/μs增益/dB
10-18
21.80
32.0-20
43.6-20
57.5-10
631.80

图6

在CT-8信道下定时概率统计比较"

表3

随机信道模型约束条件"

随机信道条件数值
信噪比(SNR)/dB10
多径数/径1~10
延时的随机范围/μs0~30
增益的随机范围/dB0~-20

图7

随机信道本算法定时位置统计"

表4

随机信道下非最后一径定时开窗能量损失统计"

早于最后一径的采样点数损失能量百分比/%
32.3915
273.1014
1041.7351

图8

随机信道S.C.A算法定时位置统计"

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