基于OFDM的大气激光通信湍流抑制关键技术研究

郭倩,宋鹏,张周强,等. 基于OFDM的大气激光通信湍流抑制关键技术研究[J]. 光电工程,2020,47(3):190619. doi: 10.12086/oee.2020.190619
引用本文: 郭倩,宋鹏,张周强,等. 基于OFDM的大气激光通信湍流抑制关键技术研究[J]. 光电工程,2020,47(3):190619. doi: 10.12086/oee.2020.190619
Guo Q, Song P, Zhang Z Q, et al. Research on the key technology of turbulence suppression for atmospheric optical laser communication based on OFDM[J]. Opto-Electron Eng, 2020, 47(3): 190619. doi: 10.12086/oee.2020.190619
Citation: Guo Q, Song P, Zhang Z Q, et al. Research on the key technology of turbulence suppression for atmospheric optical laser communication based on OFDM[J]. Opto-Electron Eng, 2020, 47(3): 190619. doi: 10.12086/oee.2020.190619

基于OFDM的大气激光通信湍流抑制关键技术研究

  • 基金项目:
    国家自然科学基金资助项目(61701384);陕西省教育厅科研计划基金资助项目(18JK0341);西安市科技局科技创新基金资助项目(201805030YD8CG14(12))
详细信息
    作者简介:
    通讯作者: 郭倩, E-mail: guoqianyun@126.com
  • 中图分类号: TN929.1

Research on the key technology of turbulence suppression for atmospheric optical laser communication based on OFDM

  • Fund Project: Supported by National Natural Science Foundation of China (61701384), Scientific Research Program Fund of Education Department of Shaanxi Province (18JK0341), and Xi′an Science and Technology Bureau Science and Technology Innovation Fund (201805030YD8CG14 (12))
More Information
  • 文章在分析无线激光通信(FSO)存在两种主要的大气信道问题的基础上,针对激光大气信道问题尤其是在复杂湍流环境下的频率选择性衰落问题和多径效应问题,提出了基于正交频分复用(OFDM)的湍流效应抑制方法,构建了FSO-OFDM系统,研究了该系统的基带模型以及信号的多载波调制与解调方法。分析了无线激光通信中存在复杂湍流环境下的大气信道问题,讨论了大气湍流影响下的平面波激光通信系统模型,建立了大气湍流影响下对数正态湍流通道的高斯光束空间光通信系统模型,推导了光波强度的概率密度函数,研究了利用信噪比概率密度函数分析各种大气湍流效应对系统性能影响的方法; 设计了无线光通信系统的OFDM多载波调制方案,构建了FSO-OFDM系统基带模式模型,并基于该模型研究了其信号的调制与解调原理。最后,采用MATLAB编程实现FSO-OFDM系统,对多径干扰下的FSO通信系统进行仿真实验,进行了不同保护间隔下的误码率特性实验,验证了FSO-OFDM系统具有很强的抗多径干扰和频谱选择性衰落能力以及良好的BER性能,可有效解决码间干扰大、链路不可靠的问题,具有非常广泛的应用前景和使用价值。

  • Overview: In order to support higher information transmission rate, improve the system error characteristics, solve the problems of frequency selective fading and multipath effect of the wireless optical communication system in complex turbulent environment, improve laser atmospheric channel signal transmission problems, based on orthogonal frequency division multiplexing technology, the FSO-OFDM system was built, the multicarrier modulation, modulation and demodulation, etc used this system were studied. Firstly, the turbulence effect, which is a bottleneck problem restricting the application of atmospheric laser communication, was discussed in detail. Then, on the basis of Kolmogorov spectrum model, the plane wave model was studied. By using the modified Rytov method, the spatial optical communication system model of Gaussian beam under log-normal turbulence channel was established, and the probability density function of the system light wave intensity was derived. Then, the OFDM multi-carrier modulation scheme of the wireless optical communication system was designed, the baseband mode model of the FSO-OFDM system was constructed, and the modulation and demodulation of the signal were studied using this model. When the signal of the binary signal source was sent out, it was encoded and modulated to the series-and-conversion module for series-and-conversion, followed by IFFT exchange. After digital-to-analog conversion and filtering, electro-optical conversion was carried out, which becomes the signal s(t) modulated by OFDM. After passing through the atmospheric channel, the signal was sent to the receiving module of the FSO-OFDM system, which is photoelectric converted, low-pass filtering, and then converted by mode/number to restore the orthogonality of the subcarrier. After FFT and string/combination conversion, the signal was restored to the signal before OFDM modulation. After demodulation and decoding, the original input signal was restored. Finally, MATLAB programming was adopted to realize the FSO-OFDM system. Simulation experiments were carried out on the FSO communication system under multi-path interference. Under the same bandwidth condition, the average bit error rate performance of the single-carrier wireless optical communication system and the FSO-OFDM communication system were simulated, respectively. Compared with the traditional single-carrier system, the OFDM system improves the atmospheric channel transmission of laser signal and the information transmission rate. FSO-OFDM system has a strong ability to resist multi-path interference and spectrum selective fading, as well as a good BER performance. It provides a technical method to break through the bottleneck of optical communication and has a very wide application prospect and value.

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  • 图 1  大气环境与无线光学系统性能之间的关系

    Figure 1.  Relationship between atmospheric environment and wireless optical system performance

    图 2  大气信道湍流涡旋

    Figure 2.  Turbulent vortices in atmospheric channels

    图 3  Richardson湍流级串图

    Figure 3.  Richardson turbulence cascade

    图 4  OFDM调制原理

    Figure 4.  Modulation principle of OFDM

    图 5  OFDM多载波并行传输原理图

    Figure 5.  Principle diagram of OFDM multi-carrier parallel transmission

    图 6  FSO-OFDM系统基带模型图

    Figure 6.  Baseband model of the FSO-OFDM system

    图 7  FSO-OFDM系统信号的调制与解调

    Figure 7.  Signal modulation and demodulation of FSO-OFDM system

    图 8  不同载波数下的误码率特性曲线

    Figure 8.  Bit error rate characteristics under different carrier numbers

    图 9  不同保护间隔下的误码率特性曲线

    Figure 9.  Bit error rate characteristic curves under different protection intervals

  • [1]

    柯熙政, 王松.部分相干Airy光束在大气湍流中的光强演化[J].光子学报, 2017, 46(7): 0701001. http://d.old.wanfangdata.com.cn/Periodical/gzxb201707001

    Ke X Z, Wang S. Evolution of the intensity of partially coherent airy beam in atmospheric turbulence[J]. Acta Photonica Sinica, 2017, 46(7): 0701001. http://d.old.wanfangdata.com.cn/Periodical/gzxb201707001

    [2]

    Lukin V P, Pokasov V V. Optical wave phase fluctuations[J]. App. Opt, 1981, 20(1):421-135. http://d.old.wanfangdata.com.cn/NSTLQK/NSTL_QKJJ0214287072/

    [3]

    Kumar R S P, Khan M A J, Nitesh G. Performance analysis of a free space optics link with multiple transmitters/receivers[J]. International Journal for Scientific Research & Development, 2012, 13(3): 254-258.

    [4]

    赵黎, 朱彤, 刘智港, 等.一种兼顾照明与通信的环形光源布局模型[J].光电工程, 2018, 45(7): 170503. doi: 10.12086/oee.2018.170503

    Zhao L, Zhong T, Liu Z G, et al. An annular light source layout model for both lighting and communication reliability[J]. Opto-Electronic Engineering, 2018, 45(7): 170503. doi: 10.12086/oee.2018.170503

    [5]

    苏彩霞, 宋鹏, 孟超, 等.无线紫外光通信脉冲展宽测距方法[J].西安工程大学学报, 2019, 33(2): 161-167. http://d.old.wanfangdata.com.cn/Periodical/xbfzgxyxb201902008

    Su C X, Song P, Meng C, et al. The pulse broadening ranging method of wireless ultraviolet optical communication[J]. Journal of Xi'an Polytechnic University, 2019, 33(2): 161-167. http://d.old.wanfangdata.com.cn/Periodical/xbfzgxyxb201902008

    [6]

    廖天河, 刘伟, 高穹.不同形状激光波束在大气中传输的湍流效应[J].红外与激光工程, 2015(S1):41-45. http://d.old.wanfangdata.com.cn/Periodical/hwyjggc2015z1008

    Liao T H, Liu W, Gao Q. Turbulent effects of laser beams of different shapes in the atmosphere[J]. Infrared and Laser Engineering, 2015(S1): 41-45. http://d.old.wanfangdata.com.cn/Periodical/hwyjggc2015z1008

    [7]

    Švihlík J, Krbcova Z, Tran Q V, et al. Stochastic and analytic modeling of atmospheric turbulence in image processing[J]. Proceedings of SPIE - The International Society for Optical Engineering. Applications of Digital Image Processing XLI, 2018: 10752.

    [8]

    Torrieri D J. Principles of Spread-Spectrum Communication Systems[M]. 3rd ed. Cham: Springer, 2015.

    [9]

    Wang Y, Wang D L, Ma J. On the performance of coherent OFDM systems in free-space optical communications[J]. IEEE Photonics Journal, 2015, 7(4): 7902410.

    [10]

    石蒙, 张梦洁, 迟楠.基于脉冲幅度调制的两发一收可见光通信系统[J].光电工程, 2019, 46(5): 180306. doi: 10.12086/oee.2019.180306

    Shi M, Zhang M J, Chi N. Two input one output visible light communication system based on pulse amplitude modulation[J]. Opto-Electronic Engineering, 2019, 46(5): 180306. doi: 10.12086/oee.2019.180306

    [11]

    吴鹏飞, 贾璐瑶.西安地区大气相干长度的实验测量及分析[J].激光与光电子学进展, 2019, 57(9): 090101.

    Wu P F, Jia L Y. Experimental analysis of atmospheric coherence length measurement in Xi'an area[J]. Laser & Optoelectronics Progress, 2019, 57(9): 090101.

    [12]

    Singhal P, Gupta P, Rana P. Basic concept of free space optics communication (FSO): an overview[C]//Proceedings of 2015 International Conference on Communications and Signal Processing (ICCSP), Melmaruvathur, 2015: 0439-0442.

    [13]

    Khare S, Sahayam N. Analysis of free space optical communication system for different atmospheric conditions & modulation techniques[J]. International Journal of Modern Engineering Research (IJMER), 2012, 2(6): 4149-4152.

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出版历程
收稿日期:  2019-10-15
修回日期:  2019-12-24
刊出日期:  2020-03-01

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