-
发射源的高度扫频线性是调频连续波激光雷达实现高精确测量的必备条件．针对目前基于电流调制分布式反馈半导体激光器产生的调频连续波信号存在扫频非线性问题，本文提出了基于前馈神经网络的扫频非线性预失真方案．该方案首先实验获取分布式反馈半导体激光器在调制电流为锯齿波情形下输出的时频曲线；将锯齿波调制电流作为输入，时频曲线作为输出，基于前馈神经网络获取输入到输出的非线性映射关系；接下来，利用反向传播算法生成能补偿分布式反馈半导体激光器输出非线性的预失真调制电流波形．我们针对调制电流频率处于1 kHz~10 kHz的情形进行了实验研究，结果表明：采用基于前馈神经网络的扫频非线性矫正方案后，分布式反馈半导体激光器所产生的调频连续波信号的扫频非线性从之前的10-3量级降低到10-5量级；残差均方根值从之前的百MHz量级降低到十MHz量级．本文提出的扫频非线性预失真校正方案有望为高精度的调频连续波激光雷达系统的扫频信号线性化技术提供新思路．To address the frequency sweeping nonlinearity of frequency-modulated continuous-wave signals generated by a current-modulated distributed feedback laser diode, we propose and experimentally demonstrate a pre-distortion method based on a feedforward neural network. For such a method, the beat frequency signals of the distributed feedback laser diode under a sawtooth-waveform current modulation are experimentally obtained first, and then the time-frequency curves of the distributed feedback laser diode output are obtained by performing a Hilbert transform on the beat signals. Next, a three-layer feedforward neural network with 10, 5, and 3 hidden-layer neurons is constructed. By taking the driving current and the time-frequency curves as the input and output of the feedforward neural network, respectively, the nonlinear mapping relationship between them is established. Finally, a backpropagation algorithm is utilized to obtain the pre-distortion modulation current. Taking such a current under the modulation frequency from 1 kHz to 10 kHz to drive the DFB-LD, the performance of the generated FMCW signals is analyzed. We use nonlinear regression coefficients and residual root mean square values to characterize the performance. For the modulation frequency set at 4 kHz, the frequency sweeping nonlinearity and the residual root mean square value are reduced from 5.29×10-3 and 281 MHz to 1.77×10-5 and 15.15 MHz, respectively. For the modulation frequency fixed at 6 kHz, the proposed scheme reduced the frequency sweeping nonlinearity from 5.58×10-3 to 1.52×10-5 and the residual root mean square from 251.98 MHz to 12.17 MHz. Across the entire tested frequency range from 1 kHz to 10 kHz, the nonlinearity remained stable at ~10-5 after adopting the pre-distortion scheme, with RMS values consistently below 20 MHz. The proposed method is expected to provide a new scheme for the linearization technology of the sweep signal in high-precision frequency-modulated continuous-wave light detection and ranging systems.
-
Keywords:
- Frequency sweeping nonlinearity /
- Feedforward neural network /
- Pre-distortion /
- Backpropagation algorithm
-
[1] Golconda S 2010 Ph. D. Dissertation (Lafayette: University of Louisiana at Lafayette)
[2] Bețco D, Pârvu P V, Ciudin S 2024 Acta Astronaut. 216 55
[3] Behera L, Agarwal S, Sandhan T, Sharma P, Kumar A, Ranjan A, Watsa S, Singh A, Kasina J S 2025 Int. J. Intell. Unmanne 13 92
[4] Rablau C 2019 Fifteenth Conference on Education and Training in Optics and Photonics: ETOP 2019 Quebec City, Quebec, Canada, May 21-24, 2019 p11143_138
[5] Bhardwaj A, Sam L, Bhardwaj A, Martín-Torres F J 2016 Remote Sens. Environ. 177 125
[6] Wang Q P, Xia G Q, Xie Y K, Ou P, He C T, Hu S, Zhang F L, Zhao M R, Wu Z M 2024 IEEE J. Quant. Elect. 60 2200408
[7] Liang H, Ying K, Wang D Wei J J, Li X, Pi H Y, Wei F, Cai H W 2021 Chinese J. Lasers 48 1606001 (in Chinese) [梁虹, 应康, 王迪, 魏金金, 李璇, 皮浩洋, 魏芳, 蔡海文 2021 中国激光 48 1606001]
[8] Yang J W, Meng Y, Hu X L, Yang T X, Wang Z Y, Jia D F, Ge C F 2024 J. Lightw. Technol. 42 1870
[9] Liu C X, Guo Y Y, Xu R Y, Lu L J, Li Y, Chen J P, Zhou L J 2024 Laser Photon. Rev. 18 2300882
[10] Zhou P, Zhang R H, Li N Q, Jiang Z D, Pan S L 2022 J. Lightw. Technol. 40 2862
[11] Yao Z Y, Mauldin T, Hefferman G, Wei T 2019 IEEE J. Sel. Top. Quant. Electron. 25 1502605
[12] Na Q X, Xie Q J, Zhang N, Zhang L X, Li Y Z, Chen B S, Peng T, Zuo G M, Zhuang D W, Song J F 2023 Opt. Laser Eng. 164 107523
[13] Knipp S 2018 M. S. Dissertation (Kingston: University of Rhode Island)
[14] Lin C X, Wang Y F, Tan Y D 2023 J. Lightw. Technol. 41 2846
[15] Baumann E, Giorgetta F R, Coddington I, Sinclair L C, Knabe K, Swann W C, Newbury N R 2013 Opt. Lett. 38 2026
[16] Xie W L, Meng Y X, Feng Y X, Zhou H J, Zhang L, Wei W, Dong Y 2021 Opt. Express 29 604
[17] Satyan N, Vasilyev A, Rakuljic G, Leyva V, Yariv A 2009 Opt. Express 17 15991
[18] Satyan N, Vasilyev A, Rakuljic G, White J O, Yariv A 2012 Opt. Express 20 25213
[19] Zhang X S, Pouls J, Wu M C 2019 Opt. Express 27 9965
[20] Cao X Y, Wu K, Li C, Zhang G J, Chen J P 2021 J. Opt. Soc. Am. B, 38 D8
[21] Li P, Zhang Y T, Yao J Q 2022 Remote Sens. 14 3455
[22] Jiang Y C, Hu M, Xu M M, Li H Z, Zhou X F, Bi M H, Pan S Q, Liu C 2024 IEEE J. Quant. Elect. 60 1400107
[23] Fang C, Ruan Y X, Guo Q H, Yu Y G 2025 Opt. Laser & Technol. 180 111449
计量
- 文章访问数: 40
- PDF下载量: 0
- 被引次数: 0
下载:
