Study on a low complexity adaptive modulation algorithm in OFDM-ROF system with sub-carrier grouping technology

Chong Xin Liu, Bo Liu, Li Jia Zhang, Xiang Jun Xin, Qing Hua Tian, Feng Tian, Yong Jun Wang, Lan Rao, Yaya Mao, Deng Ao Li

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review

1 Citation (Scopus)

Abstract

During the last decade, the orthogonal frequency division multiplexing radio-over-fiber (OFDM-ROF) system with adaptive modulation technology is of great interest due to its capability of raising the spectral efficiency dramatically, reducing the effects of fiber link or wireless channel, and improving the communication quality. In this study, according to theoretical analysis of nonlinear distortion and frequency selective fading on the transmitted signal, a low-complexity adaptive modulation algorithm is proposed in combination with sub-carrier grouping technology. This algorithm achieves the optimal performance of the system by calculating the average combined signal-To-noise ratio of each group and dynamically adjusting the origination modulation format according to the preset threshold and user's requirements. At the same time, this algorithm takes the sub-carrier group as the smallest unit in the initial bit allocation and the subsequent bit adjustment. So, the algorithm complexity is only 1 /M (M is the number of sub-carriers in each group) of Fischer algorithm, which is much smaller than many classic adaptive modulation algorithms, such as Hughes-Hartogs algorithm, Chow algorithm, and is in line with the development direction of green and high speed communication. Simulation results show that the performance of OFDM-ROF system with the improved algorithm is much better than those without adaptive modulation, and the BER of the former achieves 10e1 to 10e2 times lower than the latter when SNR values gets larger. We can obtain that this low complexity adaptive modulation algorithm is extremely useful for the OFDM-ROF system.

Original languageEnglish
Title of host publication2017 International Conference on Optical Instruments and Technology
Subtitle of host publicationOptoelectronic Devices and Optical Signal Processing
EditorsFabien Bretenaker, Jian Chen, Yi Dong
PublisherSPIE
ISBN (Electronic)9781510617452
DOIs
Publication statusPublished - 2018
Externally publishedYes
Event2017 International Conference on Optical Instruments and Technology: Optoelectronic Devices and Optical Signal Processing - Beijing, China
Duration: 28 Oct 201730 Oct 2017

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
Volume10617
ISSN (Print)0277-786X
ISSN (Electronic)1996-756X

Conference

Conference2017 International Conference on Optical Instruments and Technology: Optoelectronic Devices and Optical Signal Processing
Country/TerritoryChina
CityBeijing
Period28/10/1730/10/17

Keywords

  • Adaptive modulation
  • Radio-over-fiber
  • Signal-To-noise ratio
  • Sub-Carrier grouping technology
  • orthogonal frequency division multiplexing

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Cite this

Liu, C. X., Liu, B., Zhang, L. J., Xin, X. J., Tian, Q. H., Tian, F., Wang, Y. J., Rao, L., Mao, Y., & Li, D. A. (2018). Study on a low complexity adaptive modulation algorithm in OFDM-ROF system with sub-carrier grouping technology. In F. Bretenaker, J. Chen, & Y. Dong (Eds.), 2017 International Conference on Optical Instruments and Technology: Optoelectronic Devices and Optical Signal Processing Article 106170Q (Proceedings of SPIE - The International Society for Optical Engineering; Vol. 10617). SPIE. https://doi.org/10.1117/12.2295334