Photonic Network Communications

, Volume 38, Issue 3, pp 326–342 | Cite as

Performance enhancement of high-capacity coherent DWDM free-space optical communication link using digital signal processing

  • Rajan MiglaniEmail author
  • Jagjit Singh Malhotra
Original Paper


In this paper, 1.28 Tbps (32 × 40 Gbps) high-capacity DWDM-FSO link has been investigated for performance enhancement using coherent detection and digital signal processing (DSP). The DP-16QAM-modulated proposed DWDM-FSO link has been analyzed for both adverse weather and turbulent atmospheric conditions. It is observed that when link is subjected to strong turbulence along with adverse weather conditions, the DSP-aided coherent DWDM-FSO receiver achieves target bit error rate (BER) of 10−4 at signal-to-noise ratio (SNR) of 36.4 dB, while for similar conditions, the SNR requirements for IM/DD-based DWDM-FSO link shoots by 12.8 dB to 49.2 dB. Also, in terms of operational link range, the proposed link even under strong turbulent conditions serves 1.88 km, whereas IM/DD link was restricted to mere 1.12 km for target of BER of 10−4, thus producing a decent range increment of 760 m. The proposed link has been designed and investigated using OptiSystem™ 14.2.


Free-space optical communication Coherent detection Digital signal processing DWDM Atmospheric turbulence Gamma–Gamma channel modeling 



The authors gratefully acknowledge the Department of Electronics and Communication Engineering, D.A.V Institute of Engineering and Technology and I. K. Gujral Punjab Technical University, India, for providing the necessary infrastructure and facilities for this research work. We are also thankful to anonymous reviewers for their invaluable comments and suggestions which have helped to improve the manuscript.


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Copyright information

© Springer Science+Business Media, LLC, part of Springer Nature 2019

Authors and Affiliations

  1. 1.I. K. Gujral Punjab Technical UniversityJalandharIndia
  2. 2.DAVIETJalandharIndia

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