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8 - Modern communications designs for FOC/FSOC applications

Published online by Cambridge University Press:  05 February 2013

Sherman Karp  and
Larry B. Stotts
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Summary

Introduction

This chapter discusses some of the key aspects of the signal modulation and coding schemes used in FOC and FSOC systems today. Most notably, we will review the use of return-to-zero (RZ) and non-return-to-zero (NRZ) in coding the information streams and see their effect on systems performance, as well as receiver sensitivity.

Modern signal modulation schemes

Let us begin with some definitions.

Return-to-zero (RZ)

RZ describes a signal modulation technique where the signal drops (returns) to zero between each incoming pulse. The signal is said to be “self-clocking”. This means that a separate clock signal does not need to be sent alongside the information signal to synchronize the data stream. The penalty is the system uses twice the bandwidth to achieve the same data-rate as compared to non-return-to-zero format (see next definition).

Although any RZ scheme contains a provision for synchronization, it still has a DC component, resulting in “baseline wander” during long strings of “0” or “1” bits, just like the line code non-return-to-zero. This wander is also known as a “DC droop”, resulting from the AC coupling of such signals

Type
Chapter
Information
Fundamentals of Electro-Optic Systems Design
Communications, Lidar, and Imaging
 , pp. 141 - 150
Publisher: Cambridge University Press
Print publication year: 2012

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References

Zhang, S.. Advanced optical modulation formats in high-speed lightwave systems. Thesis, The University of Kansas (2004).Google Scholar
Gnauck, A. H. and Winzer, P. J.. Optical phase-shift-keyed transmission. Journal of Lightwave Technology, 23(1) (2005).Google Scholar
Henry, P. S.. Error-rate performance of optical amplifiers. In Proceedings of the OFC 1989, Houston, TX (1989), Paper THK3.Google Scholar
Humblet, P. A. and Azizoglu, M.. On the bit error rate of lightwave systems with optical amplifiers. Journal of Lightwave Technology, 9(11) (1991), pp. 1576–1582.CrossRefGoogle Scholar
Jacobsen, G.. Noise in Digital Optical Transmission Systems. Boston, MA: Artech House (1994), Ch. 2.Google Scholar
Chinn, S. R., Boroson, D. M. and Livas, J. C.. Sensitivity of optically preamplified DPSK receivers with Fabry-Perot filters. Journal of Lightwave Technology, 14(3) (1996), pp. 370–376.CrossRefGoogle Scholar
Xu, C., Liu, X. and Wei, X.. Differential phase-shift keying for high spectral efficiency optical transmissions. IEEE Journal of Selected Topics in Quantum Electronics, 10(2) (2004).CrossRefGoogle Scholar
Majumdar, A. K. and Ricklin, J. C.. Free-Space Laser Communications; Principles and Advances. Springer, New York (2008).CrossRefGoogle Scholar
Caplan, D. O., Robinson, B. S., Stevens, M. L., Boroson, D. M. and Hamilton, S. A.. High-rate photon-efficient laser communications with near single photon/bit receiver sensitivities. In Optical Fiber Conference (OFC), 2006.
Peeble, Jr P. Z.. Digital Communications Systems. Prentice Hall, Edgewood, NJ (1987).Google Scholar
Boroson, D. M.. Optical Communications, A Compendium of Signal Formats, Receiver Architectures, Analysis Mathematics, and Performance Comparison. MIT (2005).Google Scholar
Mizuochi, T. et al.. Forward error correction based on block turbo code with 3-bit soft decision for 10-Gbps optical communication systems. IEEE Photonics Technology Letters, 16 (2004), pp. 1579–1581.Google Scholar
Juarez, J. C., Young, D. W., Sluz, J. E. and Stotts, L. B.. High-sensitivity DPSK receiver for high-bandwidth free-space optical communication links. Optics Express, 19(11) (2011), pp. 10789–10796.CrossRefGoogle ScholarPubMed
Pfennigbauer, M., Strasser, M. M., Pauer, M. and Winzer, P. J.. Dependence of optically preamplified receiver sensitivity on optical and electrical filter bandwidths – measurement and simulation. IEEE Photonics Technology Letters, 14(6) (2002), pp. 831–833.CrossRefGoogle Scholar

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