20 June 2001 Significance of chirp parameter for direct-detection free-space laser communication
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Proceedings Volume 4272, Free-Space Laser Communication Technologies XIII; (2001) https://doi.org/10.1117/12.430784
Event: Photonics West 2001 - LASE, 2001, San Jose, CA, United States
We investigate the influence of chirp on free-space laser communication systems employing optically preamplified direct-detection receivers. We analyze the changes of receiver sensitivities in the presence of chirp and optimize both the optical and electrical receiver bandwidth with regard to sensitivity. For return-to-zero (RZ) coding with 33% duty cycle the receiver sensitivity decreases due to spectral broadening of the received signal by typically 3 dB when the chirp parameter amounts to alphaequals5. For optimized bandwidths, the penalty can be kept as low as 1 dB. In contrast, in the case of non-return-to-zero coding, chirp can reduce inter-symbol interference (ISI), thus improving receiver performance due to a pulse compression effect. The gain in sensitivity can be as large as to 1.8 dB when the magnitude of the chirp is alphaequals4. A larger chirp decreases the receiver sensitivity. In the case of NRZ, the optimum receiver bandwidths are quite insensitive with regard to chirp.
© (2001) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Martin M. Strasser, Martin M. Strasser, Peter J. Winzer, Peter J. Winzer, Martin Pfennigbauer, Martin Pfennigbauer, Walter R. Leeb, Walter R. Leeb, "Significance of chirp parameter for direct-detection free-space laser communication", Proc. SPIE 4272, Free-Space Laser Communication Technologies XIII, (20 June 2001); doi: 10.1117/12.430784; https://doi.org/10.1117/12.430784

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