Channel estimation for free-space optical communications: preliminary experimental results and analysis

Autor: Akira Ishimaru, James A. Ritcey, Yasuo Kuga, Stephen M. Hammel, Colin N. Reinhardt, Dimitris Tsintikidis
Rok vydání: 2010
Předmět:
Zdroj: Free-Space Laser Communications X.
ISSN: 0277-786X
DOI: 10.1117/12.859917
Popis: We present some preliminary results from our recent free-space optical communications field test experiments in the foggy littoral environment along the coast of Point Loma, San Diego, conducted between October 2009 and June 2010. Our custom-built 850nm lasercomm system uses on-off keyed non-return-to-zero intensity-modulation and direct-detection to transmit pseudo-random bit sequences (PN-11 codes) at 250 Mbps over a 300m horizontal atmospheric path. We investigate improvements offered by using the latest Advanced Navy Aerosol Model to calculate the aerosol size-distribution function, a fundamental input to the radiative transfer code which we use to generate an estimate of the channel frequency response/impulse-response function. The estimated channel response function is used to design an equalization filter to correct signal distortion due to multiple-scattering effects and additive noise. We compare the performance of the Advanced Navy Aerosol Model against the more simplistic log-normal, Gaussian, and Mooradian Pt. Loma distributions. In this conference proceeding manuscript we are presenting only preliminary findings of our work in progress. Additional analysis, verification, and study is required before any final results can be posited from these preliminary findings.
Databáze: OpenAIRE