Energy efficient rateless codes for high speed data transfer over free space optical channels

Geetha Prakash; Muralidhar Kulkarni; U. Sripati Acharya

doi:10.1117/12.2077961

16 March 2015 Energy efficient rateless codes for high speed data transfer over free space optical channels

Geetha Prakash, Muralidhar Kulkarni, U. Sripati Acharya

Proceedings Volume 9354, Free-Space Laser Communication and Atmospheric Propagation XXVII; 93540C (2015) https://doi.org/10.1117/12.2077961
Event: SPIE LASE, 2015, San Francisco, California, United States

Abstract

Terrestrial Free Space Optical (FSO) links transmit information by using the atmosphere (free space) as a medium. In this paper, we have investigated the use of Luby Transform (LT) codes as a means to mitigate the effects of data corruption induced by imperfect channel which usually takes the form of lost or corrupted packets. LT codes, which are a class of Fountain codes, can be used independent of the channel rate and as many code words as required can be generated to recover all the message bits irrespective of the channel performance. Achieving error free high data rates with limited energy resources is possible with FSO systems if error correction codes with minimal overheads on the power can be used. We also employ a combination of Binary Phase Shift Keying (BPSK) with provision for modification of threshold and optimized LT codes with belief propagation for decoding. These techniques provide additional protection even under strong turbulence regimes. Automatic Repeat Request (ARQ) is another method of improving link reliability. Performance of ARQ is limited by the number of retransmissions and the corresponding time delay. We prove through theoretical computations and simulations that LT codes consume less energy per bit. We validate the feasibility of using energy efficient LT codes over ARQ for FSO links to be used in optical wireless sensor networks within the eye safety limits.

Citation Download Citation

Geetha Prakash, Muralidhar Kulkarni, and U. Sripati Acharya "Energy efficient rateless codes for high speed data transfer over free space optical channels", Proc. SPIE 9354, Free-Space Laser Communication and Atmospheric Propagation XXVII, 93540C (16 March 2015); https://doi.org/10.1117/12.2077961

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available

Members: $17.00

Non-members: $21.00 ADD TO CART

PROCEEDINGS
15 PAGES

DOWNLOAD PAPER SAVE TO MY LIBRARY

GET CITATION

RIGHTS & PERMISSIONS

Get copyright permission Get copyright permission on Copyright Marketplace

KEYWORDS

Free space optics

Turbulence

Automatic repeat request

Atmospheric propagation

Atmospheric optics

Free space

Receivers

Show All Keywords

Keywords/Phrases

Search In:

Publication Years