Browsing by Author "Kalyanpur, M.N."

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    Classification of FSO channel models using radial basis function neural networks and their ber performance with Luby transform codes
    (2012) Prakash, G.; Kulkarni, M.; Sripati Acharya, U.; Kalyanpur, M.N.
    Free Space Optical (FSO) communication systems offer a license free and cost effective access performance. FSO links can suffer from data packet corruption and erasure. Error control codes can help to mitigate turbulence induced fading and can improve the error performance of such links. Various statistical models have been proposed to describe the atmospheric turbulence channels. The choice of the appropriate model for varying level of turbulence is dependent on the atmospheric parameters. In this paper we classify the channels using Radial Basis Function Neural Networks to decide the best fit. We then investigate the error performance of FSO channels modeled as Gamma- Gamma and K distribution functions with Luby Transform encoding which are rateless codes. Simulation results are used to compare the performance of different modulation schemes with Luby Transform encoding and also to classify the appropriate distribution function for the channel model. © 2012 by IJAI (CESER Publications).
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    Performance analysis of Free Space Optical links encoded using Luby Transform codes
    (2012) Prakash, G.; Kulkarni, M.; Shripathi, Acharya U.; Kalyanpur, M.N.
    Free Space Optical (FSO) communication is an emerging transmission technique to transmit high data rates without using cables. This technology is expected to revolutionize the present communication system architectures both in the terrestrial and the in -space architecture. Atmospheric effects can significantly degrade the performance of FSO systems. This reduces the SNR and leads to impaired performance. FSO channels can be modeled using Gamma-Gamma, Weibull, Log-Normal, K distribution functions. Error control codes can help to mitigate atmospheric turbulence induced signal fading in free space optical communication links. Luby Transform codes belong to a class of error control codes called Fountain codes and are meant for erasure channels. In this paper, we propose encoding FSO links with Luby Transform (LT) codes for error channels. Decoding is done using belief propagation with Log Likelihood Ratio and results are obtained for different modulation schemes under different channel distributions. � 2012 IEEE.
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    Performance analysis of Free Space Optical links encoded using Luby Transform codes
    (2012) Prakash, G.; Kulkarni, M.; Sripati, U.; Kalyanpur, M.N.
    Free Space Optical (FSO) communication is an emerging transmission technique to transmit high data rates without using cables. This technology is expected to revolutionize the present communication system architectures both in the terrestrial and the in -space architecture. Atmospheric effects can significantly degrade the performance of FSO systems. This reduces the SNR and leads to impaired performance. FSO channels can be modeled using Gamma-Gamma, Weibull, Log-Normal, K distribution functions. Error control codes can help to mitigate atmospheric turbulence induced signal fading in free space optical communication links. Luby Transform codes belong to a class of error control codes called Fountain codes and are meant for erasure channels. In this paper, we propose encoding FSO links with Luby Transform (LT) codes for error channels. Decoding is done using belief propagation with Log Likelihood Ratio and results are obtained for different modulation schemes under different channel distributions. © 2012 IEEE.