An Analysis on Luby transform encoding-decoding algorithms and proposals for more efficient practical usage /

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2015

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Bülbüldere, Mehmet

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We study the encoding and decoding algorithms of Luby Transform Codes and analyze the performance of these codes. Luby Transform Coding technique is one of the classes of rateless codes. Depending on the use scenario, higher data rates can be obtained by using LT codes instead of using only conventional fixed rate codes. Segmentation of data to be transmitted and channel conditions have major effects on the speed of transmission of whole data. Throughput, data rate, decoding success ratio results, which are obtained through the LT code simulator and conventional fixed rate code simulator constructed in MATLAB during this thesis work, are analyzed according to the several factors such as signal to noise ratio (SNR) of received signals, symbol length, number of input symbols, packet erasure probability for both cases with and without LT codes. In addition, different distributions of encoding symbol degrees are studied for LT codes since degree distribution is another significant factor affecting the obtained throughput. The cases with and without LT codes are compared to each other for both point-to-point and point-to-multipoint transmission cases. Furthermore, effect of using error correction codes is analyzed for different received SNR values. Since their structures are open to be modified flexibly, the simulator constructed for this thesis can be used for numerous different practical scenarios while deciding on the optimum parameters to obtain aimed decoding success ratios, data rates and throughputs.

Subject Keywords

Data transmission systems., Digital communications., Coding theory., Algorithms.

URI

http://etd.lib.metu.edu.tr/upload/12618417/index.pdf
https://hdl.handle.net/11511/24369

Collections

Graduate School of Natural and Applied Sciences, Thesis

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Citation Formats

M. Bülbüldere, “An Analysis on Luby transform encoding-decoding algorithms and proposals for more efficient practical usage /,” M.S. - Master of Science, Middle East Technical University, 2015.