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

Download
2015
Bülbüldere, Mehmet
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.

Suggestions

An Investigation on belief propagation decoding of polar codes
Doğan, Orkun; Diker Yücel, Melek; Department of Electrical and Electronics Engineering (2015)
Polar codes are provably symmetric capacity achieving codes for any given binary input discrete memoryless channel, with low encoding and decoding complexities. Polar codes introduced by Erdal Arıkan in 2009 are based on the channel polarization. N binary channels are synthesized out of N copies of binary input discrete memoryless channels, such that as N goes to infinity each of the synthesized channel’s capacity goes to either 0 or 1; i.e., the channels are seen purely as noisy or noiseless channels. Thes...
Efficient and Accurate Electromagnetic Optimizations Based on Approximate Forms of the Multilevel Fast Multipole Algorithm
Onol, Can; Karaosmanoglu, Bariscan; Ergül, Özgür Salih (2016-01-01)
We present electromagnetic optimizations by heuristic algorithms supported by approximate forms of the multilevel fast multipole algorithm (MLFMA). Optimizations of complex structures, such as antennas, are performed by considering each trial as an electromagnetic problem that can be analyzed via MLFMA and its approximate forms. A dynamic accuracy control is utilized in order to increase the efficiency of optimizations. Specifically, in the proposed scheme, the accuracy is used as a parameter of the optimiz...
A Combinatorial Methodology for Optimizing Non-Binary Graph-Based Codes: Theoretical Analysis and Applications in Data Storage
Hareedy, Ahmed; Lanka, Chinmayi; Guo, Nian; Dolecek, Lara (2019-04-01)
© 2018 IEEE.Non-binary (NB) low-density parity-check (LDPC) codes are graph-based codes that are increasingly being considered as a powerful error correction tool for modern dense storage devices. Optimizing NB-LDPC codes to overcome their error floor is one of the main code design challenges facing storage engineers upon deploying such codes in practice. Furthermore, the increasing levels of asymmetry incorporated by the channels underlying modern dense storage systems, e.g., multi-level Flash systems, exa...
Dense depth map estimation for multiple view coding
Ozkalayci, Burak; Alatan, Abdullah Aydın (2006-01-01)
In this paper the basics of a proposed method that handles the stereo and especially multiple view coding problem in a geometrical way, are explained. For this purpose, estimation of the depth maps of the multiple views, captured by fully calibrated cameras, are done. In depth map estimation problem Markov Random Field modelling is used to have a depth map in a desired smoothness and in an efficient coding fashion. The geometric structure which is acquired by the depth map estimation, is used to reconstruct...
Finite-length construction of high performance spatially-coupled codes via optimized partitioning and lifting
Esfahanizadeh, Homa; Hareedy, Ahmed; Dolecek, Lara (2019-01-01)
© 1972-2012 IEEE.Spatially-coupled (SC) codes are a family of graph-based codes that have attracted significant attention, thanks to their capacity approaching performance and low decoding latency. An SC code is constructed by partitioning an underlying block code into a number of components and coupling their copies together. In this paper, we first introduce a general approach for the enumeration of detrimental combinatorial objects in the graph of finite-length SC codes. Our approach is general in the se...
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.