Polar-code construction and decoding techniquesPolar-code construction and decoding techniquesΤεχνικές κατασκευής και αποκωδικοποίησης πολικών κωδίκων
Διπλωματική Εργασία
Diploma Work
2018-02-222018enPolar codes, recently invented by Arikan, are the first provably capacity achieving codes for any binary input symmetric discrete memoryless channel
with low encoding and decoding complexity. This thesis explores the practical
implementation of polar codes which are complexity efficient and perform
well for binary erasure channel (BEC) and binary symmetric channel (BSC).
The explicit code construction is based on a characteristic called channel polarization which involves generating N extremal (perfect or completely noisy)
channels from N independent uses of the same base channel. Information
bits are sent over the noiseless channels while pilot bits, called frozen bits,
are assigned to the noisy ones. Code design for BEC is based on the recursive
relations presented in the original paper whereas for BSC we propose a
heuristic and efficient algorithm and compare it to the method of recursive
estimation of Bhattacharyya parameters of bit-channels. The encoding is implemented using a recursive butterfly structure with O(N logN) complexity,
where N is the block length of the code. Two main low complexity decoders
are compared in terms of bit error rate: successive cancellation decoder proposed by Arikan having complexity O(N logN) with susceptibility to error
propagation and mediocre bit error rate performance at small or moderate
code lengths and list decoder, proposed by Tal and Vardy, with complexity
O(LN logN) where L is the list size.http://creativecommons.org/licenses/by/4.0/Πολυτεχνείο Κρήτης::Σχολή Ηλεκτρολόγων Μηχανικών και Μηχανικών ΥπολογιστώνAmiridi_Magda_Dip_2018.pdfChania [Greece]Library of TUC2018-02-22application/pdf1.2 MBfree
Amiridi Magda
Αμιριδη Μαγδα
Karystinos Georgios
Καρυστινος Γεωργιος
Bletsas Aggelos
Μπλετσας Αγγελος
Liavas Athanasios
Λιαβας Αθανασιος
Πολυτεχνείο Κρήτης
Technical University of Crete
Information theory