Two Extended Programmable BCH Soft Decoders Using Least Reliable Bits Reprocessing

• Published in: Circuits, systems, and signal processing Vol. 33; no. 5; pp. 1369 - 1391
• Main Authors: Osman, Mohamed T. A., Fahmy, Hossam A. H., Fahmy, Yasmine A. H., Elsabrouty, Maha M., Shalash, Ahmed
• Format: Journal Article
• Language: English
• Published: Boston Springer US 01-05-2014; Springer Nature B.V
• Subjects: Algebra; Circuits; Circuits and Systems; Decoders; Decoding; Electrical Engineering; Electronics and Microelectronics; Engineering; Gain; Instrumentation; Linear codes; Maximum likelihood decoding; Maximum likelihood method; Programmable logic controllers; Reduction; Reprocessing; Signal,Image and Speech Processing; BCH codes; Programmable architecture; VLSI; Soft decoding; Maximum likelihood decoding
• ISSN: 0278-081X; 1531-5878
• DOI: 10.1007/s00034-013-9709-x

This paper proposes two Bose–Chaudhuri–Hocquenghem (BCH) soft decoders suitable for high-rate codes with medium to large word length. The proposed decoders extend the correcting capability by providing a programmable performance gain according to the choice of the extra compensated bits
p
, with a theoretical maximum likelihood decoding when 2
t
+
p
approaches the codeword size
n
, where
t
is the correcting capability of the code under algebraic decoding. Our proposed architectures for the proposed algorithms use pipelined arithmetic units, leading to a reduction in the critical paths. This allows for an increase in the operating frequency by up to
m
/2 times compared to algebraic decoders, where
m
is the Galois field size. Our proposed decoders operate only on the least reliable bits, which leads to a reduction in the decoder complexity by removing the Chien search procedure.