Design of LT Codes with Equal and Unequal Erasure Protection over Binary Erasure Channels

• Published in: IEEE communications letters Vol. 17; no. 2; pp. 261 - 264
• Main Authors: Hussain, I., Ming Xiao, Rasmussen, L. K.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01-02-2013; Institute of Electrical and Electronics Engineers
• Subjects: Applied sciences; Coding, codes; Decoding; Encoding; erasure channels; erasure floor; Error correction codes; Exact sciences and technology; Generators; Information, signal and communications theory; Iterative decoding; LT codes; Signal and communications theory; Table lookup; Telecommunications and information theory; Transforms; unequal erasure protection; Performance evaluation; Fountain code; Binary channel; Coding; erasure floor; Asymptotic behavior; LT codes; Error correcting code; erasure channels; unequal erasure protection
• ISSN: 1089-7798; 1558-2558; 1558-2558
• DOI: 10.1109/LCOMM.2013.011113.122283

The erasure floor performance of Luby Transform (LT) codes is mainly determined by the minimum variable-node degree. Thus we propose a modified encoding scheme that maximizes the minimum variable-node degree for transmission over binary erasure channels. The proposed scheme leads to an almost-regular variable-node degree distribution. The encoding process is generalized to accommodate arbitrary variable-node degree distributions for additional improved performance. The asymptotic performance is investigated using density evolution and compared with a conventional LT code. The scheme is further extended to enable a higher level of unequal erasure protection.