An A-Based Algorithm for Constructing Reversible Variable Length Codes with Minimum Average Codeword Length

• Published in: IEEE transactions on communications Vol. 58; no. 11; pp. 3175 - 3185
• Main Authors: Yuh-Ming Huang, Ting-Yi Wu, Han, Yunghsiang S
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.11.2010; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: A algorithm; Algorithms; Applied sciences; Asymmetry; Binary trees; Coding, codes; Compressing; Construction; Construction industry; Encoding; Errors; Exact sciences and technology; Information, signal and communications theory; Optimization; reversible variable length codes; Search problems; Signal and communications theory; Source coding; Synchronization; Systems, networks and services of telecommunications; Telecommunications; Telecommunications and information theory; Transform coding; Transmission and modulation (techniques and equipments); Upper bound; Performance evaluation; A algorithm; reversible variable length codes; Source coding; Data transmission; Transmission loss; Growth of error; Synchronization; Algorithm; Variable length code
• ISSN: 0090-6778; 1558-0857
• DOI: 10.1109/TCOMM.2010.091710.0901872

Variable length codes (VLCs) are widely adopted in many compression standards due to their good coding efficiency on average codeword length. However, an inherent problem with a VLC is that an error of even one bit can cause serious error propagation and thus loss of synchronization at the receiver, which would lead to a series of non-correctly decoded symbols. Reversible variable length codes (RVLCs) were introduced to significantly mitigate this phenomenon. In this work, a method to find an optimal RVLC in terms of the minimum average codeword length is first formulated as a tree-searching problem, and then, instead of performing an exhaustive search, an A*-based construction algorithm is proposed to find an optimal RVLC. The proposed algorithm has been applied to several benchmarks for sources and has found respective optimal symmetric and asymmetric RVLCs.