Bit-Wise Unequal Error Protection for Variable-Length Block Codes With Feedback

• Published in: IEEE transactions on information theory 2013-03, Vol.59 (3), p.1475-1504
• Main Authors: Nakiboglu, B., Gorantla, S. K., Lizhong Zheng, Coleman, T. P.
• Format: Article
• Language: English
• Subjects: Applied sciences; Block codes; Burnashev's exponent; Coding theory; Coding, codes; Decoding; discrete memoryless channels (DMCs); Error correction & detection; Error correction codes; error exponents; Error probability; errors- and-erasures decoding variable-length block coding; Exact sciences and technology; feedback; Feedback control systems; Information theory; Information, signal and communications theory; Kudryashov's signaling; Markov processes; Random variables; Signal and communications theory; Switching and signalling; Systems, networks and services of telecommunications; Telecommunications; Telecommunications and information theory; unequal error protection (UEP); variable-length communication; Vectors; Yamamoto-Itoh scheme
• ISSN: 0018-9448; 1557-9654
• DOI: 10.1109/TIT.2012.2227671

The bit-wise unequal error protection problem, for the case when the number of groups of bits l is fixed, is considered for variable-length block codes with feedback. An encoding scheme based on fixed-length block codes with erasures is used to establish inner bounds to the achievable performance for finite expected decoding time. A new technique for bounding the performance of variable-length block codes is used to establish outer bounds to the performance for a given expected decoding time. The inner and the outer bounds match one another asymptotically and characterize the achievable region of rate-exponent vectors, completely. The single-message message-wise unequal error protection problem for variable-length block codes with feedback is also solved as a necessary step on the way.