•   When: Tuesday, December 16, 2014 09:00 AM
•   Speakers: Wook Jung
•   Location: ENGR 4801
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Abstract

Traditional network protocols employ error control techniques for reliable information dissemination over noisy communication channels. In this dissertation, two main topics are investigated for e cient error controls over a broadcast channel. First, unequal error protection (UEP) coding schemes for multiuser communications are investigated, and we propose integer programming approaches to UEP coding and decoding. Second, reliable packet transmissions over a single-hop broadcast network are considered, and we propose a unied solution to use a deterministic network coding for a packet retransmission scheme and a packet-level forward error correction scheme.

For multiuser communications over a broadcast channel, integer programming approaches are introduced to the construction and the decoding of a binary linear UEP code. First, optimal UEP codes are constructed from integer programming for maximum e ciency, and lower bounds of UEP codes are derived to show the e ciency. Then, performance of the UEP coding scheme for multiuser communications are analyzed on a degraded broadcast channel. Finally, a decoding method of the binary UEP code, that uses iterative integer programming and majority logic, is proposed. By presenting numerical results, examples, and comparisons, we demonstrate that the UEP coding scheme e ectively provides e cient forward error correction for multiuser broadcast communications.

For reliable packet transmissions over a single-hop broadcast network, we propose packet-level error control schemes by using a deterministic linear network coding. We rst construct a deterministic network code based on a Reed-Solomon (RS) error correcting code. Then, we provide an adaptive way to apply the deterministic network code for both retransmissions and forward error corrections by puncturing a generator matrix of the RS code. Numerical analysis and simulations are performed to show the e ciency of the error control schemes.