Graduate Exam Abstract

Zheng Wang

Ph.D. Final
May 18, 2011, 10am-12pm
ECE Conference Room
Channel Coding for Network Communication: An Information Theoretic Perspective

Abstract: Channel coding helps a communication system to combat noise and interference by adding ``redundancy'' to the source message. Theoretical fundamentals of channel coding in point-to-point systems have been intensively studied in the field of information theory, which was proposed by Claude Shannon in his celebrated work in 1948. A set of landmark results haven been developed to characterize the performance limitations in terms of the rate and reliability tradeoff bounds. However, unlike its success in point-to-point systems, information theory has not yielded as rich results in network communication, which has been a key a research focus over the past two decades. Due to the limitations posed by some of the key assumptions in classical information theory, network information theory is far from being mature and complete. For example, classical information theoretic model assumes that communication parameters such as the information rate should be jointly determined by all transmitters and receivers. Communication should be carried out continuously over a long time duration such that the overhead of communication coordination becomes negligible. Communication channel should be stationary in order for the coding scheme to transform the randomness in channel noise into deterministic statistics. These assumptions, although reasonable in a point-to- point system, do not permit an extensive application of channel coding in network systems because they essentially ignored the dynamic nature of network communication. Network systems deal with bursty message transmissions between highly dynamic users. For various reasons, joint determination of key communication parameters before message transmission is often infeasible or expensive. Communication channels can often be non-stationary due to unexpected interference. The objective of this work is to extend information theory toward network communications scenarios. We develop new channel coding results, in terms of the communication rate and error performance tradeoff, for several non-classical communication models, in which key assumptions made in classical channel coding do not hold.

Adviser: J. Rockey Luo
Co-Adviser: N/A
Non-ECE Member: Anton Betten, Department of Mathematics
Member 3: Louis L. Scharf, Electrical & Computer Engineering
Addional Members: Edwin K. Chong, Electrical & Computer Engineering

Journal Papers: 1. Z. Wang, J. Luo, "Approaching Blokh-Zyablov Error Exponent with Linear-Time Encodable/Decodable Codes," IEEE Communications Letters, Vol. 13, No. 6, pp. 438-440, June 2009. 2. Z. Wang, J. Luo, "Fountain Communication using Concatenated Codes," submitted to IEEE Trans. on Information Theory. 3. Z. Wang, J. Luo, "Error Performance of Channel Coding in Random Access Communication," submitted to IEEE Trans. on Information Theory. 4. Z. Wang, J. Luo, "Channel Coding for Random Multiple Access Communication," to be submitted to IEEE Trans. on Information Theory. Conference Papers: 1. Z. Wang, J. Luo, "Coding Theorems for Random Access Communication over Compound Channel," IEEE International Symposium on Information Theory, Saint Petersburg, Russia, July 2011. 2. Z. Wang, J. Luo, "Achievable Error Exponent of Channel Coding in Random Access Communication," IEEE International Symposium on Information Theory, Austin, TX, June 2010. 3. Z. Wang, J. Luo, "Concatenated Fountain Codes," IEEE International Symposium on Information Theory, Seoul, Korea, June 2009.

Program of Study: