Abstract:

Talk 1 (Weds)

Multiterminal video coding

Multiterminal (MT) source coding considers the problem of separate encoding and joint decoding of multiple correlated sources under distortion constraints. One can loosely view it as the lossy version of Slepian-Wolf coding. MT source coding is also more general than Wyner-Ziv coding. It has gained research interest lately due to potential applications in sensor networks and distributed video coding.

Inspired by recent works on the sum rate of quadratic Gaussian MT source coding and limit-approaching code designs, this talk examines MT source coding of correlated video sequences to save the sum rate over independent coding. The first video sequence is coded by H.264/AVC, while the remaining sequences are compressed sequentially using Wyner-Ziv coding with side information generated from the already decoded sequences. To improve the performance of Wyner-Ziv coding, a depth-map-based view interpolation approach and a novel soft-decision side information generation method are proposed. Experiments with two- and three-terminal videos show that our scheme achieves a lower sum-rate than separate H.264/AVC coding. Comparison with JMVM joint encoding is also provided.

Talk 2 (Thursday)

Cooperation in the low power regime for the MAC using multiplexed rateless codes

We consider cooperation in the low power/SNR regime for the multiple access channel (MAC) with the assumption that the transmitters have no channel state information. A relevant performance measure to consider is therefore the outage capacity. We develop cooperation methods based on multiplexed coding in conjunction with rateless codes and find the achievable rates and in particular the minimum energy per bit required to achieve a certain outage probability. We also derive methods to find the wideband slope for the outage rate. We consider two modes of

operation: full duplex (code division multiplexing, CDM), where nodes can transmit and receive simultaneously on the same frequency, and half duplex (frequency division multiplexing or FDM), where the nodes transmit and listen on different frequency bands. We show that, perhaps surprisingly, there is little loss in performance when using FDM. Furthermore, our results show that multiplexed rateless codes come within 0.1 dB of the outer bound on capacity. We also develop practical rateless coding methods for FDM using multiplexed Raptor codes which operate within 0.52 and 1.1 dB of the theoretical limit for the two- and four-user case, respectively.

Joint work with Prof. Anders Host-Madsen at the U. of Hawaii

Biography：

Zixiang Xiong received the Ph.D. degree in Electrical Engineering in 1996 from the  University of Illinois at Urbana-Champaign. From 1995 to 1997, he was with  Princeton University, first as a visiting student, then as a research associate. From 1997 to 1999, he was with the  University of Hawaii. Since 1999, he has been with the Department of Electrical and Computer Engineering at Texas A&M University, where he is a professor. He received an NSF Career Award in 1999, an ARO Young Investigator Award in 2000 and an ONR Young Investigator Award in 2001. He also received the

2006 IEEE Signal Processing Magazine best paper award. He served as associate editor for the IEEE Trans. on Circuits and Systems for Video Technology (1999-2005), the IEEE Trans. on Image Processing (2002-2005), the  IEEE Trans. on Signal Processing (2002-2006), and the  IEEE Trans. on Systems, Man, and Cybernetics (part B) (2005-2009). He is currently an associate editor for the IEEE Trans. on Communications. He is a fellow of the IEEE.