Vinod M. Prabhakaran

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In this correspondence, we consider the problem of constructing an erasure code for storage over a network when the data sources are distributed. Specifically, we assume that there are <i>n</i> storage nodes with limited memory and <i>k</i> &lt; <i>n</i> sources generating the data. We want a data collector, who can appear anywhere in the network, to query(More)
When it is desired to transmit redundant data over an insecure and bandwidth-constrained channel, it is customary to first compress the data and then encrypt it. In this paper, we investigate the novelty of reversing the order of these steps, i.e., first encrypting and then compressing, without compromising either the compression efficiency or the(More)
In this paper, the role of cooperation in managing interference-a fundamental feature of the wireless channel-is investigated by studying the two-user Gaussian interference channel where the source nodes can both transmit and receive in full duplex. The sum capacity of this channel is obtained within a gap of a constant number of bits. The coding scheme(More)
Consider a large-scale wireless sensor network of <i>n</i> nodes, where a fraction <i>k</i> out of <i>n</i> generate data packets of global interest. Assuming that the individual nodes have limited storage and computational capabilities, we address the problem of how to enable ubiquitous access to the distributed data packets.Specifically, we assume that(More)
We investigate the problem of constructing fountain codes for distributed storage in sensor networks. Specifically, we assume that there are n storage nodes with limited memory and k &lt; n data nodes generating the data by sensing the environment. We want a data collector who can appear anywhere in the network, to query any k + epsi storage nodes and be(More)
The compound wiretap channel provides a general framework for studying secrecy communication under channel uncertainty. Characterizing the secrecy capacity of nondegraded compound wiretap channels is a challenging problem in information theory. This paper considers the class of parallel Gaussian compound wiretap channels with only one possible channel(More)
This paper presents an information-theoretic study of video codecs that are based on the principle of source coding with side information at the decoder In contrast to the classical wner-Ziv side-infomation source coding pmblem [I], in this work we address the situation where the source and side-information are connected thmugh a state of nature that is(More)
Interference is a fundamental feature of the wireless channel. To better understand the role of cooperation in interference management, the two-user Gaussian interference channel where the destination nodes can cooperate by virtue of being able to both transmit and receive is studied. The sum capacity of this channel is characterized up to a constant number(More)
The problem of broadcasting a parallel Gaussian source over an additive white Gaussian noise broadcast channel under the mean-squared error distortion criterion is studied. A hybrid digital-analog coding strategy which combines source coding with side information, channel coding with side information, layered source coding, and superposition broadcast(More)