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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 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)
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)
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)
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)
We introduce the two user finite state compound Gaussian interference channel and characterize its capacity region to within one bit. The main contributions involve both novel inner and outer bounds. The inner bound is multilevel superposition coding but the decoding of the levels is opportunistic, depending on the channel state. The genie aided outer bound(More)
The performance gain by allowing half-duplex source cooperation is studied for Gaussian interference channels. The source cooperation is in-band, meaning that each source can listen to the other source's transmission, but there is no independent (or orthogonal) channel between the sources. The half-duplex constraint supposes that at each time instant the(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)