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We investigate the structure of quantizer rules at the local sensors in distributed detection networks, in the presence of eavesdroppers (Eve), under asymptotic regime (number of sensors tending to infinity) for binary hypotheses. These local quantizers are designed in such a way that the confidentiality of sensor data is preserved while achieving optimal detection performance at the fusion center...
Tree-based Gibbs sampling (proposed by Hamze and de Freitas) is used to compute a Monte-Carlo estimate of the partition function of factor graphs with cycles. The proposed method can be used, in particular, to compute the capacity of noiseless constrained 2-D channels.
We examine the extent to which Gaussian relay networks can be approximated by deterministic networks, and present two results, one negative and one positive. The gap between the capacities of a Gaussian relay network and a corresponding linear deterministic network can be unbounded. The key reasons are that the linear deterministic model fails to capture the phase of received signals, and there is...
We consider a Gaussian multiple-access relay channel with multiple sources, a relay and a destination. We assume that the received signals at the relay and the destination from different nodes are orthogonal. Additionally, we assume that the relay performs an instantaneous mapping to compress all received signals from different sources into one output symbol. We refer to this as analog network coding...
Recently, there has been a lot of interest in the connections between information-theoretic and estimation-theoretic properties of various noisy channel models. For example, Guo, Shamai, and Verdu?? have shown that mutual information in Gaussian channels is related in a simple way to minimum mean-square error, regardless of the input distribution. In this paper, we consider the class of E-type channels,...
A (layered) broadcast approach is studied for fading wiretap channels. The basic idea is to employ superposition coding to encode information into a number of layers and use stochastic encoding for each layer to keep the corresponding information secret from an eavesdropper. The legitimate receiver successively decodes information one layer after another by canceling the interference caused by the...
A novel sum-rate outer bound for the Gaussian interference channel with a relay is presented. The outer bound is obtained by adapting the genie-aided approach developed for interference channels in. The cut-set bound for this channel is also derived and is shown to be much looser than the new bound. The new bound is also compared to an achievable rate region we introduced in previous work. We show...
The throughput of a linear cellular uplink with a random number of users, different power control schemes, and cooperative base stations is considered in the large system limit where the number of cells is large for non fading Gaussian channels. The analysis is facilitated by establishing an analogy between the cellular channel per-cell throughput with joint multi-cell processing (MCP), and the rate...
A hard-deadline, opportunistic scheduling problem in which B bits must be transmitted within T time-slots over a time-varying channel is studied: the transmitter must decide how many bits to serve in each slot based on knowledge of the current channel but without knowledge of the channel in future slots, with the objective of minimizing expected transmission energy. In order to focus on the effects...
This paper presents an achievable rate region for a 2-user Gaussian Z-interference channel with a noiseless and bidirectional digital communication link between the receivers. The region is achieved by utilizing the rate-splitting encoding technique, and the decode-and-forward and compress-and-forward strategies. In the very strong interference regime, the capacity region is achieved. In the weak...
We consider the wireless relay network model as introduced by Avestimehr, Diggavi and Tse for approximating Gaussian relay channels and show that it is a special case of a more abstract flow model that we introduce in this paper. This flow model is based on linking systems, a combinatorial structure with a tight connection to matroids. A main advantage of this flow model is that properties and algorithms...
We study a multi-source Gaussian relay network consisting of K source-destination pairs having K unicast sessions. We assume M layers of relays between the sources and the destinations. We find achievable degrees of freedom of the network. Our schemes are based on interference alignment at the transmitters and symbol extension and opportunistic interference cancellation at the relays. For K-L-K networks,...
It has been conjectured that complex Gaussian interference channels with constant channel coefficients have only one degree-of-freedom (DoF) regardless of the number of users. While several examples are known of constant channels that achieve more than 1 DoF, these special cases only span a subset of measure zero. In other words, for almost all channel coefficient values, it is not known if more than...
We study two-way communications over a three-node Gaussian relay channel. Several practical relaying strategies are considered, including bitwise XOR-based decode-and-forward (DF), superposition-based DF, and amplify-and-forward (AF). For each considered two-way relay scheme, we show that its achievable rate pair is governed by a set of linear inequalities. As a result, we obtain explicit, analytical...
By interpolating between communication theory and synergetics, we provide a bridge to connect the two kinds of subjects. As applications, the capacity formula of multiple input and multiple output (MIMO) Gaussian channels is derived by using the Fokker-Planck Equation of the synergetics, it is in accordance with the Telatar's capacity and gives a physical explanation of the observed channel characteristics...
Decision fusion rules for wireless sensor networks in fading channel are investigated in this paper. Optimal Likelihood ratio rule has been presented under the assumption of single-sideband Gaussian channel model. However, acquiring channel information may be too costly for resource constrained sensor networks. Suboptimal likelihood ratio fusion rule is proposed which requires only the knowledge of...
We consider the fading broadcast channel from a secrecy point of view. In this channel, each user views the other user as an eavesdropper, and wants to keep its information as secret from the other user as possible. First, we consider a more general channel model which consists of L independent sub-channels, where in each sub-channel, one of the users' channel is less noisy with respect to the other...
We investigate the Gaussian, three-nodes relay channel with orthogonal receive components, i.e., the transmitted signals from the source and the relay do not interfere with each other. We develop and analyze low-complexity symbol-wise (as opposed to block-wise) relaying strategies based on a one-dimensional, parametric piecewiselinear (PL) mapping. We numerically compute and optimize the achievable...
We consider a Gaussian relay channel, with the source and relay operating in different frequency bands. Hence, the received signals at the destination are orthogonal. We also assume that the source reuses the frequency band in which the relay is operating, to communicate with another destination. This results in a scenario that can be modeled in such a way that the relay-destination link suffers from...
A random coding theorem for nonlinear additive Gaussian channels is presented. Modeling the channel's nonlinear behavior as a causal, stationary Volterra system and under maximum likelihood decoding, an upper bound on the average error probability is obtained. The proposed bound is deduced by deploying exponential martingale inequalities. Cubic nonlinearities are used as example to illustrate the...
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