Onkar Dabeer

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As communication systems scale up in speed and bandwidth, the cost and power consumption of high-precision (e.g., 8-12 bits) analog-to-digital conversion (ADC) becomes the limiting factor in modern transceiver architectures based on digital signal processing. In this work, we explore the impact of lowering the precision of the ADC on the performance of the(More)
In this paper, we apply the theory of hypothesis testing to the steganalysis, or detection of hidden data, in the least significant bit (LSB) of a host image. The hiding rate (if data is hidden) and host probability mass function (PMF) are unknown. Our main results are as follows. a) Two types of tests are derived: a universal (over choices of host PMF)(More)
As communication systems scale up in speed and bandwidth, the power consumption and cost of high-precision (e.g., 6-12 bits) analog-to-digital conversion (ADC) becomes the limiting factor in modern receiver architectures based on digital signal processing. In this paper, we consider the effects of lowering the precision of the ADC on the performance of the(More)
In this paper, we analyze a collaborative filter that answers the simple question: What is popular amongst your “friends”? While this basic principle seems to be prevalent in many practical implementations, there does not appear to be much theoretical analysis of its performance. In this paper, we partly fill this gap. While recent works on(More)
Motivated by the estimation of spatio-temporal events with cheap, simple sensors, we consider the problem of estimation of a parameter thetas of a signal s(x;thetas) corrupted by noise assuming that only 1-bit precision dithered quantized samples are available. An estimate that does not require the knowledge of the dither signal and the noise distribution(More)
For the least mean square (LMS) algorithm, we analyze the correlation matrix of the filter coefficient estimation error and the signal estimation error in the transient phase as well as in steady state. We establish the convergence of the second-order statistics as the number of iterations increases, and we derive the exact asymptotic expressions for the(More)
Weber's law suggests a logarithmic relationship between perceptual stimuli and human perception. The Weber sampler is an adaptive, nonuniform sampling mechanism that exploits Weber's law to sample the signal at a minimum rate without significant perceptual degradation. In this paper, we introduce and analyze a regularized Weber sampler for smooth(More)
In this paper we consider a hypothesis testing approach for detection of hiding in the least significant bit (LSB). This steganalysis problem is a composite hypothesis testing problem. We state a regularity condition on the image histogram, which reduces this problem to a simple hypothesis testing problem. We then develop a number of simple practical tests(More)
Modern communication receiver architectures center around digital signal processing (DSP), with the bulk of the receiver processing being performed on digital signals obtained after analog-to-digital conversion (ADC). In this paper, we explore Shannon-theoretic performance limits when ADC precision is drastically reduced, from typical values of 8-12 bits(More)