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Content-based image retrieval (CBIR) has the potential to provide medical doctors with a powerful resource to help make accurate diagnosis. The main goal of CBIR is to efficiently retrieve images that are visually similar to a query image. In this paper we focus on CBIR from chest x-ray image databases. We describe a novel approach for extraction of region of interest (ROI), which is a bounding box...
The problem of the detection of a signal in the presence of broad-band noise and interferences that lie in a subspace that is imperfectly known is considered. It is assumed that a basis (or generating set) of the interference subspace is known up to additive white Gaussian noise. This amounts to assuming that each of these basis vectors lies in a cone, the aperture of which depends upon the level...
The recently-proposed theory of distilled sensing establishes that adaptivity in sampling can dramatically improve the performance of sparse recovery in noisy settings. In particular, it is now known that adaptive point sampling enables the detection and/or support recovery of sparse signals that are otherwise too weak to be recovered using any method based on non-adaptive point sampling. In this...
This paper investigates simple user selection strategies in a multiuser downlink system with a single transmitter, multiple legitimate receivers, and a single eavesdropper, where all nodes are equipped with multiple antennas. No information regarding the eavesdropper is presumed at the transmitter, and we examine the MIMO downlink channel with either single or multiple data streams per receiver. The...
Two trends are reshaping wireless personal area networks (WPANs) and wireless local area networks (WLANs). The first is the convergence of WPAN and WLAN functionality in mobile platforms; a single 802.11 radio will increasingly be used for both functions. The second is the availability of new unlicensed spectrum in the 60 GHz band and 600 MHz TV Whitespace band as well as new technology enhancing...
A nonlocally weighted soft-constrained natural gradient iterative method is introduced for robust blind separation in reverberant environment. The scaling degree of freedom is controlled by soft-constraints built into the auxillary difference equations. The small divisor problem of iterations in silence durations of speech is resolved. Computations on synthetic speech mixtures based on measured binaural...
Statistical Kriging models for spatial data yield optimal linear estimates of unknown samples. In this work, we present a collection of statistical models defined over regions from a dyadic partition of the discrete Fourier spectrum. Spectral covariance models of the 2D Fast Fourier Transform (FFT) of aerial images allow for Kriging interpolation of magnitude and phase spectra from a small number...
In this paper, a novel technique for blind signal separation based on a combination of second order and higher order approaches is introduced. The problem of blind signal separation was solved in a wavelet domain. The main idea behind this approach is that the mixing signal can be decomposed into a sum of uncorrelated and/or independent sub-bands using the wavelet transform. In the beginning, the...
Multiple-Input Multiple-Output (MIMO) functionality has been shown to dramatically increase the capacity of wireless communication systems when the environment provides rich multipath scattering. In a predominantly Line-of-Sight (LOS) environment, the loss of diversity reduces the potential gain considerably. Recent studies have shown that systems which use a fully -polarimetric antenna such as triad...
Blind sources separation (BSS) arises in a variety of fields in speech processing such as speech enhancement, speakers diarization and identification. Generally, methods for BSS consider several observations of the same recording. Single microphone analysis is the worst underdetermined case, but, it's also the more realistic one. In our approach, the autoregressive structure (short term prediction)...
Deliberately designed bits-to-symbols mappings were introduced to provide significant coding gains compared to the simple Gray mapping for iteratively-decoded BICM on both AWGN and fading channels. The performance of these powerful mappings has always been illustrated in conjunction with relatively weak outer channel codes like convolutional codes with up to 16 states. However, when a powerful outer...
The Global Positioning System (GPS) is designed to estimate the locations of users or objects, and has a variety of civilian and military applications. Although angles-of-arrival (AOAs) may be required to enhance the desired GPS signals, it is difficult to estimate explicit AOA information because a GPS signal has a low power relative to the noise level. In this paper, we propose a GPS AOA estimation...
Hardware support for decimal arithmetic has become an important focal point, both in the research arena and in commercial processor developments. Like their binary counterparts, decimal multipliers can be designed in a variety of ways, offering area and speed trade-offs. Pipelined array multipliers support high throughput, making them attractive in multiply-intensive applications. We propose two different...
Cooperative Multi-User MIMO signaling across cells, also known as Network MIMO, has recently received a great deal of attention as a potential physical layer technique for future high-throughput wireless systems. Indeed, cooperative signaling is able to reduce inter-cell interference within groups of coordinated cells thereby improving system throughput. Such benefits, however, are often assessed...
This paper studies the issue of resource allocation in multiuser wireless networks with multiple service providers. We investigate the feasibility of modeling the resource allocation problem as a voting game and study the resulting strategic behaviors of the agents. In other words, competing transmitters are modeled as candidates in an election, while the receivers form the electorate. We study both...
Residue number system (RNS) representations, which allow fast addition and multiplication, have found niche applications in signal processing. These representations are based on integer-valued residue ??digits?? with respect to integer moduli. We introduce RNS representations with continuous or analog digits, and study their dynamic range, accuracy, and optimal choice of the moduli. Like positional...
This work considers a network with K transmitters and receivers, where the transmit-receive association is not predetermined. It is thus an interference network where the pairing between transmitters and receivers can be optimized to improve performance. This model is designed to represent a cellular system where each transmitter (mobile) is attempting to determine the best receiver (base-station)...
This work evaluates the peak-to-average power ratio (PAPR) performance in a coded orthogonal frequency-division multiplexing (C-OFDM) system using the selective mapping (SLM) approach. Repetition-coded side-information (SI) bits specifying which one of several possible phase sequences is being used are embedded in the data stream at the transmitter before convolutional coding, interleaving, and QAM...
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