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In this paper, we study the design of sparse graph based codes for Faster-Than-Nyquist (FTN) signaling. Using an asymptotic approach based on EXIT charts, we show that good low-density parity check codes can be designed that perform well under iterative detection and decoding and that have better performance than a FTN scheme using a code optimized for the additive white Gaussian noise channel.
QRS detection in exercise stress test recordings remains a challenging task, because they are highly non-stationary and contaminated with noises, such as large baseline wander and muscular noise, among others. The aim of this work is to find an optimal set of parameters for QRS detection in very noisy ECG signals, such as those acquired during stress tests. Parameter optimization was addressed by...
In order to get an enhanced image and for extracting useful information, an image is first converted into digital form and after that various operations are performed on it. Image edge detection is one of the most important preprocessing step in image processing. In this paper, we compare various traditional edge detection methods such as Canny, Prewitt, Robert and Sobel. Also we propose edge detection...
In this paper we investigate the node placement for a wireless sensor network deployed to sense the spectrum with spatial channel correlation. The goal is to find the best node constellation, such that the given power constraints are satisfied and the best sensing performance is acquired. We derive the analytical expression for probability of detection (PD) of the optimal test statistic as the measure...
Optimal channel switching and detector design is studied for M-ary communication systems in the presence of stochastic signaling, which facilitates randomization of signal values transmitted for each information symbol. Considering the presence of multiple additive noise channels (which can have non-Gaussian distributions in general) between a transmitter and a receiver, the joint optimization of...
Photo detector using together with anamorphic lens is presented. Optimization of both optical lens and electronic scheme is considered. Anamorphic lens design is investigated. Improvement calculation methods for optical part are discussed. Theoretical results of optical to electronic signal converter schematics are given. A signal to noise ratio influence for accuracy of measurement is analyzed. Possible...
We discuss solvability issues of ℋ−/ℋ2/∞ optimal fault detection problems in the most general setting. A solution approach is presented which successively reduces the initial problem to simpler ones. The last computational step generally may involve the solution of a non-standard ℋ−/ℋ2/∞ optimization problem for which we discuss possible solution approaches. Using an appropriate definition of the...
In this paper, we present an approach for edge detection using adaptive thresholding and Ant Colony Optimization (ACO) algorithm to obtain a well-connected image edge map. Initially, the edge map of the image is obtained using adaptive thresholding. The end points obtained using adaptive threshoding are calculated and the ants are placed at these points. The movement of the ants is guided by the local...
In this paper, stochastic signaling is studied for power-constrained scalar valued binary communications systems in the presence of uncertainties in channel state information (CSI). First, it is shown that, for a given decision rule at the receiver, stochastic signaling based on the available CSI at the transmitter results in a randomization between at most two different signal levels for each symbol...
A method for assessment detector's false alarm and fault was developed. It includes the assessments of noise intensity barriers and detector's vulnerability to them using fuzzy sets and their defuzzification. It allows considering different environmental influences that may cause improper functioning of the alarm systems.
In this paper, we review the state-of-the-art in neural interface recording architectures. Through this we identify schemes which show the trade-off between data information quality (lossiness), computation (i.e. power and area requirements) and the number of channels. We further extend these tradeoffs by band-limiting the signal through reducing the front-end amplifier bandwidth. We therefore explore...
Traditional edge detection approaches often result in broken edges especially in noisy images. This study presents a particle swarm optimisation based algorithm to detect edges continuously in such images. In this paper, a new objective function and a new encoding scheme are proposed to address noise and reduce broken edges. The newly developed algorithm is compared to a modified version of the Canny...
Motivated by the demand and the low utilization of spectrum resource, cognitive radio appears as an alternative for the present spectrum distribution policy. Spectrum sensing is the key procedure and energy detector is the most commonly used algorithm in spectrum sensing. The communication signal often varies by time, which causes the spectrum sensing to be inaccurate. In this paper, we use window...
In this paper, stochastic signaling is studied for scalar valued binary communications systems over additive noise channels in the presence of an average power constraint. For a given decision rule at the receiver, the effects of using stochastic signals for each symbol instead of conventional deterministic signals are investigated. First, sufficient conditions are derived to determine the cases in...
In this paper, we propose a cognitive MAC scheme which combines cooperative spectrum sensing and RTS-CTS scheme. The remainder of this paper is organized as follows. Section II describes the proposed scheme. Section III gives the mathematical derivation. Section IV gives numerical results.
A design of low-noise charge sensitive amplifier (CSA) for measurement of optical response of photo-detector registering light produced by semiconductor scintillator is presented. Detailed analysis of the CSA suitable for large parasitic detector capacitance is provided, regarding noise, power and stability. Two scenarios where input transistor is biased in strong inversion and weak inversion are...
In this paper, effects of signal randomization are studied for binary communications systems. First, it is stated that the average probability of error for a power-constrained binary communications system is minimized when each symbol is randomized between at most two signal values. Then, a fixed detector is considered, and sufficient conditions under which its performance can or cannot be improved...
In this work, a rule-based training method for the optimization of a fuzzy inference system that is used as a noise removal operator is presented. In this method, only the parameters processed in the current epoch, rather than all parameters of the fuzzy inference system, are replaced with the new candidate solutions when examining the neighboring solutions in the search space. In the parameter based...
Performance of some suboptimal detectors can be improved by adding independent noise to their observations. In this paper, the effects of adding independent noise to observations of a detector are investigated for binary composite hypothesis-testing problems in a generalized Neyman-Pearson framework. Sufficient conditions are derived to determine when performance of a detector can or cannot be improved...
We explore the feasibility of low probability of intercept for sonar signals. Using a noise-like active sonar signal, the transmitter (platform) employs a matched filter for echo detection while the target is assumed to use an energy detector. Decision statistic distributions are developed at both the platform and target. These distributions allow efficient Monte Carlo simulation of detection performance...
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