The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
The assumption of additive white Gaussian noise (AWGN) to model measurement is not valid since many applications such as in RF power measurement the noise is colored with 1/f spectrum characteristics. With this characteristics, the assumption of independently identically distribution (IID) used in signal detection and estimation becomes not valid. The autocorrelation function and power spectrum can...
In 5G wireless communication systems, steerable beamforming techniques will become one of the techniques that will draw high attention in telecommunication industries. The steerable beamforming technique not only provides high throughput, but also increases the capacity of the system. Furthermore, steerable beamforming techniques hold the potential to overcome the interference problem in dense deployment...
The recovery of original signals from the communication channel without any noise is a difficult task. Many denoising techniques have been proposed for the removal of noises from a digital signal. Wavelet denoising using threshold algorithm is a powerful method for suppressing noise in digital signals. In this paper, an audio denoising technique based on double-density dual-tree discrete wavelet transform...
In the field of communication, one of the most thriving and prevalent subject is the channel coding. Channel coding generally deals with the bandwidth which is the bit-rate or information storage capacity. It is a technical field which relies heavily on cost. In fact, it is undeniable that cost is the most crucial element in every system. Nowadays, together with the latency or time element which is...
In this paper, the quantity of interference on the primary user (PU) caused by the secondary user (SU) is investigated. An underlay spectrum sharing network is considered, where the different scenario of PU activity is modeled based on the duty cycle of PU channel. PU channel is classified into several activities according to the application of primary services. The interference to PU is observed...
The channels in a high-speed train (HST) environment are very quickly time-varying within an OFDM symbol so it is preferable to have their estimation and symbol detection to be simultaneously implemented. Time-varying characteristics of the channels also causes unavoidable inter-carrier interferences, which make both channel estimation and symbol detection doubly difficult. Considered in this paper...
In this paper, we propose a hierarchical Bayesian model approximating the ℓ20 mixed-norm regularization by a multivariate Bernoulli Laplace prior to solve the EEG inverse problem by promoting spatial structured sparsity. The posterior distribution of this model is too complex to derive closed-form expressions of the standard Bayesian estimators. An MCMC method is proposed to sample this posterior...
Estimation of a signal transmitted through a communication channel usually involves channel identification. This scenario can be modeled as random parameter estimation in the presence of unknown deterministic parameter. In this paper, we address the question of how accurately one can estimate a random signal intercepted by an array of sensors, subject to an unknown deterministic array response. The...
We study the impact of signal reflections in enclosed wireless networks of wearable devices operating at mmWave frequencies. Given the radical blockage by obstacles and people (including the user's own body) at these frequencies, surface reflections are expected to be very important contributors to the collection of an adequate amount of desired signal power. At the same time, they are also expected...
Adaptive detection of a Swerling I–II type target in Gaussian noise with unknown covariance matrix is addressed in this paper. The most celebrated approach to this problem is Kelly's generalized likelihood ratio test (GLRT), derived under the hypothesis of deterministic target amplitudes. While this conditional model is ubiquitous, we investigate here the equivalent GLR approach for an unconditional...
In this work, we propose a novel approach to multiple measurement vector (MMV) compressed sensing. We show that by exploiting the statistical properties of the sources, we can do better than previously derived lower bounds in this context. We show that in the MMV case, we can identify the active sources with fewer sensors than sources. We first develop a general framework for recovering the sparsity...
We study energy-efficient decentralized coordinated beam-forming in multi-cell multiuser multiple-input single-output system. The problem of interest is to maximize the weighted sum energy efficiency subject to user-specific quality of service constraints. The original problem is iteratively approximated as a convex program according to successive convex approximation (SCA) principle. The convex problem...
We present the concept of adversarial audio in the context of deep neural networks (DNNs) for music content analysis. An adversary is an algorithm that makes minor perturbations to an input that cause major repercussions to the system response. In particular, we design an adversary for a DNN that takes as input short-time spectral magnitudes of recorded music and outputs a high-level music descriptor...
Classical Radio Frequency IDentification (RFID) schemes such as Frame Slotted ALOHA (FSA) try to avoid colliding tag responses in the acquisition phase. We propose a scheme that exploits collisions in the acquisition phase, which is enabled by compressed sensing techniques. As an extension to previous work, it allows a more flexible usage of the compressed sensing-based approach for RFID. All activated...
General technique of template data preparation is proposed for the tasks of visual correlation-extreme navigation, which includes the image and its descriptive representation. Descriptive representation is based on Speed-Up Robust Feature (SURF) method. The requirements and structure of database of unified template are developed including the integral index of fragment informativity. Experimental...
We explore the applicability of electron-multiplying CCD (EMCCD) cameras to the problem of speckle imaging, i.e. imaging through atmospheric turbulence by processing short-exposure images. Signal-to-noise ratio expressions are derived for image and power spectrum estimates obtained from conventional and EMCCD cameras. An unbiased estimator for the bispectrum from EMCCD data is derived. Bispectrum...
The capacity of the intensity-modulation direct-detection (IM-DD) free-space optical channel with both average and peak intensity constraints is studied. A new capacity lower bound is derived by using a truncated-Gaussian input distribution. Numerical evaluation shows that this capacity lower bound is nearly tight at high signal-to-noise ratio (SNR), while it is shown analytically that the gap to...
We consider a the problem of coherently combining signals having several sinusoidal components as measured via multiple sensors, in which each sensor has its own transfer function. It is desirable to combine the sensor outputs to improve the signal-to-noise ratio, but simply co-adding the signals could result in signal cancellation, due to phase changes in the sensors. We propose here a combining...
In this paper, we develop randomized simultaneous orthogonal matching pursuit (RandSOMP) algorithm which computes an approximation of the Bayesian minimum mean-squared error (MMSE) estimate of an unknown rowsparse signal matrix. The approximation is based on greedy iterations, as in SOMP, and it elegantly incorporates the prior knowledge of the probability distribution of the signal and noise matrices...
In the preceding works on the tree networks composed of binary symmetric channel (BSC), the path diversity effects are discussed in [8]–[10]. In [9], it is shown that the error probability of majority decision at the fusion center is almost constant regardless of network size. This constant property of error probability has not been discussed theoretically. In this paper, a new approach of signal-to-noise...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.