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In this paper, we propose an adaptive group-based cooperative spectrum sensing scheme to maximize the spectrum efficiency without degrading the sensing accuracy. We consider cooperating secondary users with non-identical energy thresholds and average signal-to-noise ratio which will be represented by non-identical local probabilities of detection and false alarm. We formulate the throughput efficiency...
The paper investigates the signal-to-noise ratio (SNR) threshold effect in estimating the frequency and phase of a single sinusoid over the additive white Gaussian noise. This is done by making use of the results on the time-domain, phase-based estimator and the additive observation phase noise (AOPN) models developed in [8]. Specifically, the relationship between the threshold SNR and the similarity/dissimilarity...
We propose a simple, yet accurate, interference prediction model using the widely used two-ring hexagonal network layout in the absence or presence of shadowing. The proposed model only considers two dominant interferers out of the 18 ones that surround the serving base station. The proposed model, in contrast to the fluid model, takes the radial direction into account. This makes our proposed model...
In this paper, we consider Quality-of-Information (QoI) aware transmission policies for a dynamic environment. In particular, we focus on the time-varying nature of the observation quality of the environment in practical networks which leads to uncertainty in satisfying QoI requirements specified by end users. The goal of this paper is to meet QoI requests from end users with minimum resources. Specifically,...
Recently, carrying control signals on passing data packets has emerged as a promising direction for efficient control information transmission. With control messages carried on data payload, the extra air time needed for control packets like RTS/CTS is eliminated and thus channel utilization is improved. However, carrying control signals on the data payload of a packet requires the data packet to...
The two-point moment generating function (MGF) matching technique has been used with some success to approximate the output from an MRC diversity combiner operating in correlated lognormal fading channels. The technique, however, is very sensitive to the choice of the location of the two matching points. This paper proposes to apply the principle of power conservation across the combiner to control...
Amplitude and phase comparison methods are practical direction finding (DF) techniques for electronic support and electronic intelligence systems. The combination of amplitude and phase comparison methods improves the direction finding accuracy and at the same time the ambiguities of phase comparison method are resolved by amplitude comparison method. In this research, the important factors that affect...
Wild bootstrap resampling technique was proposed to improve parameter estimations of intra-voxel incoherent motion (IVIM) MRI, i.e. diffusion fraction (f), diffusion (D) and pseudo-diffusion (D∗), without increasing scan time. It was verified via simulation and clinical scan. In simulation, estimation accuracy and uncertainty obtained from asymptotic fitting with and without wild bootstrapping were...
This paper represents a preliminary study of cooperative positioning in Long Term Evolution (LTE) systems. Many applications, such as location-based services and Enhanced 911 (E911), require that the locations of users in a cellular system are available. The global navigation satellite system (GNSS) is the most accessible positioning systems which are widely used in cellphones. However, poor operation...
A new denoising technique for preprocessing of P300 and Slow Cortical Potential (SCP)-based Brain computer interface data is proposed. This new technique adaptively removes the superimposed noise using a modified version of spectral subtraction method. A better performance is achieved especially when less number of electrodes is used which accordingly reduce weight and consumed power for portable...
In 1976, Massey introduced a method to compute the confidence interval for the frame error rate of a coded communications system based on the simulation of just a few frame errors [1]. He commented that his approach did not apply to bit error rate confidence intervals, because bit errors are not independent in a coded system. In this paper, we show how to overcome the limitation Massey recognized,...
Directivity, as a characteristic parameter of electromagnetic radiation source, could be used to classify different radiation sources, and the ESD events could be considered as typical sources. The parameter could be measured by electric field intensity radiating in all directions in the space. In this paper, we would build three basic antenna models which are all working at 3GHz and set cube receiving...
In this work we propose a grid-based method to estimate the location of multiple sources in a wireless acoustic sensor network, where each sensor node contains a microphone array and only transmits direction-of-arrival (DOA) estimates in each time interval, minimizing the transmissions to the central processing node. We present new work on modeling the DOA estimation error in such a scenario. Through...
A technique for interrogation of fiber-optic extrinsic Fabry-Perot interferometry sensors, based on adaptive filtering, is reported. This approach achieves 9.6 pm accuracy on Fabry-Perot cavity length (equivalent to 0.045 mmHg pressure) and improved noise resilience.
Equivalent time sampling causes noise in reconstructed pulse stream due to the transmitter or receiver jitter or path variations. When this pulse stream is used for localization, system accuracy is limited by the reconstructed pulse signal to noise ratio (SNR). In this paper, the jitter effects from transmitter and receiver on reconstructed pulse are simulated and an improvement technique based on...
The time difference of arrival (TDOA) positioning method is a classic method that is used to determine the unknown location of a transmitting wireless terminal, based on the time differences in the signals that are received at different receivers. In this research the method is studied for two- dimensional (2-D) problems for simplicity, for an electromagnetic dipole source radiating a carrier wave...
A novel concept for determining Direction of Arrival estimation (DOAE) of air target has been investigated. The methodology relies on the echo signal inducing a known spatially varying electric field. In Uniform Linear Array (ULA), the elevation angle is estimated by multiresolution ESPRIT (MRESPRIT) method. The efficacy of the proposed algorithm is verified by Monte Carlo simulation, DOAE accuracy...
We introduce, in this paper, a simplified architecture of the Minimum and Maximum Spread (MMS) estimation method, entitled the modified Minimum and Maximum Spread (mMMS) estimation method. The mMMS method aims to detect the neural spikes efficiently. Both detectors, with different buffer sizes, are designed and implemented. Through simulation, it is shown that the circuit implemented with the mMMS...
This paper investigates a hybrid technique that uses a combined version of Received Signal Strength (RSS) and Direction of arrival (DOA) localization techniques. Simulation results prove that using the hybrid technique in one node increases the localization accuracy and provides the node with the capability of localizing other nodes by itself without any assistance from other nodes. The performance...
Noise is the key to cause phase measurement error of sine signals. Although there have been many attempts to suppress noise interference, high accuracy is still hard to meet in terrible noise environment. In order to improve reliability and accuracy of the measurement system, a robust method is proposed. In this paper, independent component analysis (ICA) is used to separate sine signal from noises...
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