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Interference alignment (IA) has been proposed to optimally manage the interference aiming at providing the maximum degrees of freedom for multiuser interference channels. Therefore, IA has been used in cognitive radio (CR) systems to perform resource management in order to improve the throughput of the OFDM/FBMC based MIMO CR systems. In this work, a sub-optimal IA based power loading method is proposed...
In this paper, we present a radio resource allocation algorithm based on interference alignment (IA) for orthogonal frequency division multiplexing (OFDM) and filter bank multicarrier (FBMC) based MIMO cognitive radio (CR) systems. The algorithm provides the opportunity for all secondary users to share the available subcarriers simultaneously using IA technique. Besides, it allocates the power budget...
In this paper, we propose a novel scheme coined opportunistic space-time coding (OSTC) to deal with the outdated channel state information (CSI) problem for opportunistic relay selection (ORS) systems. A pair of relays, instead of a single relay, is opportunistically selected in terms of the instantaneous CSIs. Alamouti scheme, a unique space-time code achieving both full-rate and full-diversity,...
To rapidly deploy a communication network in the aftermath of disaster or emergency event, an Aerial-Terrestrial architecture integrating aerial base stations mounted on the balloons has been investigated in EU FP7 ABSOLUTE project. Since the signal coverage provided by aerial base stations is patchy and unstable, the opportunistic relaying is applied to increase the link reliability and the system...
To enable the rapid deployment of a public safety communication network, a novel system architecture integrating an aerial base station mounted on a low-altitude platform has drawn many attentions. However, the signal coverage provided by such a rapidly-deployed network is patchy and unstable, which conflict with the high requirement on link reliability in the case of disaster relief and emergency...
Up to now, a closed-form expression of the ergodic capacity for amplify-and-forward opportunistic relaying in the presence of outdated channel state information(CSI) is still not available in the literature. That is mainly due to the mathematical intractability in the conventional performance analysis through manipulations of probability density function (PDF). In this paper, therefore, we take advantage...
Recently, there has been an increasing interest in enhancing the mainstream cellular technology Long Term Evolution Advanced (LTE-A) with cognitive radio as one of the key enablers towards the fifth generation (5G) wireless communications. For dynamically accessing wider range of spectrum bands in a friendly manner, the cognitive LTE system should be able to discover the possible coexisting heterogeneous...
Until now, the performance analysis of Generalized Selection Combining (GSC) applied to cooperative diversity networks in the presence of outdated channel state information (CSI) is still not available in the literature. In this paper, therefore, we derive closed-form expressions of the ergodic capacity and outage probability for amplify-and-forward GSC over independent and identically distributed...
To combat the bottleneck effect in the relay channels, this paper proposes a simple power-control algorithm for decode-and-forward cooperative networks with opportunistic relay selection. Taking advantage of the existing channel state information, which is a by-product during the process of relay selection, an optimal power allocation factor can be easily figured out. This factor is quantized into...
In this paper a 3D-deterministic channel model for UWB chipless RFID system is presented. The tag in this work will be modeled as a 3D object, with frequency dependent Radar Cross Section (RCS), embedded in the channel which has several incident and reflected multipath at various directions both from the reader-tag and the reader-reader environment effect. In this model all channel effects as multipath...
The main limitation of any chipless Radio Frequency Identification (RFID) system is the very short reading range. In this paper, we propose an Ultra Wideband (UWB) Reflectarray Antenna (RA) system with 2.2 GHz bandwidth centered at 6 GHz for the reader of chipless RFID applications. The proposed reader antenna system enhances reader sensitivity, reduces multipath effects, helps in tag localization...
This paper presents a beamforming design for Multiple-Input Single-Output (MISO) Radio Frequency Identification (RFID) systems. The design insures good Quality of Service (QoS) as well as optimal total power transmitted by the reader. Furthermore, a solution using Second-Order Cone Programming (SOCP) for the RFID beamforming problem is proposed. This SOCP algorithm yields optimal beamforming weights...
AimThe aim of the present study was to investigate the impact of proangiogenic factors [erythropoetin (EPO), human growth hormone (HGH), fibroblast growth factor (FGF), and platelet derived growth factor (PDGF‐BB)] on the organization and biodegradation of a porcine‐derived collagen matrix (CM) in rats.
Material and methodsCollagen matrix specimens were soak‐loaded either with EPO, HGH, FGF or PDGF‐BB,...
This paper discusses the separation of signals in multiple-tag radio frequency identification (RFID) systems. First, a model for the RFID system in both single and multiple tag environments is presented. Then, an analytical constant modulus algorithm (ACMA) for the blind source separation problem is reviewed. An alternative approach to the traditional ACMA using joint diagonalization is considered...
This paper investigates active cancellation techniques for a Full-Duplex transceiver. An auxiliary transmit chain is employed to create the cancellation signal, which is then injected at the receiver RF front-end by using a microstrip cou-pler. Two methods are proposed to calculate the self-interference cancellation signal. While the first method assumes the transmit chain to be strictly linear, the...
This paper investigates a Full-Duplex transceiver using an active cancellation technique where an additional transmit chain is employed to create the self-interference cancellation signal. Both transmitters and also the receiver are impaired by frequency-dependent I/Q imbalance with different parameters. It is shown how an I/Q parameter deviation in these chains deteriorates the achievable self-interference...
In the research on spectrum sensing, many works focus on TV bands, in which primary user signals follow digital video broadcasting-terrestrial (DVB-T) standard. However, DVB-T2 is the next generation of this standard. Some characteristics of the primary signal are changed including the pilot pattern and the cyclic prefix (CP). This issue results that the existing sensing algorithms based on the characteristics...
In this paper, we propose a robust spectrum sensing scheme which can reliably detect signals in multiple channels within short observation time at the cost of low computational complexity. The scheme consists of two parts. The first part is the signal detection algorithm essentially based on the crosscorrelation of the feature sequence generated utilizing the signal's periodical pilot structure, which...
Linear least squares (LLS) estimation is a sub- optimum but low-complexity localization method based on measurements of location-related parameters. It has been proved that selection of the reference anchor influences the LLS localization accuracy. In addition, hybridization of different types of measurements can fix the deficiencies of one type of measurements. In this paper, we proposed a new reference...
This paper presents a robust radio access technology (RAT) classification framework for acquiring comprehensive knowledge on multiple types of coexisting wireless systems. It is built upon the combination of a group of RAT-specific feature metrics using maximum likelihood estimation (MIE) based decision rules. The classification scheme is enhanced by our proposed dimension cancellation (DIC) method...
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