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.
Orthogonal frequency division multiplexing access (OFDMA) inherently suffers from large spectral sidelobes, which will lead to interference between users and can not be ignored. In this paper, in order to suppress spectral sidelobes, we propose a novel windowing scheme. The derivation of the optimum window function is based on the solution of an optimization problem. It aims to minimize in-band-out-of-subband...
In the scenario of multiple access communication, the spectral sidelobes and peak-to-average power radio (PAPR) problems of orthogonal frequency division multiplexing (OFDM) must not be ignored. This paper proposes a novel precoding scheme that ahead of inverse discrete Fourier transformation (IDFT) is presented to jointly suppress the in-band-out-of-subband (IBOSB) radiation and high PAPR in orthogonal...
Extreme Learning Machine (ELM) is a promising single hidden layer feed-forward neural network learning method, which achieves fast learning by randomly tuning the hidden layer. In this paper, we propose a self-expression ELM (SeELM) for olfactory target/background detection. Specially, it is known that metal oxide semiconductor (MOS) sensor in electronic nose (E-nose) can response to several target...
Recently, researches on mobile cognitive radio network (CRN) has been paid more attention to, involving spectrum sensing, power control and spectrum access, while no schemes considering both the power and spectrum assignment at the same time. In this paper, an efficient resource allocation (RA) scheme is proposed for the orthogonal frequency division multiple access (OFDMA)-based mobile underlay CRN...
When making 4G sites planning scheme, telecom operators prefer to reuse the existing 2G/3G site resources to reduce capital and operating expenditure. However, 4G is a typical co-frequency interference network with characteristics of hard handover and mode 3 interference. Thus, it is of great significance to identify the high-risk original 2G/3G sites which may cause interference problem. Based on...
We report the complex dynamics observed in a nonlinear delayed feedback oscillator with silicon Mach-Zehnder electro-optic modulator. Period-doubling bifurcation, period-three signal, virtual chimera states and chaotic signal are observed.
SAR complex image registration is one of the key steps of the interferometirc SAR and tomographic SAR. The complex correlation function based method is an common registration method. Generally in the application, the adopted SAR complex image is large width, however, the complex correlation functions of registration accuracy can only be guaranteed the high precision of a small scale registration in...
Interference assessment is a fundamental problem in communication jamming systems, while existing approaches are still far away from being practically used in real applications. With the increasing intensity of jamming signals, the original audio signal is largely covered up and SNR is very low. As a results, traditional assessments are not able to achieve reliable performance. In this paper, we focus...
In this paper, we propose a novel resource allocation (RA) scheme based on interference minimization (IM) for cognitive radio networks (CRN). In the approach, we focus on an efficient scheme of subchannels assignment, power allocation and access control for the orthogonal frequency division multiple access (OFDMA)-based secondary users (SUs), accessing licensed spectrums of primary users (PUs) with...
This paper aims to investigate the resource allocation problem in a relay-assisted OFDMA cognitive radio (CR) system. Different from conventional CR resource allocation problems, a joint bandwidth and power optimization framework using the bandwidth-power product metric is proposed. Besides, rate requirement of the secondary system is satisfied and interference power at the primary receiver is limited...
We illustrate a 2×2 quantum photonic switch fabric using two-photon quantum interference in an integrated silicon microring resonator array. Our modeling demonstrates phase- or wavelength-selective routing of single photons at different output states.
In today's network-centric battlefield, the ad hoc style, self-organizing networks play a more and more important role in the operation of mobile forces that are deployed quickly to meet the tactical demands. However, the unique features of the tactical scenario also pose significant challenges for networking, which makes the existing research results for the general mobile ad hoc networks (MANETs)...
In cognitive vehicular networks, cooperation transmission has many advantages to access licensed spectrum under interference constraints, by exploring space diversity of vehicles. And in the urban city, there are many candidate vehicles can be a cooperation relay especially when traffic congestion. Recently many papers concern about cognitive multi-hop network, but most of them only analyzed the performance...
Magnetic resonance sounding (MRS) signal is quite weak. Usually it is very susceptible to outside noise interference when measured using MRS groundwater detector, so that the characteristic parameters extracted from the returned signal data are inaccurate; eventually leading to an inaccurate location of groundwater through inversion explanation. And because of the high sampling frequency and large...
Cognitive radio is a promising technology to improve the spectrum utilization by allowing the unlicensed (secondary) user share a frequency bandwidth with the licensed (primary) owner under the condition that no harmful interference is imposed on the licensee. In this paper, we analyze the spatial spectrum utilization efficiency of underlay cognitive radio transmission. In particular, we apply the...
Cognitive radio networks have recently emerged as an exciting technology to deal with the stringent requirement and scarcity of the radio spectrum. However, the secondary user (SU) usually needs to deal with a fundamental tradeoff between maximizing its own transmission throughput and minimizing the amount of interference caused to the primary user (PU). Accordingly dynamic resource allocation (DRA)...
Power electronic equipments generate differential-mode (DM) and common-mode (CM) interference simultaneously, both the propagation path and suppression method of these interferences are different. For reducing cost of interference suppression, it is very useful to identify the CM interference and DM interference in power electronic equipments, especially in the high-power equipments. The principle,...
A novel constant modulus algorithm (CMA) is proposed based on a uniformly spaced linear array by constraining its weight vector to a specific conjugate symmetric form. The constraint is derived from the beamformer with an optimum output signal to interference plus noise ratio (SINR). The effect of the additional constraint is equivalent to adding a second step to the original adaptive algorithm. With...
A novel adaptive beamforming algorithm is proposed based on a uniformly spaced linear antenna array by constraining its weight vector to a specific conjugate symmetric form. Two sets of constraints (linear and quadratic) are imposed on the beamformer while minimizing its output variance. Compared to the traditional linearly constrained minimum variance (LCMV) beamforming algorithm, the proposed one...
This paper considers highly efficient jamming resilient wireless system design. First, we introduce a collision free frequency hopping (CFFH) system based on the OFDMA framework and an innovative secure subcarrier assignment scheme. The secure subcarrier assignment algorithm is designed to ensure that: (i) Each user hops to a new set of subcarriers in a pseudo-random manner at the beginning of each...
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.