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Rove beetles (Coleoptera: Staphilinidae) are a group of diverse insects occurring in a range of different ecosystems, from the plains to the mountaintops. However, there are no reports in the literature of their presence in the tidal zone of the seashore. This is the first report of the presence of Paederus fuscipes Curtis on the coastal sands of the Caspian Sea, northern Iran. In all 14 counties...
In this paper accurate ranging using flexible wavelet packet modulation is addressed. Wavelet Packet modulated (WPM) signal can be used for joint communications and ranging (two functionalities in one technology). Using wavelet technology the optimal signal will be designed for the time-of-arrival (TOA) or time-difference-of-arrival (TDOA) ranging when there exists a synchronization error. The focus...
The ultimate goal of this study is to develop a comprehensive and competitive management system to enhance resilience capability of supply chains. In addition, the study aims to identify and eliminate barriers affecting resilience by identifying the factors may cause trouble in the near future. The theoretical framework was established to summarize the significant finding in the area of resilient...
In this paper, non-data aided (NDA) signal-to-noise ratio (SNR) estimation techniques for non-coherent on-off keying (OOK) receivers using non-equiprobable signal transmission is analyzed. Expectation-maximization (EM), M1M2 and M2M3 estimators are investigated. It is shown that the performance of moments based estimators degrade in high SNR region due to bad noise estimates. Moreover, lower moment...
This research is a case study research related to customer satisfaction, focuses on more effective service improvement and changes in regards with meeting the customer needs. Through empirical approach and related enterprises investigation, based on employees’ perspective and end-user’ perspective, it designs a questionnaire system to collect data. In a case company, totally 31 interviews were made...
In this paper, we investigate the Zero-Padding (ZP) Orthogonal Frequency Division Multiplexing (OFDM) technique to estimate Time Difference of Arrival (TDOA) in positioning applications. Statistical features of OFDM blocks (symbols) are adopted in this paper to achieve a bandwidth efficient transmission and a low computational burden for the TDOA estimation. We propose a multipath diversity scheme...
In wireless cognitive sensor networks the number of cognitive nodes for distributed beamforming should be large in order to reduce interference to primary users. The available optimal numbers of nodes selection schemes of distributed beamforming techniques do not address the cognitive radio scenarios and minimization of interference in the direction of primary users. In this paper a close to optimal...
In this paper, a 2D/3D UWB localization technique based on joint ToA/DoA in indoor dense multipath environment is proposed. In this method, direction of arrival (DoA) is estimated from time of arrival (ToA). The joint usage of ToA and DoA results in an accurate localization of the mobile node (MN). Unlike conventional methods, the proposed localization technique needs only one access point (AP) with...
A 2D UWB localization technique based on joint ToA/DoA in indoor dense multipath environment is proposed. In this method, direction of arrival (DoA) is estimated from time of arrival (ToA). The joint usage of ToA and DoA results in an accurate localization of the mobile node (MN). Unlike conventional methods, the proposed localization technique needs only one access point (AP) with an array structure...
Cognitive Radio (CR) is an intelligent radio system, which is capable of being aware of the communication environment and consequently adapts to it. With Null Broadening (NB) technique, CR can share the spectrum and coexist with licensed users (LU) by displaying nulls to a certain range of Direction of Arrival (DOA) of LU. In this paper, we present a new CR downlink beamforming method via combining...
Distributed Beamforming conserves power consumption of wireless sensor networks and extends communication range by focusing the transmit signal energy in the direction of the receiver. Significant saving of power consumption is obtained by only selecting the optimal number of nodes prior to beam forming which are necessary to form the communication link. A new node selection method based on clustering...
Distributed Beamforming conserves power consumption of wireless sensor networks and extends communication range by focusing the transmit signal energy in the direction of the receiver. Significant saving of power consumption is obtained by only selecting the optimal number of nodes prior to beam forming which are necessary to form the communication link. A new node selection method based on clustering...
Existing wireless channel models are based on statistical impulse response methods derived from empirical analyses. These algorithms are inefficient in signal representation and consume a lot of computational power. Meanwhile, the theory of wavelets and wavelet packets, which have recently found applicability in signal processing applications, hold great promise for wireless channel modeling. In this...
Wavelet Packet Modulation (WPM) is a multicarrier modulation technique like the well-established Orthogonal Frequency Division Multiplexing (OFDM). The channel equalization of WPM is important and unique due to the symbol overlap in time. In this article we present a time-domain equalizer for the compensation of channel induced distortions on the WPM transmission. The equalizer applies the principle...
In this paper, we investigate the relaying issue of Zero-Padding (ZP) Orthogonal Frequency Division Multiplexing (OFDM) technique to estimate Time Difference of Arrival (TDOA) for locationing applications. In order to benefit from the easy processing of Amplify-and-Forward (AF) relay as well as the noise and interference cancellation of Decode-and-Forward (DF) relay schemes, we introduce the trigger...
A reconfigurable wavelet packet transceiver for spectral analysis and dynamic spectrum access is proposed. The transceiver consists of a Wavelet Packet Spectral Estimator (WPSE) and a Wavelet Packet Multi-carrier Modulator (WPM) both of which are implemented using filter banks. The WPSE estimates the radio environment and identifies spectrum holes and occupied bands. This information is then used...
A wavelet packet transceiver for spectral analysis and dynamic spectrum access is presented. The transceiver consists of a Wavelet Packet Spectral Estimator (WPSE) and a Wavelet Packet Multi-carrier Modulator (WPM). The WPSE senses the radio environment to identify Licensed Users (LU) bands and spectrum holes. This information is then used to shape the time-frequency characteristics of the WPM transmission...
In this paper, we design a cooperative wavelet scheme for the multi-relay, multi-scale and multi-lag diversity, which can be widely applied in the ultra-wideband communications and underwater acoustic communications. A Decode-and-Forward (DF) cooperative relay network is set for the multi-scale and multi-lag wideband channels. Then, an analytical bit error rate (BER) expression for this DF cooperative...
In the cooperative communication system, due to the distributed nature of the relay system, multiple carrier frequency offsets (CFOs) at different relays and multipath channels between relays cause the whole cooperative communication channel to be a doubly time-frequency selective channel. Zero-Padding Orthogonal Frequency Division Multiplexing (ZP-OFDM), which has been adopted for some wideband communication...
Cognitive radio (CR) concepts were introduced by J. Mitola in 1999/2000. It is an approach with high potential to allow most-intensive usage of the precious natural source spectrum. CR is capable of sensing the communication environments and of adapting to its environment by adjusting the radio parameters. With beam-forming techniques, CR can direct its main beam towards CR users while creating nulls...
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