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In order to meet the request of ultra wideband (UWB) system to antenna, In this paper, a kind of Vivaldi antenna with ripple is designed, and its array is studied. Its working frequency band is from 400MHz to 900MHz, the gain of the antenna array unit in the low frequency band is 5.11dB, and 8.68dB in the high frequency band. In addition, we studied the antenna array respectively according to Dolph-chebyshef...
Distributed Hash Tables (DHTs) have emerged as the most popular scheme in the P2P network, which have drastically changed the way we share resources and gather information. In order to solve the problem of search flexibility In DHT, an improved lookup and routing protocol based on Content Addressable Networks (CANs) is proposed, which not only preserves CANs' simplicity, but also achieves a resilient...
This paper studies the accuracy of a fully-distributed pattern recognition algorithm, namely the P2P-GN, with imbalanced datasets problem which is often neglected by most of the available distributed algorithms. A major distinction of the P2P-GN compared to the other approaches is that it forms a single global classifier, instead of building many local classifiers (one at every site). Fine-granularity...
In this paper we propose a compressive channel estimation for fast fading channel in orthogonal frequency division multiplexing (OFDM) systems. We formulate the sparse compressive sensing (CS) problem by exploiting the delay-Doppler sparse structure of the doubly dispersive channel. To combat the severe inter-carrier interference (ICI) caused by the Doppler shift, this estimator is based on the banded...
In this paper, we analysis the three communication systems, orthogonal frequency division multiplexing (OFDM) system, single carrier modulation (SCM) system and hybrid carrier modulation (HCM) system under doubly selective (DS) channels. The implement structures of three systems have been derived. We then explore the property of SCM and OFDM systems. Furthermore, we, through numerical simulations,...
In this paper, we propose a relay selection method in an amplify-and-forward (AF) scenario considering complete outdated channel state information (CSI) of all links. Differing from the methods in the literatures considering only outdated CSI over the link from the relay to the destination, another type of outdated CSI, i.e., the outdated CSI over the link from the source to the relay, is also considered...
Little is known about disadvantaged people's adoption and use of mobile Internet services in such a global mobile technologies age. This paper aims to fill this gap by identifying enablers that affect disadvantaged people's adoption and use of mobile Internet services. We present the preliminary results from a qualitative user study with 21 participants, including twelve urban migrant workers and...
Data visualizations have become an integral role for management system. It not only allows users to witness, explore and understand large amounts of information, but also convey information more directly expressed. This paper presents how to use JavaScript third-party library such as Flot and D3.js for collection, analysis, processing and visualization of data by using Ajax.
For cognitive radio, dynamic spectrum access is a promising development direction. Dynamic spectrum access mechanism which is considered in this paper is a kind of channel reservation mechanism. Unlike most of the existing channel reservation mechanism, it is considered that the channel is reserved exclusively for unauthorized users in this paper. This reserved channel can only allow unauthorized...
Resource allocation and user association are two key issues in the heterogeneous wireless cellular networks. The joint optimization on these two problems is considered as NP-hard and hence it is difficult to achieve the exact solution effectively. In this paper a novel shareable resource allocation and user association scheme is proposed with frequency reusing taken into consideration. The optimization...
According to the Convergence of a vehicle and IT, In-Vehicle-Network (IVN) is complicated and the multimedia data is increased. Ethernet guarantees Quality of Service (Qos) of the existing Control Area Network (CAN) communication and has a high bandwidth. As a result, the Ethernet is recently developed a new standard. IEEE 802.1 Audio Video Bridging (AVB) supports to handle priority and queuing for...
The lightpath provision issue is a major challenge in multi-domain software defined optical networks, due to lack of topology and resources information exchangement among domains. Based on the Hierarchical PCE (H-PCE) architecture, this article proposed a Fast Lighpath Provision Mechanism (FLPM) to provide a more rapid inter-domain path establishment solution and decrease the influence of requirement...
A typical multi-layer satellite communication network structure is proposed according to the features of satellite communication network. The process of combat under satellite communication network support is analyzed based on OODA (observe, orient, decide, act) theory. The pi-calculus syntax is defined with extension, and it is used as a new pi-calculus formally modeling method. The process of combat...
Poisson random network was widely used in research on wireless communication and network recently. We utilized Poisson random network to construct the model for visible light communication. Detailed derivation of approximately analytical expression for SINR of visible light communication was given. The correctness and effectiveness of our approach was verified via numerical simulation. Our result...
Based on the characteristics of channel noise of Super Low Frequency (SLF) channel which is mainly formed with white Gaussian noise and impulse noise caused by thunders, and displays an obvious non-Gaussian feature, the thesis proceeds an analysis on multiple channels coding, designs a channel coding scheme for SLF communication and carries out a simulation analysis.
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