《电信技术》面对新媒体挑战的应对

面对新媒体咄咄逼人的侵入，很多专业期刊正处于“兵临城下”的境地。那么专业期刊怎样才能找到自己的突围之路，开拓一片新的疆土呢？在将近60年的运营过程中，《电信技术》经受住了市场的锤炼和考验。本文结合《电信技术》杂志的具体实践，探讨专业期刊应该如何应对新媒体的强势冲击。

用我们的努力推动国民经济与社会信息化的前进：人民邮电出版社社长杜肤生谈《电信技术衫大典》的出版

在刚刚过去的国际通信展上，在人民邮电出版社二的展台上，一本刚刚出版的大型实用工具书《电信技术实用大典》吸引了许多参观者的目光，许多技术人员和管理人员都把它作为案头必备工具书争相购买。据了解，这本书出版以来，已受到各方的好评，新华社也做了相关报道。

5G移动通信在电力通信中的运用与关键技术探究

5G移动通信可以使网络的传输更加稳定和快速,不论是在人们的日常生活,还是工作学习中,通过对5G移动通信的应用,可以提供更加智能和优质的服务。5G本身具备的科技优势非常强大,在如今的通信技术中,具备前沿性的特点,而在未来通信的发展中,其必然成为主流的发展趋势。文章主要对5G移动通信在电力通信中的运用与关键技术进行深入的探究。

An Overview of the Smart Grid in Great Britain

This paper presents an overview of the current status of the development of the smart grid in Great Britain(GB).The definition,policy and technical drivers,incentive mechanisms,technological focus,and the industry's progress in developing the smart grid are described.In particular,the Low Carbon Networks Fund and Electricity Network Innovation Competition projects,together with the rollout of smart metering,are detailed.A more observable,controllable,automated,and integrated electricity network will be supported by these investments in conjunction with smart meter installation.It is found that the focus has mainly been on distribution networks as well as on real-time flows of information and interaction between suppliers and consumers facilitated by improved information and communications technology,active power flow management,demand management,and energy storage.The learning from the GB smart grid initiatives will provide valuable guidelines for future smart grid development in GB and other countries.

New Optimal Power Allocation for Bidirectional Communications in Cognitive Relay Network Using Analog Network Coding

Cognitive radio and cooperative communication can greatly improve the spectrum efficiency in wireless communications.We study a cognitive radio network where two secondary source terminals exchange their information with the assistance of a relay node under interference power constraints.In order to enhance the transmit rate and maintain fairness between two source terminals,a practical 2-phase analog network coding protocol is adopted and its optimal power allocation algorithm is proposed.Numerical results verify the superiority of the proposed algorithm over the conventional direct transmission protocol and 4-phase amplify-and-forward relay protocol.

Telecentres in Mountain Regions-A Peruvian Case Study of the Impact of Information and Communication Technologies on Remoteness and Exclusion

Communities in developing country mountain areas,in part due to their remoteness,find themselves excluded from social,political and economic systems; and excluded from access to resources. This paper aims to study the impact of information and communication technologies (ICTs) on remoteness and exclusion. It utilises two models - the resource movement framework,and the "information chain" - to analyse a telecentre in one district of mountainous Huancavelica,Peru's poorest region,set in the high Andes. It finds ICTs enabling new and positive resource flows for the two key user groups:teenaged school students and young farmers. These help to maintain social networks. They also support information searches that have improved agricultural practice where other information chain resources have been available. But non-use and ineffective use of the telecentre are found where information chain resources are lacking. ICTs have some impacts on intangible elements of remoteness. In this particular example,they also offer access to some previously-excluded resources. But they have not really addressed the systematic exclusions faced by mountain communities. And they so far appear to be a technology of inequality; favouring those residents who begin with better resource endowments.The paper concludes by offering some recommendations for mountain ICT project practice.

Energy-Efficient Architecture and Technologies for Device to Device(D2D) Based Proximity Service

Considering that modern mobile terminals possess the capability to detect users' proximity,and offer means to directly communicate and share content with the people in close area,Device-to-Device(D2D) based Proximity Services(ProSe) have recently witnessed great development,which enable users to seek for and utilize relevant value in their physical proximity,and are capable to create numerous new mobile service opportunities.However,without a breakthrough in battery technology,the energy will be the biggest limitation for ProSe.Through incorporating the features of ProSe(D2D communication technologies,abundant built-in sensors,localization-dependent,and context-aware,etc.),this paper thoroughly investigates the energy-efficient architecture and technologies for ProSe from the following four aspects:underlying networking technology,localization,application and architecture features,context-aware and user interactions.Besides exploring specific energy-efficient schemes pertaining to each aspect,this paper offers a perspective for research and applications.In brief,through classifying,summarizing and optimizing the multiple efforts on studying,modeling and reducing energy consumption for ProSe on mobile devices,the paper would provide guide for developers to build energy-efficient ProSe.

PROJECTED GRADIENT DESCENT BASED ON SOFT THRESHOLDING IN MATRIX COMPLETION

Matrix completion is the extension of compressed sensing.In compressed sensing,we solve the underdetermined equations using sparsity prior of the unknown signals.However,in matrix completion,we solve the underdetermined equations based on sparsity prior in singular values set of the unknown matrix,which also calls low-rank prior of the unknown matrix.This paper firstly introduces basic concept of matrix completion,analyses the matrix suitably used in matrix completion,and shows that such matrix should satisfy two conditions:low rank and incoherence property.Then the paper provides three reconstruction algorithms commonly used in matrix completion:singular value thresholding algorithm,singular value projection,and atomic decomposition for minimum rank approximation,puts forward their shortcoming to know the rank of original matrix.The Projected Gradient Descent based on Soft Thresholding(STPGD),proposed in this paper predicts the rank of unknown matrix using soft thresholding,and iteratives based on projected gradient descent,thus it could estimate the rank of unknown matrix exactly with low computational complexity,this is verified by numerical experiments.We also analyze the convergence and computational complexity of the STPGD algorithm,point out this algorithm is guaranteed to converge,and analyse the number of iterations needed to reach reconstruction error.Compared the computational complexity of the STPGD algorithm to other algorithms,we draw the conclusion that the STPGD algorithm not only reduces the computational complexity,but also improves the precision of the reconstruction solution.

Digital Filter Algorithm Based on Morphological Lifting Scheme and Median Filter

Abstract--When the circuits in which electronic products are fitted are disturbed by various interrupting signals, wave distortions occur to the normal voltage signals of these circuits. These wave distortions influence the normal operation and life cycle of electronic products. To eliminate the harmful effects of interrupting signals on electronic products, in this paper, a digital filter algorithm based on morphological lifting scheme and median filter （MLS-MF）, which will be used to filter various interrupting signals existing in the circuits in which electronic products are fitted, is proposed. A variety of interrupting sig- nals have been included in simulation studies, and simulation results have demonstrated the effectiveness and feasibility of the proposed digital filter algorithm in high frequency continuous interference, random background noise and damped oscillatory transient interference filter. Index Terms--Digital filter, lifting scheme, median filter, mor- phology.

High Performance Viterbi Decoder on Cell/B.E.

Viterbi decoding is widely used in many radio systems. Because of the large computation complexity, it is usually implemented with ASIC chips, FPGA chips, or optimized hardware accelerators. With the rapid development of the multicore technology, multicore platforms become a reasonable choice for software radio (SR) systems. The Cell Broadband Engine processor is a state-of-art multi-core processor designed by Sony, Toshiba, and IBM. In this paper, we present a 64-state soft input Viterbi decoder for WiMAX SR Baseband system based on the Cell processor. With one Synergistic Processor Element (SPE) of a Cell Processor running at 3.2GHz, our Viterbi decoder can achieve the throughput up to 30Mb/s to decode the tail-biting convolutional code. The performance demonstrates that the proposed Viterbi decoding implementation is very efficient. Moreover, the Viterbi decoder can be easily integrated to the SR system and can provide a highly integrated SR solution. The optimization methodology in this module design can be extended to other modules on Cell platform.

Applications of IoT in Smart Grid

In this paper,the basic requirements of the smart grid in China are studied.By applying Internet of Things(IoT) technologies,various intelligent services can be created.The development of the smart grid would rely heavily on the application of IoT.The three-layer architecture of IoT for the smart grid in China is introduced.Various information and communication technologies of IoT applied to smart grid are discussed.Particularly,several typical IoT application solutions such as power transmission line monitoring,smart patrol,smart home and electric vehicle management,are provided.

BOOTSTRAPPING FOR EXTRACTING RELATIONS FROM LARGE CORPORA

A new approach of relation extraction is described in this paper. It adopts a bootstrap- ping model with a novel iteration strategy, which generates more precise examples of specific relation. Compared with previous methods, the proposed method has three main advantages: first, it needs less manual intervention; second, more abundant and reasonable information are introduced to represent a relation pattern; third, it reduces the risk of circular dependency occurrence in bootstrapping. Scalable evaluation methodology and metrics are developed for our task with comparable techniques over TianWang 100G corpus. The experimental results show that it can get 90% precision and have excellent expansibility.

A new broadband differential phase shifter fabricated using a novel CRLH structure

Broadband phase shifters are mostly proposed and fabricated based on the scheme proposed by Shiffman, which uses a coupled line with far ends connected together and a uniform transmission line to give a differential phase shift. Based on the unique dispersion property of the composite right/left-handed (CRLH) metamaterial structure, a new configuration is presented in this paper for fabricating the broadband differential phase shifter, which employs a novel CRLH metamaterial structure as one of the differential phase-shift arms, instead of the conventional coupled line. The new circuit can achieve a phase shift of 90° in an operational bandwidth as broad as one octave and its phase deviations are quite small. An original design of the novel broadband phase shifter is presented, in which the artificial CRLH structure was implemented by microstrip quasi-lumped elements. Both the simulated and measured results of the 90° broadband differential phase shifter are presented.

Application of the High-resolution EM Method in the Investigation of B Tunnel

A successful case history of exploring for concealed structure using the high-resolution EM method in the investigation of the West-East Gas Pipeline Project＇s B Tunnel is presented in this paper. The high frequency electromagnetic image system named STRATAGEM EH4, operating at frequencies ranging from 90KHz to 1Hz, was used for data acquisition. The orthogonal components of the electromagnetic field were measured during the field acquisition and the relevant electromagnetic attributes of the object body were extracted from the electromagnetic data. Hybrid sources, consisting of natural and full tensor-controlled sources, were utilized to produce high-quality electromagnetic field data. B Tunnel lies in the western part of Hubei province, at depths of less than 200m. The geologic setting of B tunnel is very complex. Following an initial geologic investigation, an outcrop considered to be a bedrock interface by investigators, collapsed during tunneling operations. A second investigation applied high-resolution EM and seismic refraction methods to reveal a more complex geologic structure along the tunnel route. The predicted rock classes and fault were encountered during the subsequent tunneling operations.

Spatially localized and joint access point selection for Wi-Fi indoor positioning

Wi-Fi indoor positioning system has received increasing interest in pervasive computing applications due to its low cost and satisfactory accuracy. To obtain high positioning accuracy based on source limited devices, various AP selection strategies have been proposed to select the most discriminant APs for positioning. In this paper, we propose a spatially localized AP selection method based on joint location information gain. In contrast to traditional AP selection methods which measure the discriminant ability of APs independently, we consider choosing APs jointly. By considering the correlation of the discriminant ability between different APs, more accurate measure of the discriminant ability of APs can be taken. Furthermore, since the optimal AP selection solution varies spatially, we incorporate a location clustering method to localize AP selection and subsequent positioning process. Finally, support vector regression (SVR) algorithm is combined to estimate the location. Experiments are carried in a realistic Wi-Fi indoor environment. Experimental results show that, by using the localized joint AP selection strategy, the proposed positioning method achieves a high-level accuracy while reducing the energy consumption on client devices significantly.

A new protocol for concurrently allocating licensed spectrum to underlay cognitive users

Cognitive radio technology makes efficient use of the valuable radio frequency spectrum in a non-interfering manner to solve the problem of spectrum scarcity. This paper aims to design a scheme for the concurrent use of licensed frequencies by Underlay Cognitive Users （UCUs）. We develop a new receiver-initiated Medium Access Control （MAC） protocol to facilitate the selections of alternative reliable carrier frequencies. A circuit is designed to establish reliable carrier selections based on the Received Signal Strength Indicator （RSSI） at the receiving end. Based on both packet-level simulations and various performance parameters, a comparison is carried out among conventional techniques, including the Multiple Access with Collision Avoidance （MACA） and MACA by invitation（MACA-BI） techniques, and our scheme. The simulated results demonstrate that when conventional techniques are used, the system overhead time increases from 0.5 s on the first attempt to 16.5 s on the sixth attempt. In the proposed scheme under the same failure condition, overhead time varies from 0.5 s to 2 s. This improvement is due to the complete elimination of the exponential waiting time that occurs during failed transmissions. An average efficiency of 60% is achieved with our scheme while only 43% and 34% average efficiencies are achieved with the MACA and MACA-BI techniques, respectively. The throughput performance of our scheme on the fourth attempt is 7 Mbps, whereas for the MACA and MACA-BI protocols, it is 1.9 Mbps and 2.2 Mbps respectively.