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Beacon-Less Geographic Routing in Real Wireless Sensor Networks

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Journal of Computer Science & Technology 2008年第3期23卷 438-450页

作者： Juan A.Sánchez Rafael Marín-Pérez Pedro M.Ruiz department of Information and communications Engineering University of MurciaSpain

Geographic Routing （GR） algorithms require nodes to periodically transmit HELLO messages to allow neighbors to know their positions （beaconing mechanism）. Beacon-less routing algorithms have recently been proposed to reduce the control overheads due to these messages. However, existing beacon-less algorithms have not considered realistic physical layers. Therefore, those algorithms cannot work properly in realistic scenarios. In this paper we present a new beacon-less routing protocol called BOSS. Its design is based on the conclusions of our open-field experiments using Tmote-sky sensors. BOSS is adapted to error-prone networks and incorporates a new mechanism to reduce collisions and duplicate messages produced during the selection of the next forwarder node. We compare BOSS with Beacon-Less Routing （BLR） and Contention-Based Forwarding （CBF） algorithms through extensive simulations. The results show that our scheme is able to *** almost perfect packet delivery ratio （like BLR） while having a low bandwidth consumption （even lower than CBF）. Additionally, we carried out an empirical evaluation in a real testbed that shows the correctness of our simulation results.

关键词： geographic routing beacon-less forwarding performance evaluation real deployment

Efficient nonlinear companding scheme for substantial reduction in peak-to-average power ratio of OFDM

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Journal of Systems Engineering and Electronics 2015年第5期26卷 924-931页

作者： Kasun Bandara Atul Sewaiwar Yeon-Ho Chung department of Information and communications Engineering Pukyong National University

Orthogonal frequency division multiplexing(OFDM)produces a high peak-to-average power ratio(PAPR) that adversely affects high-speed OFDM data transmission. In order to reduce the high PAPR, an efficient nonlinear companding transform(NCT) function is proposed. With the proposed NCT function,the compression and expansion weights can be applied independently with suitably chosen function parameter values. As a result, the proposed function can easily maintain the average signal power approximately unchanged during the companding *** this regard, the proposed function is superior to previously proposed schemes. Also, the simulations show the outstanding PAPR reduction performance of the proposed function. It is demonstrated that the proposed scheme performs well with nonlinear transmitter amplifiers and delivers superior error performance, compared with error function and exponential function based schemes.

关键词： companding orthogonal frequency division multiplexing(OFDM) peak-to-average power ratio(PAPR)

Power Reallocation and Complexity Enhancement for Beyond 4G Systems

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China communications 2019年第6期16卷 114-128页

作者： Omar Daoud communications and Electronics Engineering department Philadelphia University

Competitiveness in the modern wireless systems’provided services is a key factor in the development,in addition to the adaptation to/harmonization of user ***,this paper discussed the quality of services from the point of view of the need for supporting the needed data *** this purpose,a benchmark based on Multi-Antenna Multiband Orthogonal Frequency Division Multiplexing has been proposed to compatible with Ultra-Wideband systems such as the fifth generation based *** order to enhance the system quality of service,the structure of the ultra-wideband system’s main stage;namely Orthogonal Frequency Division Multiplexing has been modified by imposing a low complexity designed Haar-wavelets stage instead of the fast Fourier transform *** is in addition to reallocate the transmitted power in order to reduce the effect of one of the main drawbacks that is found in the Orthogonal Frequency Division Multiplexing;namely the peak-to-average power ratio problem.A MATLAB simulation has been performed in order to validate the propositions that have been made based on six different performance *** a result,the new propositions were achieved our targets by reducing the system’s complexity in terms of mathematical operations and by giving promising results in managing the transmitted ***,the effectiveness of such work has been verified and compared with four different work in the literature。

关键词： multi antennas-multiband wireless PAPR Haar-DWT power reallocation ACLR EVM

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Journal of Systems Science & Complexity 2019年第3期32卷 737-758页

作者： BERAHMAND Kamal BOUYER Asgarali department of Information Technology and communications Azarbaijan Shahid Madani University

Community structure is one of the most best-known proper ties of complex networks. Finding communities help us analyze networks from a mesoscopic viewpoints instead of microscopic or macroscopic one. It helps to understand behavior grouping. Various community detection algorithms have been proposed with some shortcomings in time and space complexity, accuracy, or stability. Label Propagation Algorithm (LPA) is a popular method used for finding communities in an almost-linear time-consuming process. However, its performance is not satisfactory in some metrics such as accuracy and stability. In this paper, a new modified version of LPA is proposed to improve the stability and accuracy of the LPA by defining two concepts -nodes and link strength based on semi-local similarity-, while preserving its simplicity. In the proposed method a new initial node selection strategy, namely the tiebreak strategy, updating order and rule update are presented to solve the random behavior problem of original LPA. The proposed algorithm is evaluated on artificial and real networks. The experiments show that the proposed algorithm is close to linear time complexity with better accuracy than the original LPA and other compared met hods. Furthermore, the proposed algorithm has the robustness and stability advantages while the original LPA does not have these features.

关键词： Community detection complex networks LPA similarity measure

Improving the reconstruction efficiency of sparsity adaptive matching pursuit based on the Wilkinson matrix

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Frontiers of Information Technology & Electronic Engineering 2018年第4期19卷 503-512页

作者： Rasha SHOITAN Zaki NOSSAIR I.I.IBRAHIM Ahmed TOBAL Computer and Systems department Electronic Research Institute Electronics Communicationsand Computer DepartmentHelwan University

Sparsity adaptive matching pursuit(SAMP)is a greedy reconstruction algorithm for compressive sensing *** reconstructs signals without prior information of sparsity and presents better reconstruction performance for noisy signals compared to other greedy ***,SAMP still suffers from relatively poor reconstruction quality especially at high compression *** the proposed research,the Wilkinson matrix is used as a sensing matrix to improve the reconstruction quality and to increase the compression ratio of the SAMP ***,the idea of block compressive sensing(BCS)is combined with the SAMP technique to improve the performance of the SAMP *** simulations have been conducted to evaluate the proposed BCS-SAMP technique and to compare its results with those of several compressed sensing *** results show that the proposed BCS-SAMP technique improves the reconstruction quality by up to six decibels(d B)relative to the conventional SAMP *** addition,the reconstruction quality of the proposed BCS-SAMP is highly comparable to that of iterative ***,the computation time of the proposed BCS-SAMP is less than that of the iterative techniques,especially at lower measurement fractions.

关键词： Block compressive sensing Sparsity adaptive matching pursuit Greedy algorithm Wilkinson matrix

Rolling shutter aided optical camera communications with increasing communication distance

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Optoelectronics Letters 2019年第5期15卷 363-367页

作者： LI Te-yu CHI Xue-fen SHI Han-yang SUN Hong-liang WANG Shuang department of communications Engineering Jilin University

Although optical camera communication(OCC) is gaining increasing attention in research, developing a practical OCC system to increase data rate and transmission distance is still an issue. The rolling shutter can increase data rate, but it also limits the transmission distance at the same time. When the transmission distance is long, the thresholding method will become difficult and the block sequence number(BSN) is easy to be wrong due to bit errors, which will make it impossible to reorder the frame sequences. In this paper, in order to increase the transmission distance, we propose the efficient thresholding method which transforms partial mean gray values of per column nonlinearly to increase the contrast between light and dark bands. In addition, this method takes the frame image of the camera as the basic unit to adjust the threshold for the environment in which each frame of the image is located. Experimental results show that this method is better than the polynomial regression. Moreover, we perform the error correction of BSN by using its continuity to specify the legal BSNs and the illegal BSNs.

关键词： optical camera communication(OCC) block sequence number(BSN) Rolling shutter

A new approach for modeling of dark current characteris-tics of quantum wire infrared photodetectors

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Optoelectronics Letters 2011年第4期7卷 260-262页

作者： H.Barickaby A.Zarifkar M.H.Sheikhi department of communications and Electronics Shiraz University

In order to study the dark current characteristics in a quantum wire infrared photodetector(QRIP),the average number of electrons in quantum wires(QRs) must be got,which is mostly too *** this paper we give a simple formula to calculate the average number of carriers in a quantum wire(QR) that can be easily evaluated by mathematical softwares,and then we use this formula to study dark current characteristics of a quantum wire infrared photodetector(QRIP).

关键词：暗电流特性红外探测器量子线建模软件评估平均数 QRS 运营商

Energy Efficiency and Latency Analysis of Fog Networks

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China communications 2020年第4期17卷 66-77页

作者： Raad S.Alhumaima department of communications College of EngineeringUniversity of DiyalaDiyalaIraq

The industry of cellular networks is evaluating the new architectures to ensure an enhanced performance. Fog communication is the new paradigm that presented to unleash edge computing. In this paper, we introduced a mathematical framework to evaluate the trade-offs of Fog proposal. Specifically, testing the power consumption, delay and energy efficiency in comparison with traditional cloud radio access networks. Although the literature has showed that fog radio access networks provides an enhanced delay performance, this paper shows that an enlarged amount of power is consumed, which degrades the energy efficiency in comparison with traditional cloud counterpart. However, the level of such devolution depends on the number of deployed fog devices that directly influences the power consumption. This paper also shows that enhancing the delay by using fog architecture is not a straight forward process, but requires a particular caring in terms of choosing the appropriate mode while placing/installing fog functions within fog devices.

关键词： fog communications cloud networks models modelling power energy efficiency delay

Color image encryption scheme based on chaotic systems

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The Journal of China Universities of Posts and Telecommunications 2018年第2期25卷 39-48页

作者： Min Xiangshen Fan Jiulun Zhang Xuefeng Ren Fang department of communications and Information Engineering Xi'an University of Posts and Telecommunications

To improve the security of the color image encryption scheme,a color image encryption scheme based on chaotic systems is proposed. Firstly, the proposed scheme sets the color image as a three-dimensional matrix which is scrambled by affine transformation. Second, the Logistic chaotic sequence applied to generate the control parameter and auxiliary key is used to encrypt the three-dimensionaL matrix. Here, we mainly focus on two methods for encryption processes. One is to generate a chaotic sequence by Logistic map and Henon map, which is used to perform XOR operation with the scrambled components R＇, G＇, B＇ respectively. The other one is to adopt a binary Logistic sequence to select the pixel position for the scrambled components R＇, G＇, B＇ image, and then applying the Henon map and Logistic map with the auxiliary key to perform the replacement encryption. Based on this, an encrypted image is synthesized. Simulation results show that the proposed image encryption scheme can implement better encryption and achieve higher security performance.

关键词： color image cncryption chaotic systems affine transformation Logistic map Henon map security performance