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  • Multiple transmit antennas for low PAPR spatial modulation in SC-FDMA: single vs. multiple streams
    EURASIP J. Wirel. Commun. Netw. (IF 1.592) Pub Date : 2020-02-19
    Darko Sinanović, Gordan Šišul, Adrian Satja Kurdija, Željko Ilić

    Abstract The main reason for the selection of single-carrier frequency division multiple access (SC-FDMA) modulation technique in mobile high data rate communications lays in its low value of peak-to-average power ratio (PAPR). If spatial modulation, a multiple-input multiple-output technique that achieves bitrate increase, is applied to the SC-FDMA system in its conventional form, the PAPR level is increased. Hence, based on previously mentioned, in this paper, we provide the general design criteria for low PAPR spatial modulation (LPSM) implemented in SC-FDMA systems with multiple transmit antennas. The straightforward generalization of LPSM is derived and it is shown that it requires the number of transmit antennas to be doubled in order to add another bit in the spatial component. Based on that, the alternative generalized technique with higher number of spatial bits is proposed. As these techniques present single-stream generalizations, the approach with multiple-streams is proposed as well. After PAPR and performance comparisons, it is concluded that single-stream techniques outperform multiple-stream techniques in the cases of low overall data rate, whereas multiple-stream approach is better in high overall data rate scenarios. All proposed techniques maintain low PAPR level on all transmit antennas.

    更新日期:2020-02-19
  • Periodicity makes perfect: recovering interfered preamble for high-coexistence wireless systems
    EURASIP J. Wirel. Commun. Netw. (IF 1.592) Pub Date : 2020-02-19
    Ping Li, Panlong Yang, Yubo Yan

    Abstract Recent researches show that cross technology interference management plays an important role in the emergence of innovative applications for nowadays wireless networks. Existing algorithms either suffer from the constraint on the need of clean preamble or require technological similarities among cross technology systems. In this paper, we ask the question: “whether the packet with interfered preamble can be decoded?" To answer this question, we investigate the property of preamble and propose Narthil, an innovative coexistence algorithm which based on imperfect interference management, handling packet detection, symbol synchronization, and channel estimation with interfered preambles. Narthil applies a simple Butterworth band-stop filter for imperfect interference filtering, and leverages the residual signals for packet detection and symbol synchronization, as well as channel estimation. The insight is the inherent properties of preamble such as periodicity and modulation scheme, and the frequency continuity in OFDM signal could be effectively leveraged for important processes such as packet detection, symbol synchronization, and channel estimation. These favorable properties could be used to further enhance the performance of other cross technology signal coexistence algorithms. We implement Narthil algorithm on our USRP/GNU Radio platform, and evaluate its performance by using 15 USRP-N210 devices through the real deployment experiments. The results demonstrate that Narthil can effectively detect the incoming packet and achieves a high accuracy symbol synchronization, as well as channel estimation of the interfered preamble, and also achieve a good performance on packet decoding.

    更新日期:2020-02-19
  • Time series classification based on statistical features
    EURASIP J. Wirel. Commun. Netw. (IF 1.592) Pub Date : 2020-02-19
    Yuxia Lei, Zhongqiang Wu

    Abstract This paper presents a statistical feature approach in fully convolutional time series classification (TSC), which is aimed at improving the accuracy and efficiency of TSC. This method is based on fully convolutional neural networks (FCN), and there are the following two properties: statistical features in data preprocessing and fine-tuning strategies in network training. The key steps are described as follows: firstly, by the window slicing principle, dividing the original time series into multiple equal-length subsequences; secondly, by extracting statistical features on each subsequence, in order to form a new sequence as the input of the neural network, and training neural network by the fine-tuning idea; thirdly, by evaluating the classification performance about test sets; and finally, by comparing the sample sequence complexity and network classification loss accuracy with the FCN using the original sequence. Our experimental results show that the proposed method improved the classification effects of FCN and the residual network (ResNet), which means that it has a generalization ability to the network structures.

    更新日期:2020-02-19
  • Correction to: TDOA versus ATDOA for wide area multilateration system
    EURASIP J. Wirel. Commun. Netw. (IF 1.592) Pub Date : 2020-02-18
    Daniel Frisch, Uwe D. Hanebeck

    Abstract The paper (Stefanski and Sadowski, EURASIP J. Wirel. Commun. Netw. 2018, Article 179) introduces a multilateration algorithm for unsynchronized sensor networks. However, a very similar method has been proposed before that is not cited. Furthermore, in the measurement model of Stefanski and Sadowski (EURASIP J. Wirel. Commun. Netw. 2018, Article 179), an incorrect covariance matrix (Eq. (11) in Stefanski and Sadowski (EURASIP J. Wirel. Commun. Netw. 2018, Article 179)) has been used that leads to inferior results. We summarize the context and explain the measurement methodology proposed in Stefanski and Sadowski (EURASIP J. Wirel. Commun. Netw. 2018, Article 179), while referring to the missing citation. Finally, we derive the correct covariance matrix of the measurement error and demonstrate that the covariance matrix proposed in Stefanski and Sadowski (EURASIP J. Wirel. Commun. Netw. 2018, Article 179) is incorrect.

    更新日期:2020-02-19
  • Control strategy for networked control systems with time delay and packet dropout using linear matrix inequalities
    EURASIP J. Wirel. Commun. Netw. (IF 1.592) Pub Date : 2020-02-14
    Zhaohong Wang, Seiji Fukushima

    Abstract A control strategy using linear matrix inequalities towards time delay and stochastic packet dropout of networked control system is proposed in this paper. First, a reconfigured target plant of networked control system is built based on a linear time-invariant target. Before discretization of target plant, a Pade approximation is employed towards the time delay segment of reconfigured target plant, while zero-order holder compensator and an estimator are employed for packet dropout of control input and measured output, respectively. Then the control target is reformed as a programming problem of an uncertain time-variant multi-parametric state space. In order to deal with such problem, herein the time-variant state space is rewritten as a linear parametric-varying prediction model by enumerating all possible occasions. Afterwards, a novel robust model predictive controller is proposed as a constrained minimax optimization of the predictive cost function. Finally, we present two simulations based on an aircraft model and a second-order numeric model, by which step responses and explicit solutions are derived, performed and analysed. Simulation results demonstrate both the stability and robustness of the proposed control strategy.

    更新日期:2020-02-14
  • Inter-domain resource optimization method of software-defined multi-domain optical network
    EURASIP J. Wirel. Commun. Netw. (IF 1.592) Pub Date : 2020-02-13
    Zikang Li, Changming Yang, Zhenrong Zhang, Sifeng Hu

    Abstract In practical application scenarios, the division of different operators or the same operator in different regions constitutes a natural network region, forming a multi-domain optical network. At the beginning, this paper introduces the hierarchical architecture of software-defined optical network (SDON) and the functional model of control plane. Then, it describes a control system of software-defined multi-domain optical network based on hierarchical control mode and briefly analyzes their basic functional model. In the end, around the problems of resource allocation between scenarios in multi-domain optical network, this paper respectively analyzes the optimization of routing resources in inter-domain and the mechanism of spectrum defragmentation. At the same time, it separately simulates the resource optimization algorithms of single control architecture and hierarchical control architecture to verify the superiority of hierarchical control system.

    更新日期:2020-02-13
  • Edge caching strategy design and reward contract optimization for uAV-enabled mobile edge networks
    EURASIP J. Wirel. Commun. Netw. (IF 1.592) Pub Date : 2020-02-10
    Weidang Lu, Bin Yin, Guoxiang Huang, Bo Li

    Abstract Edge caching is a promising technology to alleviate the burden on backhaul and improve the quality of experience (QoE) of users in unmanned aerial vehicle (UAV)-enabled mobile edge networks, which has played an important role in wireless communication systems. However, owing to the selfish nature and limited battery life of the user equipments (UEs), only a limited part of the caching resources will be shared by the UEs. To drive the UEs to share more caching resources to improve the social welfare of the UAV-enabled mobile edge network, in this paper, we jointly design an edge caching strategy and reward contract optimization scheme. Aiming to maximize the utility of the UAV, a joint edge caching and contract optimization problem is formulated. Firstly, a novel edge caching strategy is proposed based on the content popularity. Then, an optimal reward contract is designed by reducing the restrictions. Finally, the system performance of the designed caching strategy and reward contract is evaluated compared with two benchmark caching schemes with no incentives. Simulation results show that the proposed scheme performs better than the other two schemes in terms of the utilities of the UAV and UEs, which proves the efficiency of our proposed scheme.

    更新日期:2020-02-10
  • Thunderstorm identification algorithm research based on simulated airborne weather radar reflectivity data
    EURASIP J. Wirel. Commun. Netw. (IF 1.592) Pub Date : 2020-02-10
    Xu Wang, Rui Liao, Jing Li, Jianxin He, Guoqiang Wang, Zili Xu, Haijiang Wang

    Abstract In the past few decades, radar reflectivity data have been widely used in thunderstorm identification research. Many thunderstorm identification algorithms for ground-based weather radar have been developed. But for airborne weather radar, due to the relative scarcity of data, the thunderstorm identification research is insufficient and there are still few effective identification methods. Airborne weather radar has the realization capability of close-range detection, but most existing airborne weather radars do not have scanning capability. This paper proposes an airborne weather radar volume scan mode, under which there is a total of 31 sector scans at 31 elevations in a volume scan. And a reflectivity data simulation model of the airborne weather radar is established based on this scan strategy, then the ground-based X-band radar reflectivity data are used as input to obtain the simulated X-band airborne radar reflectivity data. Moreover, this paper studies a thunderstorm identification algorithm for the X-band airborne radar with the proposed scan mode. An improved SCI (storm cell identification) algorithm is proposed on the basis of the traditional SCI algorithm which is applicable to S-band ground-based weather radar. The results of thunderstorm identification carried out on the simulated airborne radar data show that the algorithm can effectively identify the thunderstorm cells in the mature stage and the developing stage.

    更新日期:2020-02-10
  • Features extraction and analysis for device-free human activity recognition based on channel statement information in b5G wireless communications
    EURASIP J. Wirel. Commun. Netw. (IF 1.592) Pub Date : 2020-02-05
    Hui Yuan, Xiaolong Yang, Ailin He, Zhaoyu Li, Zhenya Zhang, Zengshan Tian

    Abstract Features extraction and analysis for human activity recognition (HAR) have been studied for decades in the 5th generation (5G) and beyond the 5th generation (B5G) era. Nowadays, with the extensive use of unmanned aerial vehicles (UAVs) in the civil field, integrating wireless signal receivers on UAVs could be a better choice to receive hearable signals more conveniently. In recent years, the HAR system based on CSI based on WiFi radar has received widespread attention due to its low cost and privacy protection property. However, in the existing CSI-based HAR system, there are two disadvantages: (1) The detection threshold is manually set, which limits its adaptability and immediacy in different wireless environments. (2) A sole classifier is used to complete the recognition, resulting in poor robustness and relatively low recognition accuracy. In this paper, we propose a CSI-based device-free HAR (CDHAR) system with WiFi-sensing radar integrated on UAVs to recognize everyday human activities. Firstly, by using machine learning, CDHAR applies kernel density estimation (KDE) to obtain adaptive detection thresholds to complete the extraction of activity duration. Second, we proposed a random subspace classifier ensemble method for classification, which applies the frequency domain feature instead of the time domain feature, and we choose each kind of feature in the same amount. Finally, we prototype CDHAR on commercial WiFi devices and evaluate its performance in both indoor environment and outdoor environments. The experiment results tell that even if experimental scenario varies, the accuracy of activity durations extraction can reach 98% and 99.60% whether in outdoor or indoor environments. According to the extracted data, the recognition accuracy in outdoor and indoor environments can reach 91.2% and 90.2%, respectively. CDHAR ensures high recognition accuracy while improving the adaptability and instantaneity.

    更新日期:2020-02-06
  • Energy-efficient offloading decision-making for mobile edge computing in vehicular networks
    EURASIP J. Wirel. Commun. Netw. (IF 1.592) Pub Date : 2020-02-05
    Xiaoge Huang, Ke Xu, Chenbin Lai, Qianbin Chen, Jie Zhang

    Abstract Driven by the explosion transmission and computation requirement in 5G vehicular networks, mobile edge computing (MEC) attracts more attention than centralized cloud computing. The advantage of MEC is to provide a large amount of computation and storage resources to the edge of networks so as to offload computation-intensive and delay-sensitive applications from vehicle terminals. However, according to the mobility of vehicle terminals and the time varying traffic load, the optimal task offloading decisions is crucial. In this paper, we consider the uplink transmission from vehicles to road side units in the vehicular network. A dynamic task offloading decision for flexible subtasks is proposed to minimize the utility, which includes energy consumption and packet drop rate. Furthermore, a computation resource allocation scheme is introduced to allocate the computation resources of MEC server due to the differences in the computation intensity and the transmission queue of each vehicle. Consequently, a Lyapunov-based dynamic offloading decision algorithm is proposed, which combines the dynamic task offloading decision and computation resource allocation, to minimize the utility function while ensuring the stability of the queue. Finally, simulation results demonstrate that the proposed algorithm could achieve a significant improvement in the utility of vehicular networks compared with comparison algorithms.

    更新日期:2020-02-06
  • Fast matrix inversion methods based on Chebyshev and Newton iterations for zero forcing precoding in massive MIMO systems
    EURASIP J. Wirel. Commun. Netw. (IF 1.592) Pub Date : 2020-02-04
    Sherief Hashima, Osamu Muta

    Abstract In massive MIMO (mMIMO) systems, large matrix inversion is a challenging problem due to the huge volume of users and antennas. Neumann series (NS) and successive over relaxation (SOR) are two typical methods that solve such a problem in linear precoding. NS expands the inverse of a matrix into a series of matrix vector multiplications, while SOR deals with the same problem as a system of linear equations and iteratively solves it. However, the required complexities for both methods are still high. In this paper, four new joint methods are presented to achieve faster convergence and lower complexity in matrix inversion to determine linear precoding weights for mMIMO systems, where both Chebyshev iteration (ChebI) and Newton iteration (NI) are investigated separately to speed up the convergence of NS and SOR. Firstly, joint Chebyshev and NS method (ChebI-NS) is proposed not only to accelerate the convergence in NS but also to achieve more accurate inversion. Secondly, new SOR-based approximate matrix inversion (SOR-AMI) is proposed to achieve a direct simplified matrix inversion with similar convergence characteristics to the conventional SOR. Finally, two improved SOR-AMI methods, NI-SOR-AMI and ChebI-SOR-AMI, are investigated for further convergence acceleration, where NI and ChebI approaches are combined with the SOR-AMI, respectively. These four proposed inversion methods provide near optimal bit error rate (BER) performance of zero forcing (ZF) case under uncorrelated and correlated mMIMO channel conditions. Simulation results verify that the proposed ChebI-NS has the highest convergence rate compared to the conventional NS with similar complexity. Similarly, ChebI-SOR-AMI and NI-SOR-AMI achieve faster convergence than the conventional SOR method. The order of the proposed methods according to the convergence speed are ChebI-SOR-AMI, NI-SOR-AMI, SOR-AMI, then ChebI-NS, respectively. ChebI-NS has a low convergence because NS has lower convergence than SOR. Although ChebI-SOR-AMI has the fastest convergence rate, NI-SOR-AMI is preferable than ChebI-SOR-AMI due to its lower complexity and close inversion result.

    更新日期:2020-02-04
  • Web intrusion detection system combined with feature analysis and SVM optimization
    EURASIP J. Wirel. Commun. Netw. (IF 1.592) Pub Date : 2020-02-03
    Chao Liu, Jing Yang, Jinqiu Wu

    Abstract The current network traffic is large, and the network attacks have multiple types. Therefore, anomaly detection model combined with machine learning is developing rapidly. Frequent occurrences of Web Application Firewall (WAF) bypass attacks and the redundancy of the data characteristics in Hypertext Transfer Protocol (HTTP) protocol make it difficult to extract data characteristics. In this paper, an integrated web intrusion detection system combined with feature analysis and support vector machine (SVM) optimization is proposed. By using expert’s knowledge, the characteristics of the common Web attacks are analyzed. The related data characteristics are selected by the analysis of the HTTP protocol. In the classification learning, the mature and robust support vector machine algorithm is utilized and the grid search method is used for the parameter optimization. Consequently, a better detection capability on Web attacks can be obtained. By using the HTTP DATASET CSIC 2010 data set, experiments have been carried out to compare the detection capability of different kernel functions. The results show that the proposed system performs good in the detection capability and can detect the WAF bypass attacks effectively.

    更新日期:2020-02-03
  • EQSM-based multiuser MIMO downlink transmission for correlated fading channels
    EURASIP J. Wirel. Commun. Netw. (IF 1.592) Pub Date : 2020-01-31
    Francisco R. Castillo-Soria, Carlos A. Gutierrez, Abel García-Barrientos, Armando Arce-Casas, Jorge Simón

    Abstract This paper presents three multiuser multiple input-multiple output (MU-MIMO) downlink transmission strategies based on the extended quadrature spatial modulation (EQSM) system for mobile communication. The three MU-MIMO precoding strategies utilised are block diagonalisation (BD), dirty paper coding (DPC), and a combined BD-DPC strategy. We analyse and compare the performance of these three MU-MIMO-EQSM schemes with the conventional MU-MIMO spatial multiplexing (MU-MIMO-SMux) system in terms of bit error rate (BER) and detection complexity considering correlated and uncorrelated fading channels. Results show that the BD-MIMO-EQSM and DPC-MIMO-EQSM systems outperform by 2−3 dB in BER performance their conventional counterparts with the additional advantage of a detection complexity reduction of up to 62% for the analysed cases. For the uncorrelated fading channel, the BD technique has better BER performance for a spectral efficiency (SE) of 12 bits per channel use (bpcu), while the DPC technique has better BER performance for an SE of 8 bpcu. Considering the correlated channel, DPC suffers a deep BER degradation of up to 30 dB compared with BD. However, still in this scenario, both proposed MU-MIMO-EQSM systems outperform their conventional counterparts. In terms of detection complexity, DPC has a complexity reduction of 77% as compared with the BD technique. The BD-DPC-MIMO-EQSM hybrid system heritages the low detection complexity of DPC with the advantage of all users in the system having the same BER performance.

    更新日期:2020-01-31
  • Modeling of Real Time Kinematics localization error for use in 5G networks
    EURASIP J. Wirel. Commun. Netw. (IF 1.592) Pub Date : 2020-01-31
    Marcin Hoffmann, Paweł Kryszkiewicz, Georgios P. Koudouridis

    Abstract In 5G networks information about localization of a user equipment (UE) can be used not only for emergency calls or location-based services, but also for the network optimization applications, e.g., network management or dynamic spectrum access by using Radio Environment Maps (REM). However, some of these applications require much better localization accuracy than currently available in 4G systems. One promising localization method is Global Navigation Satellite System (GNSS)-based Real-Time Kinematics (RTK). While the signal received from satellites is the same as in traditional GNSS, a new reception method utilizing real-time data from a nearby reference station (e.g., 5G base station) results in cm-level positioning accuracy. The aim of this paper is to obtain a model of the RTK localization error for smartphone-grade GNSS antenna under open-sky conditions, that can be used in 5G network simulators. First, a tutorial-style overview of RTK positioning, and satellite orbits prediction is provided. Next, an RTK localization simulator is implemented utilizing GNSS satellites constellations. Results are investigated statistically to provide a simple, yet accurate RTK localization error framework, which is based on two Gauss-Markov process generators parametrized by visible satellites geometry, UE motion, and UE-satellite distance error variance.

    更新日期:2020-01-31
  • The energy-efficient MDA-SMAC protocol for wireless sensor networks
    EURASIP J. Wirel. Commun. Netw. (IF 1.592) Pub Date : 2020-01-31
    Ke Wang, Xiaohu Zhao, Yao Shi, Donghong Xu, Ruoyu Li

    Abstract Nodes in original S-MAC protocol just can visit the channel in the scheduling and listening stage. The working schema may result in data latency and high conflict. To solve those above problems, we split scheduling duty into multiple micro-duties. By using different micro-dispersed contention channel, the sensor nodes reduce the collision probability of the data. Aiming at detecting the fixed duty cycle in S-MAC protocol, on the basis of the micro-duty and buffer queue length, this paper presents an adaptive duty cycle and back-off algorithm. While using different back-off algorithm with different duty cycles, sensor node Fast-Binary Exponential Backoff and Conflict-Avoid-Binary exponential Backoff algorithm separated are applied to reduce data latency further reduce the conflict probability. Combining both of the improvements, we propose a modified S-MAC protocol. Comparing the performance of S-MAC protocol and Division-Multiple Access-Media Access Control (MDA-SMAC) protocol on the NS-2 simulation platform, the results show that MDA-SMAC protocol performs better in terms of energy consumption, latency, and effective throughput than S-MAC protocol

    更新日期:2020-01-31
  • Correction to: On Gaussian covert communication in continuous time
    EURASIP J. Wirel. Commun. Netw. (IF 1.592) Pub Date : 2020-01-30
    Ligong Wang

    Following publication of the original article [1], the authors flagged that the article had published with an error in one of the equations (Eq. 46), in addition to a few minor formatting errors (concerning spacing and parentheses).

    更新日期:2020-01-31
  • Design and implementation of intelligent accounting data analysis platform based on industrial cloud computing
    EURASIP J. Wirel. Commun. Netw. (IF 1.592) Pub Date : 2020-01-29
    Wang Ting, Yang Liu

    Abstract In order to improve the ability of accounting data analysis and statistics, a method of constructing modern accounting data analysis platform based on industrial cloud computing is proposed. The time series model of modern accounting data analysis is constructed by using block bit sequence analysis method, and the association rule characteristic quantity of accounting data is extracted. Combined with cloud computing technology, the modern accounting data analysis platform is constructed, and the fuzzy C-means clustering algorithm is used to realize the clustering of modern accounting data, which can improve the ability of parallel computing and statistical analysis of accounting data. The simulation results show that the intelligent data analysis platform designed makes the statistical analysis ability of accounting data better and the parallel computing efficiency higher.

    更新日期:2020-01-30
  • Research on new college Chinese teaching strategy based on SNS network platform and improved particle swarm optimization
    EURASIP J. Wirel. Commun. Netw. (IF 1.592) Pub Date : 2020-01-29
    Xun Bian, Zhang Chaomin, Jinwen Zhao

    Abstract With the rapid development of network technology, college Chinese teaching needs to be reformed as so to adapt to the network environment. This paper puts forward a new strategy of college Chinese teaching based on SNS (social network services) network platform, constructs the model of college Chinese teaching resource allocation, and designs the college Chinese teaching network teaching platform using SNS network method. The routing nodes of SNS network platform are optimized, and the improved PSO (particle swarm optimization) is used to optimize the location of SNS network platform nodes. Based on the node distribution model of PSO, the node overlay connectivity graph of the new SNS network platform of college Chinese teaching is reconstructed to realize the network coverage optimization. The experimental results show that the proposed SNS network platform has better performance of resource scheduling and network connectivity.

    更新日期:2020-01-30
  • An Unsupervised LLR Estimation with unknown Noise Distribution
    EURASIP J. Wirel. Commun. Netw. (IF 1.592) Pub Date : 2020-01-29
    Yasser Mestrah, Anne Savard, Alban Goupil, Guillaume Gellé, Laurent Clavier

    Abstract Many decoding schemes rely on the log-likelihood ratio (LLR) whose derivation depends on the knowledge of the noise distribution. In dense and heterogeneous network settings, this knowledge can be difficult to obtain from channel outputs. Besides, when interference exhibits an impulsive behavior, the LLR becomes highly non-linear and, consequently, computationally prohibitive. In this paper, we directly estimate the LLR, without relying on the interference plus noise knowledge. We propose to select the LLR in a parametric family of functions, flexible enough to be able to represent many different communication contexts. It allows limiting the number of parameters to be estimated. Furthermore, we propose an unsupervised estimation approach, avoiding the need of a training sequence. Our estimation method is shown to be efficient in large variety of noises and the receiver exhibits a near-optimal performance.

    更新日期:2020-01-30
  • Band Steering Technology Based on QoE-Oriented Optimization in Wireless Network
    EURASIP J. Wirel. Commun. Netw. (IF 1.592) Pub Date : 2020-01-28
    Zhifeng Han, Jianxin Liao, Qi Qi, Haifeng Sun, Jingyu Wang

    Abstract In mobile crowd-sensing (MCS) network, it is necessary to reduce the cost of sensing data transformation from mobile devices to the MCS platform in the core of the network. With the widespread deployment of access point (AP), explosive data traffic of the mobile devices is offloaded from cellular base stations to Wi-Fi networks. The congestion of the 2.4 GHz band in dual-band wireless area network makes the lower quality of experience (QoE) of users. To ease the load of 2.4 GHz band, the band-steering technology has been widely used by equipment manufacturers. However, the fixed threshold configuration strategy in band steering technology makes it easy to be exploited by setting up a great number of connection requirements in a short time, which may prevent a normal connection requirement of a user, making it difficult to satisfy the dynamic resource requirements of different services. Moreover, if the threshold is configured too high, it may result in QoE imbalance in dual bands. Besides, when the band (such as 2.4 GHz) resources cannot meet the terminal requirement, the terminal cannot autonomously switch to another band (such as 5 GHz), and this may result in a very poor QoE of users. In this paper, a secure QoE-oriented wireless network optimization framework is proposed to improve the QoE of users in dual-band network. Firstly, to ensure the overall QoE of network and balancing the QoE between 2.4 GHz and 5 GHz bands, the framework dynamically adjusts the load threshold of the frequency band based on QoE information during the association of a terminal. Secondly, to meet the basic QoE requirement of each user, the framework preferentially switches the terminals with poor QoE to the idle band after users join the network. The experimental results show that the proposed framework can improve the QoE both before and after the terminal accesses the network. Additionally, it enables the better QoE balance in dual bands.

    更新日期:2020-01-30
  • Non-orthogonal multiple access in full-duplex-based coordinated direct and relay transmission (CDRT) system: performance analysis and optimization
    EURASIP J. Wirel. Commun. Netw. (IF 1.592) Pub Date : 2020-01-23
    Aswathi V, Babu A V

    Abstract This paper considers non-orthogonal multiple access (NOMA)-based coordinated direct and relay transmission (CDRT) system, where the base station (BS) directly communicates with the nearby users while it requires the help of a dedicated relay to communicate with the cell-edge users. We derive exact closed form expression for the outage probabilities experienced by the downlink users and the system outage probability of the considered CDRT network with full-duplex relaying (FDR) technique. Further, we derive approximate closed form expressions for the ergodic rates achieved by the users. The channel of all the links experience Nakagami fading distribution and the analysis takes into account the residual interference generated due to the imperfect successive interference cancelation (I-SIC) technique. We provide numerical and simulation results to identify the impact of key system parameters on the outage and ergodic rate performance of the users and the system outage performance. The outage and ergodic rate performance of users in the considered FDR-based NOMA-CDRT system has been observed to be significantly improved compared to a FDR-based OMA (orthogonal multiple access)-CDRT system. It is observed that random selection of NOMA power allocation coefficients at the BS leads to higher outage for the near users compared to the far users. We determine numerical results for the NOMA power allocation coefficient that leads to equal outage performance for both the users. Finally, we derive analytical expression for the optimal power allocation (OPA) coefficient at the BS that minimizes the system outage probability. Through extensive numerical and simulation studies, we establish that OPA can lead to significant reduction of system outage probability compared to random selection of power allocation coefficients at the BS.

    更新日期:2020-01-23
  • A generalized multilevel-hybrid chaotic oscillator for low-cost and power-efficient short-range chaotic communication systems
    EURASIP J. Wirel. Commun. Netw. (IF 1.592) Pub Date : 2020-01-22
    Ammar Dukhan, Dhammika Jayalath, Peter van Heijster, Bouchra Senadji, Jasmine Banks

    Abstract In this paper, we present and evaluate a novel multilevel hybrid-chaotic oscillator. The proposed generalized multilevel-hybrid chaotic oscillator (GM-HCO) was created by combining a multilevel discrete function generated from user data with a continuous function having a damping factor greater than ln(2) to achieve variable rates and adaptive carrier frequencies. Improved spectral efficiency and lower complexity of the transceiver compared with differentially coherent systems were achieved by multilevel signals at the transmitter and a matched filter at the receiver. An exact analytical solution for the generalized fixed basis function and the impulse response of the matched filter were also derived. The bit error rate (BER) expression of the GM-HCO was derived for two levels. It was found that the noise performance of the proposed system was better than a hybrid chaotic system based on forward time and differential chaos shift keying (DCSK). A comprehensive set of simulations were carried out to evaluate the performance of the proposed system with chaotic communication systems in the presence of additive white Gaussian noise (AWGN). The performance of the proposed system was comparable with that of conventional communication systems. The results demonstrate that the proposed system can offer better noise performance than existing chaotic communication systems, and it also offers variable transmitter frequencies and improved spectral efficiency. Noise-like behavior of the chaotic signals provides an additional layer of security at the physical layer compared with conventional (sinusoidal) communication systems.

    更新日期:2020-01-23
  • Information rates of precoding for massive MIMO and base station cooperation in an indoor scenario
    EURASIP J. Wirel. Commun. Netw. (IF 1.592) Pub Date : 2020-01-21
    Stefan Dierks, Gerhard Kramer, Berthold Panzner, Wolfgang Zirwas

    Abstract The performance of centralized and distributed massive MIMO deployments are studied for simulated indoor office scenarios. The distributed deployments use one of the following precoding methods: (1) local precoding with local channel state information (CSI) to the user equipments (UEs) that it serves, (2) large-scale MIMO with local CSI to all UEs in the network, (3) network MIMO with global CSI. For the distributed deployment (3), it is found that using twice as many base station antennas as data streams provides many of the massive MIMO benefits in terms of spectral efficiency and fairness. This is in contrast to the centralized and distributed deployments using (1) or (2) where more antennas are needed. Two main conclusions are that distributing base stations helps to overcome wall penetration loss; however, a backhaul is required to mitigate inter-cell interference. The effect of estimation errors on the performance is also quantified.

    更新日期:2020-01-22
  • Routing protocol for Low-Power and Lossy Networks for heterogeneous traffic network
    EURASIP J. Wirel. Commun. Netw. (IF 1.592) Pub Date : 2020-01-20
    Arslan Musaddiq, Yousaf Bin Zikria, Zulqarnain, Sung Won Kim

    Abstract In a real network deployment, the diverse sensor applications generate a heterogeneous traffic pattern which may include basic sensing measurements such as temperature readings or high-volume multimedia traffic. In a heterogeneous traffic network, the two standardized objective functions (OFs), i.e., objective function zero (OF0) and the Minimum Rank with Hysteresis Objective Function (MRHOF) for routing protocol for Low-Power and Lossy Networks (RPL) perform poor routing decisions by selecting an already congested parent node and cause more re-transmissions across the network. Therefore, careful consideration is required in designing a new OF for heterogeneous traffic scenarios. In this study, we examine the RPL protocol under a heterogeneous traffic pattern and proposed a new protocol based on queue and workload-based condition (QWL-RPL). The aim of the proposed protocol is to achieve a reliable path with better overall performance. The proposed OF model considers the link workload in addition to mapping the congestion status of the node using the packet queue. We implement the proposed routing model in the Contiki operating system (OS) Cooja environment to compare with the existing technique. The simulation results show that QWL-RPL can improve the performance of a heterogeneous traffic network as compared with both OF0 and MRHOF, specifically in terms of the amount of overhead, packets reception ratio (PRR), average delay, and jitter. Final results indicate that on average, there is a 5%–30% improvement in PRR, 25%–45% reduction in overheads, 12%–30% reduction in average delay, and 20%–40% reduction in jitter.

    更新日期:2020-01-21
  • Background perception for correlation filter tracker
    EURASIP J. Wirel. Commun. Netw. (IF 1.592) Pub Date : 2020-01-16
    Yushan Zhang, Jianan Li, Fan Wu, Lingyue Wu, Tingfa Xu

    Abstract Visual object tracking is one of the most fundamental tasks in the field of computer vision, and it has numerous applications in many realms such as public surveillance, human-computer interaction, robotics, etc. Recently, discriminative correlation filter (DCF)-based trackers have achieved promising results in short-term tracking problems. Most of them focus on extracting reliable features from the foreground of input images to construct a robust and informative description of the target. However, it is often ignored that the image background which contains the surrounding context of the target is often similar across consecutive frames and thus can be beneficial to locating the target. In this paper, we propose a background perception regulation term to additionally exploit useful background information of the target. Specifically, invalid description of the target can be avoided when either background or foreground information becomes unreliable by assigning similar importance to both of them. Moreover, a novel model update strategy is further proposed. Instead of updating the model by frame, we introduce an output evaluation score, which serves to supervise the tracking process and select high-confidence results for model update, thus paving a new way to avoid model corruption. Extensive experiments on OTB-100 dataset well demonstrate the effectiveness of the proposed method BPCF, which gets an AUC score of 0.689 and outperforms most of the state-of-the-art.

    更新日期:2020-01-16
  • Energy-efficient privacy-preserving data aggregation protocols based on slicing
    EURASIP J. Wirel. Commun. Netw. (IF 1.592) Pub Date : 2020-01-14
    Xiaowu Liu, Jiguo Yu, Xiaowei Zhang, Qiang Zhang, Can Fu

    Abstract Wireless sensor networks (WSNs) have become one of the most vigorous techniques in the network domain. However, the sensor nodes of WSNs tend to become the target of attackers due to the broadcast communication mode and the unattended deployment nature. Although it can prevent the sensitive data from being compromised, Slice-Mix-AggRegaTe (SMART) needs to exchange messages frequently in a network, which put tremendous overhead on the sensor nodes with limited resources. Faced with these issues, this paper proposes an energy-efficient privacy-preserving data aggregation protocol based on slicing (EPPA) where a novel slicing mode is adopted to reduce the numbers of slices, which can significantly prevent the data from being compromised and decrease the communication overhead. Meanwhile, an enhanced scheme based on EPPA, called multi-function privacy-preserving data aggregation protocol (MPPA), is presented and it supports multiple functions in the process of data aggregation, such as max/min, count, and mean. The theoretical analysis and the simulation evaluation show that the proposed aggregation protocols demonstrate a better performance in the privacy preserving and the communication efficiency.

    更新日期:2020-01-15
  • Using location semantics to realize personalized road network location privacy protection
    EURASIP J. Wirel. Commun. Netw. (IF 1.592) Pub Date : 2020-01-14
    Li Kuang, Yin Wang, Xiaosen Zheng, Lan Huang, Yu Sheng

    With the rapid development of location-based services in the field of mobile network applications, users enjoy the convenience of location-based services on one side, and they are exposed to the risk of privacy disclosure on the other side. Attackers may attack based on the semantic of the user’s location and user’s query location. A few of existing works on location privacy protection consider to protect the user’s location and his query location simultaneously, while the query location may reflect his requirement. In this paper, based on the existing location privacy protection framework, we first generate sensitive weight documents based on the user’s sensitivity to different location semantics automatically, then obtain the best collaborative segment for k-anonymity of the user’s location by using the reinforcement learning algorithm, and finally, the bidirectional k-disturbance of the user’s location and query location is performed based on the location semantics in real road network environment. The experiment verifies the effectiveness of the proposed method.

    更新日期:2020-01-15
  • An edge computing framework based on OFDM radar for low grazing angle target tracking
    EURASIP J. Wirel. Commun. Netw. (IF 1.592) Pub Date : 2020-01-13
    Vahid Karimi, Reza Mohseni, Mohammad R. Khosravi

    Abstract In this paper, a novel adaptive algorithm to detect and track targets with low grazing angle is addressed. For this purpose, an orthogonal frequency division multiplexing (OFDM) radar signal is employed through an edge computing framework over the radar platform. However, detecting the targets in the low grazing angle area is a great challenge due to severe multipath reflection effects. The Earth’s curvature geometry model is presented as the multipath propagation model. Based on the fact that the different scattering centers of a target resonate at different frequencies, we use the optimized OFDM waveform and propose a novel target tracking procedure for low grazing angle target tracking scenarios. The obtained results show that using an OFDM radar waveform provides a more uniform detection coverage in the presence of multipath propagation such that this will fill in the nulls. Finally, simulations are used to compare the performance of the proposed OFDM waveform with the conventional equal-power, the generalized likelihood ratio (GLR)-based and single-carrier waveforms.

    更新日期:2020-01-14
  • Channel estimation based on the PSS-MUSIC for millimeter-wave MIMO systems equipped with co-prime arrays
    EURASIP J. Wirel. Commun. Netw. (IF 1.592) Pub Date : 2020-01-13
    Shufeng Li, Guangjing Cao, Libiao Jin, Hongda Wu

    The millimeter-wave channel estimation problem can be solved by estimating the path directions and the path gains. The previous schemes are nearly all based on the uniform linear arrays (ULAs). However, compared with the ULAs, the co-prime array can use fewer array elements to realize larger array aperture, which is beneficial to improve the performance of arrival direction estimation contributing to the estimation performance of angle of arrival (AOA) and angle of departures (AOD). Encouraged by the property of co-prime arrays, a novel channel estimation scheme is proposed for two-dimensional (2-d) co-prime arrays. For each path direction, multiple peaks are generated in the spatial spectrum of each subarray and by selecting over any limited sector to search for an arbitrary peak, which can recover the rest peaks. Then by comparing the peaks of the two subarrays, the common peaks are the correct path direction. Compared with the total-spectrum search (TSS) method, this method effectively reduces the complexity. Simulation results show that the proposed algorithm can reduce the computational complexity and maintain accurate channel estimation.

    更新日期:2020-01-14
  • Cache-aided mobile edge computing for B5G wireless communication networks
    EURASIP J. Wirel. Commun. Netw. (IF 1.592) Pub Date : 2020-01-13
    Junjuan Xia, Chao Li, Xiazhi Lai, Shiwei Lai, Fusheng Zhu, Dan Deng, Liseng Fan

    Abstract This paper investigates a cache-aided mobile edge computing (MEC) network, where the source offloads the computation task to multiple destinations with computation capacity, with the help of a cache-aided relay. For the proposed cache-aided MEC networks, two destination selection criteria have been proposed to maximize the computation capacity of the selected destination, the channel gain of relay link and the channel gain of direct link, respectively. Similarly, three destination selection criteria have been proposed for the cache-free MEC networks based on the computation capacities of destinations and the channel gains of transmission links, respectively. To evaluate the system performance regarding the latency constraint, we provide the outage probability for the proposed network which is defined based on the transmission-plus-computation time. Our analysis suggests that caching can significantly alleviate the impact of increasing the size of computation task, since only half of the transmission time of cache-free network is required. However, the cache-aided network can not fully exploit the signal from both direct and relay links, thus the improvement by caching is less significant in the high signal-to-noise ratio (SNR) region, compared with the cache-free network employing the destination with maximal channel gain of direct link. Numerical results are given to validate our analysis.

    更新日期:2020-01-13
  • Full-duplex decode-and-forward relaying with joint relay-antenna selection
    EURASIP J. Wirel. Commun. Netw. (IF 1.592) Pub Date : 2020-01-13
    Mahsa Shirzadian Gilan, Ha H. Nguyen

    Abstract This paper is concerned with wireless relay networks that employ K full-duplex (FD) decode-and-forward relays to help a source to communicate with a destination. Each FD relay is equipped with multiple antennas, some for receiving and some for transmitting. The paper considers joint relay-antenna selection schemes that are based on the instantaneous channel conditions for two cases of antenna configurations, namely fixed antenna configuration (FAC) and adaptive antenna configuration (AAC). Under FAC, the transmit and receive antennas at each relay are fixed, whereas in the case of AAC an antenna at a relay can be configured to be either a transmit or a receive antenna.In addition to equal power allocation between the source and selected relay, a power scaling approach to counteract the effect of residual self-interference is also examined. Closed-form expressions of the outage probability and average capacity are obtained and provide important insights on the system performance. The accuracy of the obtained expressions are corroborated by simulation results. In particular, it is shown that under FAC and without power scaling, the diversity order approaches K as the self-interference (SI) level gets smaller, while it approaches zero whenever the SI level is nonzero and the SNR increases without bound. Under FAC and with power scaling, the diversity order approaches K for any SI level. For the case of AAC and without power scaling, the diversity order approaches 2K for small SI level. When power scaling is applied in AAC, the diversity order approaches 2K at any SI level.

    更新日期:2020-01-13
  • Inter-Edge and Cloud conversion accelerated user-generated content for virtual brand community
    EURASIP J. Wirel. Commun. Netw. (IF 1.592) Pub Date : 2020-01-10
    Mengmeng Song, Yucong Duan, Tianyi Huang, Lougao Zhan

    Web-based enterprises have increasingly begun to build their own virtual brand community on the Cloud. How to encourage Web users to generate Web content in the Web community continuously and permanently has become the focal point. However, few studies have explored that how to drive the motivation of user-generated content (UGC) named self-enhancement (SE) internalized from the perspective of user’s personal characteristics and then enhance the intention of UGC. Even fewer studies have been devoted to drive the motivation of UGC from the perspective of information technology. Based on self-construal (SC) theory, self-determination (SD) theory, and current immersive applications of Edge computing, we proposed to a solution of user-generated content motivation internalized in the virtual brand community implemented through the manipulation of the tradeoff of inter-Edge and Cloud processing. Our survey shows that different types of self-construal (SC) users have different levels of internal motivation for self-enhancement (SE) accomplished through the organization of user characteristics. We build a detailed simulation of the change of time delay, availability, and cost of inter-Edge and Cloud conversion to demonstrate the feasibility of our proposed mechanism of UGC motivation internalized in the virtual brand community in guiding enhancing the intention of UGC in the community in practice.

    更新日期:2020-01-11
  • Bit error rate performance analysis of AC-MAP in multiple input single output wireless relay network
    EURASIP J. Wirel. Commun. Netw. (IF 1.592) Pub Date : 2020-01-09
    Taha A. Khalaf, Hazem Mohammed

    In this paper, we propose a joint decoding scheme called AC-MAP decoder for multiple input single output (MISO) wireless cooperative communication network that consists of single source, single relay, and single destination. The proposed scheme is based on both Alamouti combining (AC) scheme and maximum a posteriori (MAP) decoder and is used to estimate the data at the destination. The AC-MAP decoder is optimal in the sense that it minimizes the end-to-end bit error rate (BER). In order to analyze performance of the proposed decoder, we derive a closed form expression for the upper bound (UB) on the end-to-end error probability. Distances between system nodes, transmit energy, and channel noise and fading effects are considered in the derivation of the UB. Numerical results show that the closed form UB is very tight and it almost coincides with the exact BER results obtained from simulations. Therefore, we use the derived UB expression to study the effects of the relay position on the BER performance and to find the optimal location of the relay node.

    更新日期:2020-01-09
  • Efficient physical layer key generation technique in wireless communications
    EURASIP J. Wirel. Commun. Netw. (IF 1.592) Pub Date : 2020-01-09
    Rushan Lin, Li Xu, He Fang, Chuan Huang

    Abstract Wireless communications between two devices can be protected by secret keys. However, existing key generation schemes suffer from the high bit disagreement rate and low bit generation rate. In this paper, we propose an efficient physical layer key generation scheme by exploring the Received Signal Strength (RSS) of signals. In order to reduce the high mismatch rate of the measurements and to increase the key generation rate, a pair of transmitter and receiver separately apply adaptive quantization algorithm for quantifying the measurements. Then, we implement a randomness extractor to further increase key generation rate and ensure randomness of generated of keys. Several real-world experiments are implemented to verify the effectiveness of the proposed scheme. The results show that compared with the other related schemes, our scheme performs better in bit generation rate, bit disagreement rate, and randomness.

    更新日期:2020-01-09
  • On secure system performance over SISO, MISO and MIMO-NOMA wireless networks equipped a multiple antenna based on TAS protocol
    EURASIP J. Wirel. Commun. Netw. (IF 1.592) Pub Date : 2020-01-09
    Thanh-Nam Tran, Miroslav Voznak

    Abstract This study examined how to improve system performance by equipping multiple antennae at a base station (BS) and all terminal users/mobile devices instead of a single antenna as in previous studies. Experimental investigations based on three NOMA down-link models involved (1) a single-input-single-output (SISO) scenario in which a single antenna was equipped at a BS and for all users, (2) a multi-input-single-output (MISO) scenario in which multiple transmitter antennae were equipped at a BS and a single receiver antenna for all users and (3) a multi-input-multi-output (MIMO) scenario in which multiple transmitter antennae were equipped at a BS and multiple receiver antenna for all users. This study investigated and compared the outage probability (OP) and system throughput assuming all users were over Rayleigh fading channels. The individual scenarios also each had an eavesdropper. Secure system performance of the individual scenarios was therefore also investigated. In order to detect data from superimposed signals, successive interference cancellation (SIC) was deployed for users, taking into account perfect, imperfect and fully imperfect SICs. The results of analysis of users in these three scenarios were obtained in an approximate closed form by using the Gaussian-Chebyshev quadrature method. However, the clearly and accurately presented results obtained using Monte Carlo simulations prove and verify that the MIMO-NOMA scenario equipped with multiple antennae significantly improved system performance.

    更新日期:2020-01-09
  • A driver’s car-following behavior prediction model based on multi-sensors data
    EURASIP J. Wirel. Commun. Netw. (IF 1.592) Pub Date : 2020-01-08
    Hui Wang, Menglu Gu, Shengbo Wu, Chang Wang

    The prerequisite for the effective operation of vehicle collision warning system is that the necessary operation is not implemented. Therefore, the behavior prediction that the driver should perform when the preceding vehicle braking is the key to improve the effectiveness of the warning system. This study was conducted to acquire characteristics in the car-following behavior when confronted by the braking of the preceding vehicle, including the reaction time and operation behavior, and establish a behavior prediction model. A driving experiment on the expressway was conducted using devices, such as millimeter-wave radars and controller area network (CAN) bus data, to acquire 845 segments of car following when the brake lamps of the car ahead are on. Data analysis demonstrates that the mean of time distance of car following, mean of car-following distance, and time-to-collision (TTC) mean are closely related with whether or not the driver slowed the car down. The operation states of the driver were divided into keeping the unchanged state of the degree of accelerator pedal opening, loosening of accelerator pedal without braking, braking, and other special situations with the input variables of car-following distance, speed of driver’s car, relative speed, time distance, and TTC using the support vector machine (SVM) method to build a prediction model for the operation behavior of the driver. The verification result showed that the model predicts driving behavior with an accuracy rate of 80%. It reflects the actual decision-making process of the driver, especially the normal operation of the driver, to loosen the accelerator pedal without braking. This model can help to optimize the algorithm of the rear-end accident warning system and improve intelligent system acceptance.

    更新日期:2020-01-08
  • Classification, positioning, and tracking of drones by HMM using acoustic circular microphone array beamforming
    EURASIP J. Wirel. Commun. Netw. (IF 1.592) Pub Date : 2020-01-08
    Junfeng Guo, Ishtiaq Ahmad, KyungHi Chang

    Abstract This paper addresses issues with monitoring systems that identify and track illegal drones. The development of drone technologies promotes the widespread commercial application of drones. However, the ability of a drone to carry explosives and other destructive materials may pose serious threats to public safety. In order to reduce these threats, we propose an acoustic-based scheme for positioning and tracking of illegal drones. Our proposed scheme has three main focal points. First, we scan the sky with switched beamforming to find sound sources and record the sounds using a microphone array; second, we perform classification with a hidden Markov model (HMM) in order to know whether the sound is a drone or something else. Finally, if the sound source is a drone, we use its recorded sound as a reference signal for tracking based on adaptive beamforming. Simulations are conducted under both ideal conditions (without background noise and interference sounds) and non-ideal conditions (with background noise and interference sounds), and we evaluate the performance when tracking illegal drones.

    更新日期:2020-01-08
  • A new method to solve the problem of facing less learning samples in signal modulation recognition
    EURASIP J. Wirel. Commun. Netw. (IF 1.592) Pub Date : 2020-01-06
    Sibao Fu, Xiaokai Liu

    In machine learning method, the number of training samples is an exceedingly important factor determining the learning system’s robustness. In our previous researches (Liu et al., J. Syst. Eng. Electron. 27.2:333–342, 2016; Liu et al., IET Commun. 11.7:1000–1007, 2017), the extreme learning machines (ELMs) have proven to be an effective and time-saving learning method for pattern classification and the signal modulation recognition. ELMs are utilized to supervised learning issues principally on signal modulation recognition. In this thesis, ELMs are extended for semi-supervised tasks that are based on the manifold regularization, therefore greatly enlarging ELMs’ applicability. This article evolves countermeasures to the less training samples which mitigate the modulation recognition efficacy and demonstrates the robustness of semi-supervised learning for signal classification in AWGN and Rayleigh-fading channels.

    更新日期:2020-01-06
  • Cache-enabled physical-layer secure game against smart uAV-assisted attacks in b5G NOMA networks
    EURASIP J. Wirel. Commun. Netw. (IF 1.592) Pub Date : 2020-01-06
    Chao Li, Zihe Gao, Junjuan Xia, Dan Deng, Liseng Fan

    This paper investigates cache-enabled physical-layer secure communication in a no-orthogonal multiple access (NOMA) network with two users, where an intelligent unmanned aerial vehicle (UAV) is equipped with attack module which can perform as multiple attack modes. We present a power allocation strategy to enhance the transmission security. To this end, we propose an algorithm which can adaptively control the power allocation factor for the source station in NOMA network based on reinforcement learning. The interaction between the source station and UAV is regarded as a dynamic game. In the process of the game, the source station adjusts the power allocation factor appropriately according to the current work mode of the attack module on UAV. To maximize the benefit value, the source station keeps exploring the changing radio environment until the Nash equilibrium (NE) is reached. Moreover, the proof of the NE is given to verify the strategy we proposed is optimal. Simulation results prove the effectiveness of the strategy.

    更新日期:2020-01-06
  • SLA-aware resource scheduling algorithm for cloud storage
    EURASIP J. Wirel. Commun. Netw. (IF 1.592) Pub Date : 2020-01-03
    Yong Wang, Xiaoling Tao, Feng Zhao, Bo Tian, Akshita Maradapu Vera Venkata Sai

    Cloud computing is a novel computing paradigm, which connects plenty of computing resources and storage resources via Internet. Cloud computing provides a number of high-quality services, such as cloud storage, outsourcing computing, and on-demand self-service, which have been widely accepted by the public. In cloud computing, by submitting their tasks to cloud, plenty of applications share huge computation and storage resources. However, how to schedule resource efficiently is a big challenge in cloud computing.In this paper, we propose a SLA-aware resource algorithm to enable cloud storage more efficiently. In our scheme, we take advantage of the back-end node space utilization and I/O throughput comprehensively simultaneously. We compare and contrast the existing scheduling storage policies by implementing those algorithms. The extensive tests show that our algorithm achieves a considerable improvement in terms of violation rate and the number of used hosts.

    更新日期:2020-01-04
  • Entropy clustering-based granular classifiers for network intrusion detection
    EURASIP J. Wirel. Commun. Netw. (IF 1.592) Pub Date : 2020-01-03
    Hui Liu, Gang Hao, Bin Xing

    Abstract Support vector machine (SVM) is one of the effective classifiers in the field of network intrusion detection; however, some important information related to classification might be lost in the reprocessing. In this paper, we propose a granular classifier based on entropy clustering method and support vector machine to overcome this limitation. The overall design of classifier is realized with the aid of if-then rules that consists of a premise part and conclusion part. The premise part realized by the entropy clustering method is used here to address the problem of a possible curse of dimensionality, while the conclusion part realized by support vector machines is utilized to build local models. In contrast to the conventional SVM, the proposed entropy clustering-based granular classifiers (ECGC) can be regarded as an entropy-based support function machine. Moreover, an opposition-based genetic algorithm is proposed to optimize the design parameters of the granular classifiers. Experimental results show the effectiveness of the ECGC when compared with some classical models reported in the literatures.

    更新日期:2020-01-04
  • Separation characteristics between time domain and frequency domain of wireless power communication signal in wind farm
    EURASIP J. Wirel. Commun. Netw. (IF 1.592) Pub Date : 2020-01-03
    Jie Wan, Kun Yao, E. Peng, Yong Cao, Yuguang NIU, Jilai Yu

    Understanding the intrinsic characteristics of wind power is important for the safe and efficient parallel function of wind turbines in large-scale wind farms. Current research on the spectrum characteristics of wind power focuses on estimation of power spectral density, particularly the structural characteristics of Kolmogorov’s scaling law. In this study, the wavelet Mallat algorithm, which is different from the conventional Fourier transform, with compactly supported characteristics is used to extract the envelope of the signal and analyze the instantaneous spectral characteristics of wind power signals. Then, the theory for the change in the center frequency of the wind power is obtained. The results showed that within a certain range, the center frequency decreases as the wind power increases by using enough wind farm data. In addition, the center frequency remains unchanged when the wind power is sufficiently large. Together with the time domain characteristics of wind power fluctuation, we put forward the time-frequency separation characteristics of wind power and the corresponding physical parameter expressions, which corresponds to wind speed’s amplitude and frequency modulation characteristics. Lastly, the physical connotation of the time-frequency separation characteristics of wind power from the perspective of atmospheric turbulent energy transport mechanism and wind turbine energy transfer mechanism is established.

    更新日期:2020-01-04
  • A traffic data collection and analysis method based on wireless sensor network
    EURASIP J. Wirel. Commun. Netw. (IF 1.592) Pub Date : 2020-01-02
    Huan Wang, Min Ouyang, Qingyuan Meng, Qian Kong

    Abstract With the rapid development of urbanization, collecting and analyzing traffic flow data are of great significance to build intelligent cities. The paper proposes a novel traffic data collection method based on wireless sensor network (WSN), which cannot only collect traffic flow data, but also record the speed and position of vehicles. On this basis, the paper proposes a data analysis method based on incremental noise addition for traffic flow data, which provides a criterion for chaotic identification. The method adds noise of different intensities to the signal incrementally by an improved surrogate data method and uses the delayed mutual information to measure the complexity of signals. Based on these steps, the trend of complexity change of mixed signal can be used to identify signal characteristics. The numerical experiments show that, based on incremental noise addition, the complexity trends of periodic data, random data, and chaotic data are different. The application of the method opens a new way for traffic flow data collection and analysis.

    更新日期:2020-01-02
  • A new load balancing strategy by task allocation in edge computing based on intermediary nodes
    EURASIP J. Wirel. Commun. Netw. (IF 1.592) Pub Date : 2020-01-02
    Guangshun Li, Yonghui Yao, Junhua Wu, Xiaoxiao Liu, Xiaofei Sheng, Qingyan Lin

    The latency of cloud computing is high for the reason that it is far from terminal users. Edge computing can transfer computing from the center to the network edge. However, the problem of load balancing among different edge nodes still needs to be solved. In this paper, we propose a load balancing strategy by task allocation in edge computing based on intermediary nodes. The intermediary node is used to monitor the global information to obtain the real-time attributes of the edge nodes and complete the classification evaluation. First, edge nodes can be classified to three categories (light-load, normal-load, and heavy-load), according to their inherent attributes and real-time attributes. Then, we propose a task assignment model and allocate new tasks to the relatively lightest load node. Experiments show that our method can balance load among edge nodes and reduce the completion time of tasks.

    更新日期:2020-01-02
  • Experimental analysis and evaluation of wide residual networks based agricultural disease identification in smart agriculture system
    EURASIP J. Wirel. Commun. Netw. (IF 1.592) Pub Date : 2019-12-30
    Haoxu Yang, Lutao Gao, Niansheng Tang, Po Yang

    Specialised pest and disease control in the agricultural crops industry have been a high-priority issue. Due to great cost-effectiveness and efficient automation, computer vision (CV)–based automatic pest or disease identification techniques are widely utilised in the smart agricultural systems. As rapid development of artificial intelligence, in the field of computer vision–based agricultural pest identification, an increasing number of scholars have begun to move their attentions from traditional machine learning models to deep learning techniques. However, so far, deep learning techniques still have been suffering from many problems such as limited data samples, cost-effectiveness of network structure, and high image quality requirements. These issues greatly limit the potential utilisation of deep-learning techniques into smart agricultural systems. This paper aims at investigating utilization of one new deep-learning model WRN (wide residual networks) into CV-based automatic disease identification problem. We first built up a large-scale agricultural disease images dataset containing over 36,000 pieces of diseases, which includes typical types of disease in tomato, potato, grape, corn and apple. Then, we analysed and evaluated wide residual networks algorithm using the Tesla K80 graphics processor (GPU) in the TensorFlow deep-learning framework. A set of comprehensive experimental protocols have been designed in comparing with GoogLeNet Inception V4 regarding several benchmarks. The experimental results indicate that (1) under WRN architecture, Softmax loss function gives a faster convergence and improved accuracy than GoogLeNet inception V4 network. (2) While WRN shows a good effect for identification of agricultural diseases, its effectiveness has a strong need on the number of training samples of dataset like at least 36 k images in our experiment. (3) The overall performance is better than 800 sheets. The disease identification results show that the WRN model can be applied to the identification of agricultural diseases.

    更新日期:2019-12-31
  • Land subsidence monitoring based on InSAR and inversion of aquifer parameters
    EURASIP J. Wirel. Commun. Netw. (IF 1.592) Pub Date : 2019-12-30
    Zhang Ziwen, Yijun Liu, Feng Li, Qi Li, Wujian Ye

    Abstract In order to accurately separate the elastic and inelastic deformation information caused by aquifer compression in the land subsidence signal, and to invert the hydrogeological parameters of high spatial and temporal resolution to better apply the groundwater-ground subsidence model, a CWT (Continuous Wavelet Transform) separation method for aquifer elastic and inelastic deformation signals based on CWT is adopted, and the deformation signal is extracted by InSAR technology. The large-scale synthetic aperture radar dataset obtained by Envisat satellite from 2007 to 2009 is collected to obtain the surface deformation characteristic of the area by SBAS-InSAR technology, and then the independence provided by the observation well is used. Using the independent water level data provided by the observation wells, combined with the vertical InSAR deformation component and the head data, the CWT method is used to separate the periodic deformation signal components and long-term trends. Finally, the isolated signal component is used to invert the elastic and inelastic storage coefficient based on the ground subsidence model. The settlement signal separation method used in this paper makes up for the shortcomings of the two kinds of information in the previous settlement signal that are difficult to separate, which allows for more accurate inversion of aquifer parameters and helps to understand the aquifer parameters and continuously manage groundwater resources.

    更新日期:2019-12-31
  • Joint measure matrix and channel estimation for millimeter-wave massive MIMO with hybrid precoding
    EURASIP J. Wirel. Commun. Netw. (IF 1.592) Pub Date : 2019-12-30
    Shufeng Li, Baoxin Su, Libiao Jin, Mingyu Cai, Hongda Wu

    Millimeter-wave (mmWave) massive multiple-input multiple-output (MIMO) with hybrid precoding is a promising technology for future 5G wireless communications. Channel estimation for the millimeter-wave (mmWave) MIMO systems with hybrid precoding can be performed by estimating the path directions of the channel and corresponding path gains. This paper considers joint measure matrix and channel estimation for a massive MIMO system. By exploiting the sparsity of a massive MIMO system, a channel estimation scheme based on a Toeplitz-structured measure matrix and complete complementary sequence (CC-S) is proposed. Moreover, analytic studies show that the measurement matrix based on CC-S yields either optimal performance or feasibility in practice than an independent identically distributed Gaussian matrix. The performance of the scheme is shown with numerical examples.

    更新日期:2019-12-31
  • Ingredients to enhance the performance of two-stage TCAM-based packet classifiers in internet of things: greedy layering, bit auctioning and range encoding
    EURASIP J. Wirel. Commun. Netw. (IF 1.592) Pub Date : 2019-12-30
    Mahdi Abbasi, Shakoor Vakilian, Ali Fanian, Mohammad R. Khosravi

    Using packet classification algorithms in network equipment increases packet processing speed in Internet of Things (IoT). In the hardware implementation of these algorithms, ternary content-addressable memories (TCAMs) are often preferred to other implementations. As a common approach, TCAMs are used for the parallel search to match packet header information with the rules of the classifier. In two-stage architectures of hardware-based packet classifiers, first the decision tree is created, and then the rules are distributed among its leaves. In the second step, depending on the corresponding leaves, the second part of the rules, which includes the range of source and destination ports is stored in different blocks of TCAM. Due to inappropriate storage of port range fields, the existing architectures face the problem of wasting memory and growing power consumption. This paper proposes an efficient algorithm to encode the port range. This algorithm consists of three general steps including layering, bit allocation, and encoding. A greedy algorithm in the first step places the ranges with higher weights in higher layers. Next, an auction-based algorithm allocates several bits to each layer depending on the number of the ranges in that layer. Finally, in each layer, depending on the weight order of the ranges, the bits are given values for the intended range. The evaluation results show that unlike previous methods of storing range fields, the proposed method not only increases the speed of the classification but also uses the capacity of TCAM in the second stage more efficiently.

    更新日期:2019-12-30
  • Channel estimation via gradient pursuit for mmWave massive MIMO systems with one-bit ADCs
    EURASIP J. Wirel. Commun. Netw. (IF 1.592) Pub Date : 2019-12-30
    In-soo Kim, Junil Choi

    In millimeter wave (mmWave) massive multiple-input multiple-output (MIMO) systems, 1 bit analog-to-digital converters (ADCs) are employed to reduce the impractically high power consumption, which is incurred by the wide bandwidth and large arrays. In practice, the mmWave band consists of a small number of paths, thereby rendering sparse virtual channels. Then, the resulting maximum a posteriori (MAP) channel estimation problem is a sparsity-constrained optimization problem, which is NP-hard to solve. In this paper, iterative approximate MAP channel estimators for mmWave massive MIMO systems with 1 bit ADCs are proposed, which are based on the gradient support pursuit (GraSP) and gradient hard thresholding pursuit (GraHTP) algorithms. The GraSP and GraHTP algorithms iteratively pursue the gradient of the objective function to approximately optimize convex objective functions with sparsity constraints, which are the generalizations of the compressive sampling matching pursuit (CoSaMP) and hard thresholding pursuit (HTP) algorithms, respectively, in compressive sensing (CS). However, the performance of the GraSP and GraHTP algorithms is not guaranteed when the objective function is ill-conditioned, which may be incurred by the highly coherent sensing matrix. In this paper, the band maximum selecting (BMS) hard thresholding technique is proposed to modify the GraSP and GraHTP algorithms, namely, the BMSGraSP and BMSGraHTP algorithms, respectively. The BMSGraSP and BMSGraHTP algorithms pursue the gradient of the objective function based on the band maximum criterion instead of the naive hard thresholding. In addition, a fast Fourier transform-based (FFT-based) fast implementation is developed to reduce the complexity. The BMSGraSP and BMSGraHTP algorithms are shown to be both accurate and efficient, whose performance is verified through extensive simulations.

    更新日期:2019-12-30
  • Analysis of node deployment in wireless sensor networks in warehouse environment monitoring systems
    EURASIP J. Wirel. Commun. Netw. (IF 1.592) Pub Date : 2019-12-30
    Jia Mao, Xiaoxi Jiang, Xiuzhi Zhang

    This paper mainly studies the deployment of wireless sensor network nodes in the warehouse environment monitoring system, discusses the deployment algorithm of wireless sensor network nodes in the warehouse environment, and finds out the node deployment scheme with better network performance through comparison. Wireless sensor network node deployment is the basis of wireless sensor network application in storage environment monitoring system. It affects the performance of the whole network and is the primary problem to be solved in network application. This paper discusses the advantages of wireless sensor network in the monitoring of storage environment, especially the deployment and simulation analysis of sensor nodes in the warehouse environment. Aiming at the influence of sensor perception model on the effectiveness of the node deployment plan, this paper proposes a node deployment collaborative perception model based on 0-1 perception model and exponential model. The sensor node deployment problem is transformed into a three-dimensional node deployment problem. Finally, the algorithm is applied to tobacco storage environment. In order to verify the effectiveness of the proposed algorithm, the scheme obtained by the proposed algorithm is compared with that obtained by the corresponding deployment algorithm in this paper. The comparison results show that the overall performance of the algorithm is better than that of the usual scheme.

    更新日期:2019-12-30
  • Multi-beam coverage and beamforming technology for high altitude platform station communication system
    EURASIP J. Wirel. Commun. Netw. (IF 1.592) Pub Date : 2019-12-30
    Mingxiang Guan, Zhou Wu, Yingjie Cui, Xuemei Cao, Le Wang, Jianfeng Ye, Bao Peng

    Multi-beam antenna technology can effectively mitigate the impact of deep fading caused by multipath propagation on communication quality through spatial diversity and increase the reliability of wireless mobile communication systems. At the same time, the multi-beam antenna with beamforming algorithm as the key technology can realize spatial division multiple access (SDMA) by automatically adapting the weight vector of the antenna array, enhance the expected value, and suppress the interference. A novel beamforming technology increases the inner circle beam width and reduces the outer ring beam width to minimize the difference between the internal and external cell link SNR. This study considers reducing the number of cells by reasonably allocating beams, which satisfies both the requirements of coverage link quality and the difficulty of forming antenna beams. This research subject applies the scheme and strategy of improving multi-beam antenna technology in the same system. Under the requirement of cell coverage and partitioning, the related technologies and strategies combining multi-beamforming technology and space-time block code technology can obtain high coding gain and diversity gain without sacrificing bandwidth and effectivelyx improve the wireless systematic capacity.

    更新日期:2019-12-30
  • A fusion optimization algorithm of network element layout for indoor positioning
    EURASIP J. Wirel. Commun. Netw. (IF 1.592) Pub Date : 2019-12-27
    Xiao-min Yu, Hui-qiang Wang, Hong-wu Lv, Xiu-bing Liu, Jin-qiu Wu

    The indoor scene has the characteristics of complexity and Non-Line of Sight (NLOS). Therefore, in the application of cellular network positioning, the layout of the base station has a significant influence on the positioning accuracy. In three-dimensional indoor positioning, the layout of the base station only focuses on the network capacity and the quality of positioning signal. At present, the influence of the coverage and positioning accuracy has not been considered. Therefore, a network element layout optimization algorithm based on improved Adaptive Simulated Annealing and Genetic Algorithm (ASA-GA) is proposed in this paper. Firstly, a three-dimensional positioning signal coverage model and a base station layout model are established. Then, the ASA-GA algorithm is proposed for optimizing the base station layout scheme. Experimental results show that the proposed ASA-GA algorithm has a faster convergence speed, which is 16.7% higher than the AG-AC (Adaptive Genetic Combining Ant Colony) algorithm. It takes about 25 generations to achieve full coverage. At the same time, the proposed algorithm has better coverage capability. After optimization of the layout of the network element, the effective coverage rate is increased from 89.77 to 100% and the average location error decreased from 2.874 to 0.983 m, which is about 16% lower than the AG-AC algorithm and 22% lower than the AGA (Adaptive Genetic Algorithm) algorithm.

    更新日期:2019-12-27
  • On Gaussian covert communication in continuous time
    EURASIP J. Wirel. Commun. Netw. (IF 1.592) Pub Date : 2019-12-27
    Ligong Wang

    Abstract The paper studies covert communication over a continuous-time Gaussian channel. The covertness condition requires that the channel output must statistically resemble pure noise. When the additive Gaussian noise is “white” over the bandwidth of interest, a formal coding theorem is proven, extending earlier results on covert Gaussian communication in discrete time. This coding theorem is applied to study scenarios where the input bandwidth can be infinite and where positive or even infinite per-second rates may be achievable.

    更新日期:2019-12-27
  • Exploiting prospect theory and risk-awareness to protect UAV-assisted network operation
    EURASIP J. Wirel. Commun. Netw. (IF 1.592) Pub Date : 2019-12-27
    Panagiotis Vamvakas, Eirini Eleni Tsiropoulou, Symeon Papavassiliou

    In this paper, a novel resource management framework is introduced and exploited to ensure the efficient and smooth operation of a wireless network, assisted by an unmanned aerial vehicle (UAV), operating under the non-orthogonal multiple access (NOMA) scheme and consisting of both normal and malicious risk-aware users. User devices are assumed capable of splitting their transmission power in two different communication alternatives, established via either the UAV or the macro base station (MBS). The bandwidth offered by the UAV is accessible by everyone, delivers potentially higher rate of return taking into account the enhanced communication channel gains owing to its proximity to the serving users, but is prone to failure due to its potential over-exploitation. Accordingly, the UAV’s bandwidth is considered as common pool of resources (CPR). In contrast, the MBS’s bandwidth is considered as a safe resource offering to the users a more limited but guaranteed level of service, due to the fact that though it has less available bandwidth it operates under a more controlled access scheme. The theory of the tragedy of the commons is used to capture the probability of failure of the CPR, while the prospect theory is adopted to study the normal and malicious users’ risk-aware behavior in the UAV-assisted network. A non-cooperative power control game among the users is formulated and solved, in order to determine the users’ power investment to the dual communication environment. The existence and uniqueness of a Pure Nash Equilibrium point is shown and a distributed algorithm is introduced to converge to the PNE point. This overall resource allocation framework is intelligently exploited as the vehicle to detect malicious user behavior and therefore protect the network from the undesired effects of such behaviors. The performance and inherent attributes of the proposed user-centric risk-aware operation framework, in terms of its capability to effectively utilize the available system and user resources (i.e., bandwidth and power), while succeeding in identifying potential abnormal or malicious user behaviors is assessed via modeling and simulation, under different operation scenarios.

    更新日期:2019-12-27
  • Robust proactive eavesdropping in UAV-enabled wireless communication networking
    EURASIP J. Wirel. Commun. Netw. (IF 1.592) Pub Date : 2019-12-27
    Wei Wu, Yujing Wang, Jianlin Mo, Jian Liu

    In this paper, we considered a robust beamforming design problem for a proactive eavesdropping via jamming, in which a full-duplex legitimate monitor tries to eavesdrop on a suspicious communication link between the secondary pairs in an unmanned aerial vehicle (UAV)-enabled cognitive radio network. Due to the channel estimation errors, we assume that the channel state information is not perfectly known. To ensure the successful eavesdropping, jamming signals are designed to disrupt the suspicious receivers and the primary receiver at the same time, which should have the good tradeoff between those two effects. We aimed to maximize the achievable eavesdropping rate under the transmitting power constraint at the legitimate monitor and the interference temperature constraint at the primary receiver, which was formulated as a non-convex problem with infinite constraints. We firstly transform the original problem into a simplified one with finite constraints. Then, an analytical solution in significant low-complexity is proposed by decomposing the simplified problem. Numerical results are finally presented to evaluate the performance of our proposed schemes in UAV-enabled wireless communication networking.

    更新日期:2019-12-27
  • Control plane delay minimization-based capacitated controller placement algorithm for SDN
    EURASIP J. Wirel. Commun. Netw. (IF 1.592) Pub Date : 2019-12-26
    Rong Chai, Qiongfang Yuan, Lei Zhu, Qianbin Chen

    Software-defined networking (SDN) is proposed as a new network paradigm which decouples control plane from data plane and provides flexible network management. In this paper, we consider the capacitated controller placement problem in SDN, which jointly determines the number, location, and the capacity matching strategy of SDN controllers. redTo stress the importance of control plane delay which is composed of both the transmission and processing delay between controllers and switches, and the inter-controller delay; we formulate control plane delay minimization problem subject to controller-switch association constraints, controller capacity constraints, etc. Since the formulated optimization problem is a complicated nonlinear integer programming problem which cannot be solved easily, we transform it into controller-switch association subproblem and controller capacity matching subproblem. To solve the controller-switch association subproblem, we propose a heuristic algorithm based on Dijkstra algorithm and K-means algorithm. Given the controller-switch association strategy, we then apply the Kuhn-Munkres (K-M) algorithm to solve the controller capacity matching subproblem and obtain the capacitated controller placement strategy. Simulation results are shown to demonstrate the effectiveness of the proposed algorithm.

    更新日期:2019-12-27
  • Modeling the UE-perceived cellular network performance following a controller-based approach
    EURASIP J. Wirel. Commun. Netw. (IF 1.592) Pub Date : 2019-12-21
    Jessica Mendoza, David Palacios, Isabel de-la-Bandera, Eduardo Baena, Emil J Khatib, Raquel Barco

    Abstract During the last few years, mobile communication networks have experienced a huge evolution. This evolution culminates with the arrival of the fifth generation (5G) of mobile communication networks. As a result, the complexity of network management tasks has been increasing and the need to use automatic management algorithms has been demonstrated. However, many mobile network operators (MNOs) are reluctant to evaluate these algorithms in their networks. To address this issue, in this paper, a modeling approach is proposed. In this sense, the behavior of a commercial network, as it is perceived by user equipments (UEs), has been replicated in a research testbed using a three-step modeling process. The first step consists on performing a measurement campaign in several external networks. The second step is composed of the measurement campaign result analysis and the classification of the results in different types of scenarios. Finally, the third step is related to the application of a modeling algorithm in a research testbed. In order to perform the last step, the use of a method based on a controller is proposed. The modeling process presented in this paper allows to replicate the network behavior from users located in different areas and with different conditions point of view. Moreover, the use of a testbed environment can help to avoid downtime in commercial networks caused by possible algorithm bugs.

    更新日期:2019-12-21
  • Personalized project recommendations: using reinforcement learning
    EURASIP J. Wirel. Commun. Netw. (IF 1.592) Pub Date : 2019-12-21
    Faxin Qi, Xiangrong Tong, Lei Yu, Yingjie Wang

    Abstract With the development of the Internet and the progress of human-centered computing (HCC), the mode of man-machine collaborative work has become more and more popular. Valuable information in the Internet, such as user behavior and social labels, is often provided by users. A recommendation based on trust is an important human-computer interaction recommendation application in a social network. However, previous studies generally assume that the trust value between users is static, unable to respond to the dynamic changes of user trust and preferences in a timely manner. In fact, after receiving the recommendation, there is a difference between actual evaluation and expected evaluation which is correlated with trust value. Based on the dynamics of trust and the changing process of trust between users, this paper proposes a trust boost method through reinforcement learning. Recursive least squares (RLS) algorithm is used to learn the dynamic impact of evaluation difference on user’s trust. In addition, a reinforcement learning method Deep Q-Learning (DQN) is studied to simulate the process of learning user’s preferences and boosting trust value. Experiments indicate that our method applied to recommendation systems could respond to the changes quickly on user’s preferences. Compared with other methods, our method has better accuracy on recommendation.

    更新日期:2019-12-21
  • Energy harvesting and information transmission scheme with UAV relay cooperation
    EURASIP J. Wirel. Commun. Netw. (IF 1.592) Pub Date : 2019-12-19
    Baofeng Ji, Zhenzhen Chen, Yuqi Li, Sudan Chen, Guoqiang Zheng, Hong Wen

    This paper proposed a system architecture model of two-hop unmanned aerial vehicle (UAV) relay wireless communication and designed an energy harvesting and information transmission algorithm based on the energy harvested by UAV relay node. The energy of nodes except source node can be obtained by energy harvesting and all the UAV relay nodes transmitted signals via power splitting. Under the advance of non-static channel, the information user nodes were configured with multiple antennas and adopted max ratio combination (MRC). Based on the optimization criterion of energy efficiency maximization, the analytical solution of the optimal power allocation scheme for energy harvested and information transmission of multi-user two-UAV relay system was derived in detail. Since the optimization problem was a non-convex problem, this paper adopted the high signal-to-noise ratio approximation method and the power splitting method to realize the closed-form solution expression. The optimal solution of the objective function subjected with constraints can be obtained by Lagrangian algorithm and Lambert W function. Finally, the proposed algorithms and theoretical analysis are verified by simulations.

    更新日期:2019-12-19
  • Multi-security-level cloud storage system based on improved proxy re-encryption
    EURASIP J. Wirel. Commun. Netw. (IF 1.592) Pub Date : 2019-12-18
    Jinan Shen, Xuejian Deng, Zhenwu Xu

    Based on the characteristics and data security requirements of the cloud environment, we present a scheme for a multi-security-level cloud storage system that is combined with AES symmetric encryption and an improved identity-based proxy re-encryption (PRE) algorithm. Our optimization includes support for fine-grained control and performance optimization. Through a combination of attribute-based encryption methods, we add a fine-grained control factor to our algorithm in which each authorization operation is only valid for a single factor. By reducing the number of bilinear mappings, which are the most time-consuming processes, we achieve our aim of optimizing performance. Last but not least, we implement secure data sharing among heterogeneous cloud systems. As shown in experiment, our proposed multi-security-level cloud storage system implements services such as the direct storage of data, transparent AES encryption, PRE protection that supports fine-grained and ciphertext heterogeneous transformation, and other functions such as authentication and data management. In terms of performance, we achieve time-cost reductions of 29.8% for the entire process, 48.3% for delegation and 47.2% for decryption.

    更新日期:2019-12-19
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