Publishing type：Research paper (scientific journal)   Publisher：MDPI AG  

This paper presents a method for analyzing the symbol error rate (SER) of a UAV cellular data network based on an IRS. This method can change the distances between the BS, IRS, UAV, and the elevation of the UAV to observe their impacts on the SER; then, a two-dimensional curve diagram of the parameters and the SER is drawn to determine the deployment position of the UAV. Finally, by flexibly changing the maximum angle of the UAV’s transmitted signal and the height of the UAV, the coverage area of the UAV’s cellular data network can be obtained through three-dimensional imaging, function fitting, and the extreme value of the condition function. As a relay of a cellular data network, a UAV can be flexibly deployed at any effective position at a low altitude to compensate for the limited coverage of the base station and the poor quality of the user’s received signal. In particular, an IRS deployed on the surface of a building can generate an equivalent line-of-sight channel to reflect the signal from the base station to the UAV. Using an IRS to change the signal phase and amplitude with the flexible deployment of UAVs can give priority to solving the problems of cellular data network coverage and signal quality in urban scenarios.

DOI： 10.3390/electronics11203306

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Publishing type：Research paper (scientific journal)   Publisher：Hindawi Limited  

With the popularity of 5G mobile communication services, the number of users has increased dramatically, as well as the nonuniformity of user density distribution; many users are in nonideal channel conditions, so unmanned aerial vehicle (UAV) as a passive relay equipment platform has gradually entered people’s vision. Intelligent reflective surfaces (IRSs) capable of reconfiguring electromagnetic absorption and reflection properties in real-time are offering unprecedented opportunities to enhance wireless communication experience in challenging environments. In this paper, we start from the point of minimizing the energy consumption and nodes of UAV passive relay; the paper proposes to install intelligent reflecting surface (IRS) on UAV as a new passive relay and establish the communication coverage model of UAV-IRS. Then, the main relationship between the coverage radius and hover height of UAV-IRS is verified. In view of different distribution densities of target users, a CK++ (cyclic k-means++) is proposed to solve the spatial deployment problem of UAV-IRS, where the optimal solution of the system is obtained through cyclic clustering. And the algorithm is verified to effectively improve the performance of urban mobile communication and user communication service quality through numerical stimulation.

DOI： 10.1155/2022/7916305

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Other Link： http://downloads.hindawi.com/journals/wcmc/2022/7916305.xml

Publishing type：Research paper (scientific journal)   Publisher：MDPI AG  

In view of the fact that indoor positioning systems are usually affected by non-Gaussian noise in complex indoor environments, this paper tests the data in the actual scene and analyzes the distribution characteristics of noise, and proposes a new indoor positioning algorithm based on maximum correntropy unscented information filter (MCUIF). The proposed indoor positioning algorithm includes three steps: First, the estimation of the state matrix and the corresponding covariance matrix are predicted through the unscented transformation (UT). Second, the observed information is reconstructed by using a nonlinear regression method on the basis of the maximum correntropy criterion (MCC). Third, the contribution of information vector is gained by non-Gaussian measurement and the predicted information vector is corrected by the contribution of information vector. Finally, the gain of information filtering is got by the information entropy state matrix and the information entropy measurement matrix to calculate the position coordinates of the unknown nodes. This algorithm enhances the robustness of the MCUIF to non-Gaussian noise in complex indoor environments. The results from the indoor positioning experiments show that MCUIF is better than the traditional methods in state estimation and position location of the unknown nodes.

DOI： 10.3390/ijgi10070441

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Publishing type：Research paper (scientific journal)   Publisher：Hindawi Limited  

The conventional matrix completion (MC) regularizes each singular value equally, and thus the rank cannot be well approximated, which greatly limits the flexibility and accuracy of MC usage. In this paper, a truncated MC algorithm using prior information to determine the threshold while generating the target rank is proposed for the wind turbine clutter suppression of weather radar. During the singular value shrinking process, an appropriate threshold is selected to obtain the optimal approximation of the sampling matrix. Specifically, the mean value of the diagonal element in the recovered weather matrix is calculated to improve the robustness of the recovery result effectively. Simulation results demonstrate that the proposed algorithm reduces the computational complexity as well as further improves the MC accuracy and realizes the effective suppression of the wind turbine clutter.

DOI： 10.1155/2021/8814415

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Other Link： http://downloads.hindawi.com/journals/mpe/2021/8814415.xml

Publishing type：Research paper (scientific journal)   Publisher：Institution of Engineering and Technology (IET)  

DOI： 10.1049/cmu2.12062

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Other Link： https://onlinelibrary.wiley.com/doi/full-xml/10.1049/cmu2.12062

Publishing type：Research paper (scientific journal)   Publisher：Institution of Engineering and Technology (IET)  

DOI： 10.1049/iet-com.2020.0378

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Other Link： https://onlinelibrary.wiley.com/doi/full-xml/10.1049/iet-com.2020.0378

Publishing type：Research paper (scientific journal)   Publisher：Institute of Electrical and Electronics Engineers (IEEE)  

DOI： 10.23919/jcc.2020.10.019

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Publishing type：Research paper (scientific journal)   Publisher：IOP Publishing  

Abstract

The three-dimensional positioning of nodes is a major and basic problem in wireless sensor networks. It has an important application value in areas such as search and rescue, target tracking, disaster reduction and intelligent environment. This paper presents a three-dimensional four-point centroid location algorithm based on RSSI. Based on signal strength between unknown nodes and known nodes, a received signal strength indicator (RSSI) propagation model in shadow mode is established. The Gaussian model is employed to RSSI. The signal strength is rectified to obtain a more accurate ranging model. In a three-dimensional space, a reasonable detection point is selected, and the centroid iteration algorithm is used twice. The weighted centroid algorithm is utilized for the first time and the average centroid algorithm is used for the second time to find the target. The coordinates of the nodes realizes the three-dimensional spatial positioning of the unknown nodes. Through simulation experiments, the positioning algorithm has improved accuracy and stability compared with the least square method and weighted centroid algorithm.

DOI： 10.1088/1742-6596/1550/3/032022

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Other Link： https://iopscience.iop.org/article/10.1088/1742-6596/1550/3/032022

Publishing type：Research paper (scientific journal)   Publisher：Elsevier BV  

DOI： 10.1016/j.phycom.2019.100985

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Publishing type：Research paper (scientific journal)   Publisher：Elsevier BV  

DOI： 10.1016/j.mri.2019.05.042

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Publishing type：Research paper (scientific journal)   Publisher：Institution of Engineering and Technology (IET)  

DOI： 10.1049/iet-com.2018.5228

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Other Link： https://onlinelibrary.wiley.com/doi/full-xml/10.1049/iet-com.2018.5228

Publishing type：Research paper (scientific journal)   Publisher：Institute of Electrical and Electronics Engineers (IEEE)  

DOI： 10.23919/jcc.2019.06.012

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Publishing type：Research paper (scientific journal)   Publisher：Institute of Electrical and Electronics Engineers (IEEE)  

DOI： 10.1109/access.2019.2920149

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Publishing type：Part of collection (book)   Publisher：Springer Singapore  

DOI： 10.1007/978-981-13-2384-3_24

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Publishing type：Research paper (scientific journal)   Publisher：Hindawi Limited  

As a key technology in Long-Term Evolution-Advanced (LTE-A) mobile communication systems, heterogeneous cellular networks (HCNs) add low-power nodes to offload the traffic from macro cell and therefore improve system throughput performance. In this paper, we investigate a joint user association and resource allocation scheme for orthogonal frequency division multiple access- (OFDMA-) based downlink HCNs for maximizing the energy efficiency and optimizing the system resource. The algorithm is formulated as a nonconvex optimization, with dynamic circuit consumption, limited transmit power, and quality-of-service (QoS) constraints. As a nonlinear fractional problem, an iteration-based algorithm is proposed to decompose the problem into two subproblems, that is, user association and power allocation. For each iteration, we alternatively solve the two subproblems and obtain the optimal user association and power allocation strategies. Numerical results illustrate that the proposed iteration-based algorithm outperforms existing algorithms.

DOI： 10.1155/2018/7091512

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Other Link： http://downloads.hindawi.com/journals/misy/2018/7091512.xml

Publishing type：Research paper (scientific journal)   Publisher：Elsevier BV  

DOI： 10.1016/j.phycom.2018.02.002

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Publishing type：Research paper (scientific journal)   Publisher：MDPI AG  

DOI： 10.3390/robotics6040030

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Publishing type：Research paper (scientific journal)   Publisher：Institution of Engineering and Technology (IET)  

DOI： 10.1049/iet-com.2017.0124

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Other Link： https://onlinelibrary.wiley.com/doi/full-xml/10.1049/iet-com.2017.0124

Publishing type：Research paper (scientific journal)   Publisher：Hindawi Limited  

Cognitive radio (CR) is a promising solution to address the more and more congested radio spectrum. Cooperative relaying can provide a better transmission performance for the secondary user (SU), while the performance of the primary user (PU, also named licensed user) should be preferentially protected especially when there is misdetection probability. In this paper, in order to keep the PU away from outage caused by the interference from the SU under a certain signal-to-noise ratio (SNR), the maximum SNR for the SU can be derived by using the rate decaying factor (RDF). Then, based on the maximum channel gain and the maximum SNR, the outage probability is analyzed using decode-and-forward (DF) relaying and amplify-and-forward (AF) relaying schemes. Numerical results show that the outage probability decreases when the power allocation factor increases for DF strategy, while the outage probability has error floor when the power allocation factor increases for AF strategy. And the relaying scheme based on the maximum channel gain outperforms that based on the maximum SNR when the power allocation factor and detection probability are small, while the relaying scheme based on the maximum SNR outperforms that based on the maximum channel gain when the power allocation factor is large. What is more, AF relaying has better outage performance in the practical implementation.

DOI： 10.1155/2016/1051632

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Other Link： http://downloads.hindawi.com/journals/misy/2016/1051632.xml

Publishing type：Research paper (scientific journal)   Publisher：Wiley  

DOI： 10.1002/dac.3099

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Publishing type：Research paper (international conference proceedings)   Publisher：IEEE  

DOI： 10.1109/icsai.2014.7009380

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Publishing type：Research paper (scientific journal)   Publisher：Institution of Engineering and Technology (IET)  

DOI： 10.1049/iet-com.2014.0095

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Other Link： https://onlinelibrary.wiley.com/doi/full-xml/10.1049/iet-com.2014.0095

Publishing type：Research paper (scientific journal)   Publisher：Institution of Engineering and Technology (IET)  

DOI： 10.1049/iet-smt.2013.0218

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Other Link： https://onlinelibrary.wiley.com/doi/full-xml/10.1049/iet-smt.2013.0218

Publishing type：Research paper (scientific journal)   Publisher：Bentham Science Publishers Ltd.  

The efficiency of high speed packet access (HSPA) systems is mainly based on Packet Scheduling Schemewhich will be the key to influencing on the system performance and ensuring the service quality for the users. In thispaper, we introduce a three step packet scheduling scheme to provide quality of services (QoS) guaranteed for high speeduplink packet access. Then, we proposed an improved packet scheduling algorithm based on QoS parameter for mixedservice applications in order to meet the actual QoS needs of the different systems. This algorithm calculated thescheduling priority based on the comprehensive factors, including the queuing status of each user, QoS requirements andthe sum of speeds on each channel. The simulation results show that the performance efficiency of HSPA systemsemployed proposed algorithm is superior compared to the conventional PF and M-LWDF algorithm in average packetdrop and average cell throughput.

DOI： 10.2174/1874155x01408010092

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Other Link： https://openmechanicalengineeringjournal.com/contents/volumes/V8/TOMEJ-8-92/TOMEJ-8-92.xml

Publishing type：Research paper (scientific journal)   Publisher：SAGE Publications  

Dynamic spectrum management is a key technology in cognitive wireless sensor network (C-WSN), in which spectrum sensing plays an important role. In this paper, we propose an improved approach as sparse learning via iterative minimization based on compressive sampling (CS-SLIM) for wideband spectrum detection. CS-SLIM can provide wideband spectrum detection with almost the same accuracy but a lower computational burden than that of SLIM. The measurement matrix and the computational complexity for CS-SLIM are discussed. Mean squared errors (MSEs) at various measurement samples are provided to demonstrate the performance of the proposed approach in sparse scenes. It is also proved that the algorithm is suitable for sparse signal reconstruction and wideband spectrum sensing in C-WSN.

DOI： 10.1155/2013/261953

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Other Link： http://journals.sagepub.com/doi/full-xml/10.1155/2013/261953