Zhibin Gao

Layered security approach in LTE and simulation

The Third Generation Partnership Project (3GPP) has been specifying the standards of Long Term Evolution (LTE) for 3G radio access. The security concerns in wireless networks might have prevented its further widespread adoption. Layered security approach in LTE is analyzed, an EAP method EAP-Archie used for authentication and ciphering is introduced in this paper. EAP-Archie which embedded in Open Diameter environment is simulated. The result shows it can authentication successfully.

A cross-layer UMTS/WLAN handover algorithm using optimized MIH

Nowadays, WLAN Hotspots can provide various wireless services in any given time or place. With the development of multi-mode terminals, the researches on WLAN technology as the extension of UMTS are undergoing. The IEEE 802.21 standard is a candidate which can provide solutions for seamless handover among heterogeneous networks. In this paper, we propose an enhanced UMTS/WLAN handover mechanism with modification on MIH (Media Independent Handover) and the handover decision algorithm. From the simulation results obtained by Network Simulation-2.29, the better practicality of the proposed approach is verified.

Q-Learning-Based Power Control for LTE Enterprise Femtocell Networks

Small cells are beneficial for both users and operators to improve communication quality. The femtocell is one type of small cell used for indoor coverage. Enterprise femtocell installation inevitably produces intralayer and interlayer interference management issues. Enterprise femtocell optimization and indoor propagation modeling are built in this work based on the communications environment characteristics. Q-learning-based distributed and hybrid power control strategies are then proposed. The throughput, energy efficiency, and user experience satisfaction with conventional scheduling methods are compared. The simulation results show that distributed Q-learning performs better local optimization while hybrid Q-learning enhances global performance.

Resource management for future mobile networks: Architecture and technologies

Compared to fourth-generation (4G) cellular systems, fifth-generation (5G) wireless communication systems face ever-increasing demand for spectral efficiency, energy, high data rates, and throughput as required by new devices and applications. To address these challenges, 5G wireless networks must adopt ultra-dense and heterogeneous networks (HetNet), which render interference and resource management (RM) even more challenging than they are today. In this article, we first review various 5G wireless network architectures proposed in the literature before discussing key 5G wireless technologies for RM. We focus specifically on RM research, which includes spectrum assignment, resource and channel allocation, power control, and interference management based on user-centric cell schemes. Finally, we present a cloud-based user-centric network architecture with emphasis on the networks formation, RM, and interference signal joint-processing via cluster technology to provide higher throughput.

Ray Tracing Based Wireless Channel Modeling over the Sea Surface near Diaoyu Islands

Marine wireless channel modeling is significant to construct a maritime communication system. Three dimensional contour data of Diaoyu Islands is collected and analyzed. Then a three dimensional scene combined with sea surface is rebuilt through Matlab. Ray tracing based on angle searching and the deterministic channel modeling are used to model the wireless channels of the main scenes by air platforms(Unmanned Aerial Vehicle (UAV) or hot-air balloons) which carrying the wireless transceivers. A simulation considering relevant parameters like path loss, time delay and arrival angle are carried out. The results show that the pass loss is interrelated with the rough sea surface which also lead to an uncertain multipath effect.

Optimized adaptive algorithm of digital self-interference cancellation based on improved variable step

Full-duplex wireless communication system transmits and receives signals in a same frequency band and at a same time, which solves the problem of the low using efficiency of limited radio spectrum resource, and doubles the channel capacity. However, it also brings a new problem that the full-duplex node will generate a strong self-interference signal. And to deal with the self-interference signal, using existing negative self-interference cancellation and analog self-interference cancellation technology are not enough, effective digital self-interference cancellation is needed for further cancellation. This paper proposes an optimized adaptive algorithm of digital self-interference cancellation based on improved variable step. By using a iteration threshold, we establish a new nonlinear relationship between the step factor and the error signal, which overcomes the slow change problem when the error signal is getting closed to zero, and accelerates the convergence rate.

Material Intelligent Identification Based on Hyperspectral Imaging and SVM

With the rapid development of economic globalization, the method of material identification in customs is behind the times. The higher identification efficiency is required by the increase of imports. In this paper, a new hyperspectral imaging intelligent material identifying system based on instantly scanning technique is proposed. The system is investigated by an identification experiment with 5 kinds of flour participated. The spectrum imaging device adopted is from MeiyaPico coded CP-2000B. 250 groups of spectral feature (400 to 750 nm) data are collected by the device. Sample sets retreated by removing the envelope using the radial basis function for kernel are transformed into a subspace. The database building and the identification are accompanied by SVM classification algorithm. In the experiments, the accuracy of system proposed is above 95%.

Cluster-Based Timing Synchronization Method for Device-to-Device Communication

Device-to-Device (D2D) communication technology has emerged as an interesting and important area nowadays. In D2D system, Synchronization is a key technology which can ensure effective discovery. There has been extensive research on synchronization method in the context of ad hoc networks during the last few years. However, few of them seems suitable for the D2D communication since they perform badly when there are massive devices. Therefore, a cluster-based timing synchro-nization method for D2D communication with infrastructure is proposed in this paper. The method, which utilize the random access process used in LTE system and build synchronization cluster according to UEs transmission power and battery level, can achieve timing synchronization quickly and easily without complex operation. From the simulation results, we verified that the proposed method can reduce the heavy burden of eNodeB in massive devices scenario compare with classic timing synchro-nization methods. In the meantime, the D2D devices in RRC_idle state can get timing synchronization easily using the proposed method.

A Flexible Carrier Allocation Strategy for Multi-carrier Cell Architecture

Flexible frequency carrier allocation is studied for multiple carrier cell architecture in order to avoid the local network congestion in mobile cellular systems caused by user migration. This strategy satisfies the burst traffic demand of the local hot-spot cell at a specific time and reduces the co-frequency inter cell interference. Dynamic carrier allocation is also considered to satisfy the capacity demand of user migration. Simulations show that this strategy can flexibly allocate carriers, reduce the frequency band cost and capacity redundancy and increase the spectrum utilization rate.

Energy-aware interference management for ultra-dense multi-tier HetNets: Architecture and technologies

Abstract In order to improve spectral efficiency in future ultra-dense heterogeneous networks (HetNets), small cells and macro cells should be ultra-dense when deployed and dynamically overlaid. In this condition, overlaid deployment, state transition, and load migration will cause energy consumption and complex interference. Managing interference in ultra-dense multi-tier HetNets is challenging; interference can burden the network significantly when network conditions change over time. Because of the distribution of small cells and overload conditions in these ultra-dense networks, we must take into account the interference relationship among the base stations and distribution and loading conditions. An interference management scheme based on energy-aware architecture is proposed for ultra-dense multi-tier HetNets in this article. A survey is presented on energy-aware scheduling algorithms. We aim to study energy efficiency issues using graph theory and clustering. HetNets are divided into numerous interference areas, which correspond to coverage areas of each base station. Any conflict among users’ resources depends on if the interference user is located in a base station interference area, hence the use of a reinforcement-learning algorithm to optimize ongoing interference management. Given the complexity of a multi-layer network, conflict graph theory can easily identify network dynamics because it focuses on users’ received interference. Conflict graph theory can also increase resource reusability and efficiency. The proposed scheme can allocate the frequency spectrum equitably, reduce system interference, and improve throughput performance.