Performance Analysis of Heterogeneous Networks in Presence of Deliberate Jammers Using Reverse Frequency Allocation

The demand of high data rate and ubiquitous coverage in heterogeneous cellular (HetNets) is increasing progressively. In order to meet this demand, sophisticated model having applied interference reduction scheme and cell association technique is needed. The small base station (sBS)are deployed inside the broadcasting area of macro base station (mBS), in heterogeneous cellular networks (HetNets). Since mBS has high transmission power therefore a large number of users get connected with mBS. This causes disproportion of load distribution across the HetNets. For load balancing users from high power mBS are migrated to low power sBS to increase network capacity and to decrease the load from mBS. This results in interference in the communication signal because of strong mBS Interference. Hence, we need interference management technique to mitigate interference and user association and to efficiently use sBSs’ resources. Inter-cell interference (ICI) limit the HetNets’ performance. Additionally, there exist deliberate jamming interference which depends on jammers transmission power and its proximity with the target, which notably degrades the network performance. In this paper, we employ reverse frequency allocation scheme (RFA) to reduce inter cell interference, deliberate jamming interference and to accomplish load balancing. The proposed setup is analyzed inquisitively and with the help of simulations. The result shows reduction in interferences as well as balance of load distribution in the network achieved by employing RFA scheme together with cell association.

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Joint Base Station-IRS-User Association in Multi-IRS-Aided Wireless Network

GLOBECOM 2020 - 2020 IEEE Global Communications Conference ◽

10.1109/globecom42002.2020.9347975 ◽

2020 ◽

Author(s):

Weidong Mei ◽

Rui Zhang

Keyword(s):

Wireless Network ◽

Base Station ◽

User Association

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Energy-efficient user association with load-balancing for cooperative IIoT network within B5G era

Journal of Network and Computer Applications ◽

10.1016/j.jnca.2021.103110 ◽

2021 ◽

pp. 103110

Author(s):

Xin Jian ◽

Langyun Wu ◽

Keping Yu ◽

Moayad Aloqaily ◽

Jalel Ben-Othman

Keyword(s):

Load Balancing ◽

Energy Efficient ◽

User Association

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Dynamic Task Migration Combining Energy Efficiency and Load Balancing Optimization in Three-Tier UAV-Enabled Mobile Edge Computing System

Electronics ◽

10.3390/electronics10020190 ◽

2021 ◽

Vol 10 (2) ◽

pp. 190

Author(s):

Wu Ouyang ◽

Zhigang Chen ◽

Jia Wu ◽

Genghua Yu ◽

Heng Zhang

Keyword(s):

Energy Consumption ◽

Load Balancing ◽

Markov Decision Process ◽

Decision Process ◽

Base Station ◽

Edge Computing ◽

Mobile Edge Computing ◽

Task Migration ◽

Migration Strategy ◽

Markov Decision

As transportation becomes more convenient and efficient, users move faster and faster. When a user leaves the service range of the original edge server, the original edge server needs to migrate the tasks offloaded by the user to other edge servers. An effective task migration strategy needs to fully consider the location of users, the load status of edge servers, and energy consumption, which make designing an effective task migration strategy a challenge. In this paper, we innovatively proposed a mobile edge computing (MEC) system architecture consisting of multiple smart mobile devices (SMDs), multiple unmanned aerial vehicle (UAV), and a base station (BS). Moreover, we establish the model of the Markov decision process with unknown rewards (MDPUR) based on the traditional Markov decision process (MDP), which comprehensively considers the three aspects of the migration distance, the residual energy status of the UAVs, and the load status of the UAVs. Based on the MDPUR model, we propose a advantage-based value iteration (ABVI) algorithm to obtain the effective task migration strategy, which can help the UAV group to achieve load balancing and reduce the total energy consumption of the UAV group under the premise of ensuring user service quality. Finally, the results of simulation experiments show that the ABVI algorithm is effective. In particular, the ABVI algorithm has better performance than the traditional value iterative algorithm. And in a dynamic environment, the ABVI algorithm is also very robust.

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Joint Optimization on Trajectory, Cache Placement, and Transmission Power for Minimum Mission Time in UAV-Aided Wireless Networks

ISPRS International Journal of Geo-Information ◽

10.3390/ijgi10070426 ◽

2021 ◽

Vol 10 (7) ◽

pp. 426

Author(s):

Tingting Lan ◽

Danyang Qin ◽

Guanyu Sun

Keyword(s):

Wireless Communication ◽

Power Allocation ◽

Optimization Problems ◽

Base Station ◽

Optimization Techniques ◽

Joint Optimization ◽

Transmission Power ◽

Wireless Backhaul ◽

Mission Time ◽

Cache Placement

In recent years, due to the strong mobility, easy deployment, and low cost of unmanned aerial vehicles (UAV), great interest has arisen in utilizing UAVs to assist in wireless communication, especially for on-demand deployment in emergency situations and temporary events. However, UAVs can only provide users with data transmission services through wireless backhaul links established with a ground base station, and the limited capacity of the wireless backhaul link would limit the transmission speed of UAVs. Therefore, this paper designed a UAV-assisted wireless communication system that used cache technology and realized the transmission of multi-user data by using the mobility of UAVs and wireless cache technology. Considering the limited storage space and energy of UAVs, the joint optimization problem of the UAV’s trajectory, cache placement, and transmission power was established to minimize the mission time of the UAV. Since this problem was a non-convex problem, it was decomposed into three sub-problems: trajectory optimization, cache placement optimization, and power allocation optimization. An iterative algorithm based on the successive convex approximation and alternate optimization techniques was proposed to solve these three optimization problems. Finally, in the power allocation optimization, the proposed algorithm was improved by changing the optimization objective function. Numerical results showed that the algorithm had good performance and could effectively reduce the task completion time of the UAV.

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A Novel Multi-User Codebook Design for 5G in 3D-MIMO Heterogeneous Networks

Electronics ◽

10.3390/electronics7080144 ◽

2018 ◽

Vol 7 (8) ◽

pp. 144 ◽

Cited By ~ 2

Author(s):

Muhammad Arshad ◽

Imran Khan ◽

Jaime Lloret ◽

Ignacio Bosch

Keyword(s):

System Performance ◽

Horizontal Transmission ◽

Feedback Mechanism ◽

Base Station ◽

System Throughput ◽

Codebook Design ◽

Design Scheme ◽

Planar Array ◽

3D Mimo ◽

Inter Cell Interference

The 2D precoding technology can only adjust the beam in a horizontal direction through data processing, which will cause serious problems for multiuser systems, especially at the edge of the base station it will cause serious inter-cell interference. To solve this problem, in the frequency-division duplex (FDD) 3D-MIMO Heterogeneous network system, the influence of feedback overhead on system performance under limited feedback mechanism is studied using random geometry. Based on the deployment of a uniform planar array (UPA) at the base station, a 3D-MIMO multiuser codebook design scheme based on horizontal transmission angle and the vertical down-tilt angle is proposed, and the codebook design scheme is simulated and analyzed. The results show that the feedback overhead and the micro base station density affect the system throughput and even affect the bit error rate (BER) of the 3D precoding scheme. Compared with the precoding scheme based on 2D and 3D discrete Fourier transform (DFT) codebooks, this scheme greatly reduces the system’s BER, improves the system’s throughput, and optimizes system performance.

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Trajectory Planning in UAV Emergency Networks with Potential Underlaying D2D Communication Based on K-means

10.21203/rs.3.rs-144554/v1 ◽

2021 ◽

Author(s):

Shuo Zhang ◽

Shuo Shi ◽

Tianming Feng ◽

Xuemai Gu

Keyword(s):

Trajectory Planning ◽

Communication Systems ◽

High Speed ◽

Large Scale ◽

High Reliability ◽

Base Station ◽

Planning Problem ◽

Communication Signal ◽

User Coverage ◽

Trajectory Length

Abstract Unmanned aerial vehicles (UAVs) have been widely used in communication systems due to excellent maneuverability and mobility. The ultra-high speed, ultra-low latency, and ultra-high reliability of 5th generation wireless systems (5G) have further promoted vigorous development of UAVs. Compared with traditional means of communication, UAV can provide services for ground terminal without time and space constraints, so it is often used as air base station (BS). Especially in emergency communications and rescue, it provides temporary communication signal coverage service for disaster areas. In the face of large-scale and scattered user coverage tasks, UAV's trajectory is an important factor affecting its energy consumption and communication performance. In this paper, we consider a UAV emergency communication network where UAV aims to achieve complete coverage of potential underlying D2D users (DUs). The trajectory planning problem is transformed into the deployment and connection problem of stop points (SPs). Aiming at trajectory length and sum throughput, two trajectory planning algorithms based on K-means are proposed. Due to the non-convexity of sum throughput optimization, we present a sub-optimal solution by using the successive convex approximation (SCA) method. In order to balance the relationship between trajectory length and sum throughput, we propose a joint evaluation index which is used as an objective function to further optimize trajectory. Simulation results show the validity of the proposed algorithms which have advantages over the well-known benchmark scheme in terms of trajectory length and sum throughput.

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