Performance Enhancement and Evaluation of IEEE 802.11ah Multi-Access Point Network Using Restricted Access Window Mechanism

2014 ◽  
Author(s):  
Orod Raeesi ◽  
Juho Pirskanen ◽  
Ali Hazmi ◽  
Jukka Talvitie ◽  
Mikko Valkama
Keyword(s):  
Performance Enhancement ◽  
Access Point ◽  
Restricted Access ◽  
Ieee 802.11Ah ◽  
Multi Access

Lightbeam Configuration Method and Interference Elimination Resource Scheduling for Indoor Multibeam VLC Networks

2019 ◽  
Vol 0 (0) ◽  
Author(s):  
Cong-Nam Tran ◽  
Nam-Hoang Nguyen ◽  
Trong-Minh Hoang
Keyword(s):  
Transmission Rate ◽  
Resource Scheduling ◽  
Packet Delay ◽  
Access Point ◽  
Visible Light Communications ◽  
Resource Allocation Algorithm ◽  
Downlink Transmission ◽  
High Data ◽  
Interference Elimination ◽  
Multi Access

AbstractVisible light communications (VLC) is considered as an alternative communications technology for providing indoor wireless services. VLC systems are expected to offer high data transmission rate and seamless coverage. In order to achieve these requirements, VLC systems utilizing multi-lightbeam access points (multibeam VLC-AP) for downlink transmission have been proposed recently. In this paper, we present a lightbeam configuration method and an interference elimination resource scheduling mechanism (IERS) for indoor multibeam multi-access point VLC systems. The proposed lightbeam configuration method ensures seamless connectivity between user equipment and VLC-AP. The proposed IERS mechanism consists of a beam assignment algorithm and a resource allocation algorithm for eliminating co-channel interference as well as improving system performance. Performance results obtained by computer simulation indicate that there are significant improvements in terms of downlink signal to interference plus noise ratio, user throughput and packet delay when the proposed IERS mechanism is deployed.

scholarly journals Aerial Intelligent Reflecting Surface Enabled Terahertz Covert Communications in Beyond-5G Internet of Things

2021 ◽  
Author(s):  
Milad Tatar Mamaghani ◽  
Yi Hong
Keyword(s):  
Wireless Communications ◽  
Internet Of Things ◽  
Optimization Problem ◽  
Data Dissemination ◽  
Performance Enhancement ◽  
Average Energy ◽  
Access Point ◽  
Artificial Noise ◽  
User Scheduling ◽  
Reflecting Surface

<div>Unmanned aerial vehicles (UAVs) are envisioned to be extensively employed for assisting wireless communications in Internet of Things (IoT). </div><div>On the other hand, terahertz (THz) enabled intelligent reflecting surface (IRS) is expected to be one of the core enabling technologies for forthcoming beyond-5G wireless communications that promise a broad range of data-demand applications. In this paper, we propose a UAV-mounted IRS (UIRS) communication system over THz bands for confidential data dissemination from an access point (AP) towards multiple ground user equipments (UEs) in IoT networks. Specifically, the AP intends to send data to the scheduled UE, while unscheduled UEs may behave as potential adversaries. To protect information messages and the privacy of the scheduled UE, we aim to devise an energy-efficient multi-UAV covert communication scheme, where the UIRS is for reliable data transmissions, and an extra UAV is utilized as a cooperative jammer generating artificial noise (AN) to degrade unscheduled UEs detection, improving communication covertness.</div><div>This poses a novel max-min optimization problem in terms of minimum average energy efficiency (mAEE), targetting to improve covert throughput and reduce UAVs' propulsion energy consumption subject to some practical constraints such as covertness which is determined analytically. Since the optimization problem is non-convex, we tackle it via the block successive convex approximation (BSCA) approach to iteratively solve a sequence of approximated convex sub-problems, designing the binary user scheduling, AP's power allocation, maximum AN jamming power, IRS beamforming, and both UAVs' trajectory and velocity planning. Finally, we present a low-complex overall algorithm for system performance enhancement with complexity and convergence analysis. Numerical results are provided to verify our analysis and demonstrate significant outperformance of our design over other existing benchmark schemes.</div>

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