scholarly journals Beam Selection Assisted UAV-BS Deployment and Trajectory for Beamspace mmWave Systems

2021 ◽  
Vol 2021 ◽  
pp. 1-21
Author(s):  
Xingxuan Zuo ◽  
Jiankang Zhang ◽  
Sheng Chen ◽  
Xiaomin Mu
Keyword(s):  
Communication Networks ◽  
Base Stations ◽  
Wireless Communication Networks ◽  
Zero Forcing ◽  
Selection Scheme ◽  
Beam Selection ◽  
Sum Rate ◽  
Selection For ◽  
Orthogonal Beams ◽  
The Given

Exploiting unmanned aerial vehicles (UAVs) as base stations (UAV-BS) can enhance capacity, coverage, and energy efficiency of wireless communication networks. To fully realize this potential, millimeter wave (mmWave) technology can be exploited with UAV-BS to form mmWave UAV-BS. The major difficulty of mmWave UAV-BS, however, lies in the limited energy of UAV-BS and the multiuser interference (MUI). Beam division multiple access with orthogonal beams can be employed to alleviate the MUI. Since each user has dominant beams around the line of sight direction, beam selection can reduce the power consumption of radio frequency chain. In this paper, we formulate the problem of maximizing the sum rate of all users by optimizing the beam selection for beamspace and UAV-BS deployment in the mmWave UAV-BS system. This nonconvex problem is solved in two steps. First, we propose a signal-to-interference plus noise ratio-based greedy beam selection scheme to ensure that all the ground users in the given area can be served by the UAV-BS, where a zero forcing precoding scheme is used to eliminate the MUI. Then, we utilize the continuous genetic algorithm to find the optimal UAV-BS deployment and beam pattern to maximize the sum rate of all users. Moreover, considering the mobility of the UAV-BS, the UAV-BS trajectory and beam selection for beamspace are optimized in the mmWave UAV-BS system. The simulation results demonstrate the effectiveness of the proposed design for the mmWave UAV-BS system.

scholarly journals Technical Note: Novel method for water vapour monitoring using wireless communication networks measurements

2009 ◽  
Vol 9 (7) ◽  
pp. 2413-2418 ◽  
Author(s):  
N. David ◽  
P. Alpert ◽  
H. Messer
Keyword(s):  
Wireless Communication ◽  
Water Vapour ◽  
Communication Networks ◽  
Weather Conditions ◽  
Technical Note ◽  
Base Stations ◽  
Propagation Path ◽  
High Temporal Resolution ◽  
Wireless Communication Networks ◽  
Near Surface

Abstract. We propose a new technique that overcomes the obstacles of the existing methods for monitoring near-surface water vapour, by estimating humidity from data collected through existing wireless communication networks. Weather conditions and atmospheric phenomena affect the electromagnetic channel, causing attenuations to the radio signals. Thus, wireless communication networks are in effect built-in environmental monitoring facilities. The wireless microwave links, used in these networks, are widely deployed by cellular providers for backhaul communication between base stations, a few tens of meters above ground level. As a result, if all available measurements are used, the proposed method can provide moisture observations with high spatial resolution and potentially high temporal resolution. Further, the implementation cost is minimal, since the data used are already collected and saved by the cellular operators. In addition – many of these links are installed in areas where access is difficult such as orographic terrain and complex topography. As such, our method enables measurements in places that have been hard to measure in the past, or have never been measured before. The technique is restricted to weather conditions which exclude rain, fog or clouds along the propagation path. Strong winds that may cause movement of the link transmitter or receiver (or both) may also interfere with the ability to conduct accurate measurements. We present results from real-data measurements taken from two microwave links used in a backhaul cellular network that show convincing correlation to surface station humidity measurements. The measurements were taken daily in two sites, one in northern Israel (28 measurements), the other in central Israel (29 measurements). The correlation between the microwave link measurements and the humidity gauges were 0.9 and 0.82 for the north and central sites, respectively. The Root Mean Square Differences (RMSD) were 1.8 g/m3 and 3.4 g/m3 for the northern and central site measurements, respectively.

scholarly journals Intercell Interference Coordination through Limited Feedback

2010 ◽  
Vol 2010 ◽  
pp. 1-7 ◽  
Author(s):  
Lingjia Liu ◽  
Jianzhong (Charlie) Zhang ◽  
Jae-Chon Yu ◽  
Juho Lee
Keyword(s):  
Wireless Communication ◽  
Communication Networks ◽  
Limited Feedback ◽  
Base Station ◽  
Base Stations ◽  
System Level ◽  
Wireless Communication Networks ◽  
Interference Coordination ◽  
Average Cell ◽  
Intercell Interference

We consider the applications of multicell transmission schemes to the downlink of future wireless communication networks. A multicell multiple-input multiple output-(MIMOs) based scheme with limited coordination among neighboring base stations (BSs) is proposed to effectively combat the intercell interference by taking advantage of the degreesoffreedom in the spatial domain. In this scheme, mobile users are required to feedback channel-related information to both serving base station and interfering base station. Furthermore, a chordal distance-based compression scheme is introduced to reduce the feedback overhead. The performance of the proposed scheme is investigated through theoretical analysis as well as system level simulations. Both results suggest that the so-called “intercell interference coordination through limited feedback” scheme is a very good candidate for improving the cell-edge user throughput as well as the average cell throughput of the future wireless communication networks.

scholarly journals Outage Performance Analysis of Non-Orthogonal Multiple Access with Time-Switching Energy Harvesting

2019 ◽  
Vol 25 (3) ◽  
pp. 85-91
Author(s):  
Hoang Thien Van ◽  
Hoang-Sy Nguyen ◽  
Thanh-Sang Nguyen ◽  
Van Van Huynh ◽  
Thanh-Long Nguyen ◽  
...  
Keyword(s):  
Energy Harvesting ◽  
Communication Networks ◽  
Multiple Access ◽  
Transmission Rate ◽  
Wireless Communication Networks ◽  
Decode And Forward ◽  
Time Switching ◽  
Outage Performance ◽  
Half Duplex ◽  
The Given

In recent years, although non-orthogonal multiple access (NOMA) has shown its potentials thanks to its ability to enhance the performance of future wireless communication networks, a number of issues emerge related to the improvement of NOMA systems. In this work, we consider a half-duplex (HD) relaying cooperative NOMA network using decode-and-forward (DF) transmission mode with energy harvesting (EH) capacity, where we assume the NOMA destination (D) is able to receive two data symbols in two continuous time slots which leads to the higher transmission rate than traditional relaying networks. To analyse EH, we deploy time-switching (TS) architecture to comprehensively study the optimal transmission time and outage performance at D. In particular, we are going to obtain closed-form expressions for outage probability (OP) with optimal TS ratio for both data symbols with both exact and approximate forms. The given simulation results show that the placement of the relay (R) plays an important role in the system performance.

scholarly journals Intelligent Resource Allocation Method for Wireless Communication Networks Based on Deep Learning Techniques

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Hancheng Hui
Keyword(s):  
Resource Allocation ◽  
Communication Networks ◽  
Base Station ◽  
Resource Control ◽  
Network Throughput ◽  
Base Stations ◽  
Wireless Communication Networks ◽  
Mobile Location ◽  
Small Base ◽  
And Task

In this paper, a deep learning approach is used to conduct an in-depth study and analysis of intelligent resource allocation in wireless communication networks. Firstly, the concepts related to CSCN architecture are discussed and the throughput of small base stations (SBS) in CSCN architecture is analyzed; then, the long short-term memory network (LSTM) model is used to predict the mobile location of users, and the transmission conditions of users are scored based on two conditions, namely, the mobile location of users and whether the small base stations to which users are connected have their desired cache states, and the small base stations select the transmission. The small base station selects several users with optimal transmission conditions based on the scores; then, the concept of game theory is introduced to model the problem of maximizing network throughput as a multi-intelligent noncooperative game problem; finally, a deep augmented learning-based wireless resource allocation algorithm is proposed to enable the small base station to learn autonomously and select channel resources based on the network environment to maximize the network throughput. Simulation results show that the algorithm proposed in this paper leads to a significant improvement in network throughput compared to the traditional random-access algorithm and the algorithm proposed in the literature. In this paper, we apply it to the fine-grained resource control problem of user traffic allocation and find that the resource control technique based on the AC framework can obtain a performance very close to the local optimal solution of a matching-based proportional fair user dual connection algorithm with polynomial-level computational complexity. The resource allocation and task unloading decision policy optimization is implemented, and at the end of the training process, each intelligent body independently performs resource allocation and task unloading according to the current system state and policy. Finally, the simulation results show that the algorithm can effectively improve the quality of user experience and reduce latency and energy consumption.

scholarly journals Technical Note: Novel method for water vapor monitoring using wireless communication networks measurements

2008 ◽  
Vol 8 (3) ◽  
pp. 11673-11684 ◽  
Author(s):  
N. David ◽  
P. Alpert ◽  
H. Messer
Keyword(s):  
Water Vapor ◽  
Wireless Communication ◽  
Communication Networks ◽  
Real Data ◽  
Ground Level ◽  
Weather Conditions ◽  
Technical Note ◽  
Base Stations ◽  
Wireless Communication Networks ◽  
Near Surface

Abstract. We propose a new technique that overcomes the obstacles of the existing methods for monitoring near-surface water vapor, by estimating humidity from data collected through existing wireless communication networks. Weather conditions and atmospheric phenomena affect the electromagnetic channel, causing attenuations to the radio signals. Thus, wireless communication networks are in effect built-in environmental monitoring facilities. The wireless microwave links, used in these networks, are widely deployed by cellular providers for backhaul communication between base stations, a few tens of meters above ground level. As a result, the proposed method can provide moisture observations at high temporal and spatial resolution. Further, the implementation cost is minimal, since the data used are already collected and saved by the cellular operators. In addition – many of these links are installed in areas where access is difficult such as orographic terrain and complex topography. As such, our method enables measurements in places that have been hard to measure in the past, or have never been measured before. We present results from real-data measurements taken from two microwave links used in a backhaul cellular network that show excellent correlation to surface station humidity measurements. The measurements were taken daily in two sites, one in northern Israel (28 measurements), the other in central Israel (29 measurements).The correlation of the microwave link measurements to those of the humidity gauges were 0.9 and 0.82 for the north and central sites, respectively. The RMSE were 20.8% and 33.1% for the northern and central site measurements, respectively.

scholarly journals A heap strategy for UAV deployment issues under mobile terrestrial wireless communication networks

2021 ◽  
Vol 2083 (2) ◽  
pp. 022039
Author(s):  
Yanlin Li
Keyword(s):  
Wireless Communication ◽  
Communication Networks ◽  
Clustering Algorithm ◽  
Clustering Algorithms ◽  
Base Stations ◽  
Wireless Communication Networks ◽  
Coverage Area ◽  
Maximum Coverage ◽  
Mobile Base ◽  
Wireless Connectivity

Abstract Unmanned on-board mobile base stations (MBSs) can more effectively solve wireless connectivity problems in terrestrial communication networks without fixed infrastructure. The purpose of this article is to minimize the number of MBS required to provide wireless coverage for a set of distributed ground terminals (GTs). Traditional clustering algorithms are no longer applicable because each drone has a different coverage area size and the traditional K-Means clustering algorithm has no limit on the number of heaps that can exceed the maximum coverage area of a single drone, making it impossible for a drone to provide services. In response to this problem, the traditional K-Means clustering algorithm is optimized, and the results of the optimized K-Means clustering algorithm are stacked to ensure that each pile has the corresponding drone capability to serve it.

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