scholarly journals Adaptive Multi-state Millimeter Wave Cell Selection Scheme for 5G communication

2018 ◽  
Vol 8 (5) ◽  
pp. 2967 ◽  
Author(s):  
Mothana L Attiah ◽  
Azmi Awang Md Isa ◽  
Zahriladha Zakaria ◽  
Nor Fadzilah Abdullah ◽  
Mahamod Ismail ◽  
...  
Keyword(s):  
Outage Probability ◽  
Millimeter Wave ◽  
System Performance ◽  
Path Loss ◽  
Rain Attenuation ◽  
Mobile User ◽  
Base Stations ◽  
Target Area ◽  
Cell Selection ◽  
Selection Scheme

<p>Millimeter wave bands have been introduced as one of the most promising solutions to alleviate the spectrum secrecy in the upcoming future cellular technology (5G) due the enormous amount of raw bandwidth available in these bands. However, the inherent propagation characteristics of mmWave frequencies could impose new challenges i.e. higher path loss, atmospheric absorption, and rain attenuation which in turn increase the outage probability and hence, degrading the overall system performance. Therefore, in this paper, a novel flexible scheme is proposed namely Adaptive Multi-State MmWave Cell Selection (AMSMC-S) through adopting three classes of mmWave base stations, able to operate at various mmWave carrier frequencies (73, 38 and 28 GHz). Two mmWave cellular Grid-Based cell deployment scenarios have been implemented with two inter-site-distances 200 m and 300 m, corresponding to target area of (2.1 km2) and (2.2 km2). The maximum SINR value at the user equipment (UE) is taken in to consideration to enrich the mobile user experience. Numerical results show an improvement of overall system performance, where the outage probability reduced significantly to zero while maintaining an acceptable performance of the 5G systems with approximately more than 50% of the mobile stations with more than 1Gbps data rate. </p>

scholarly journals Review of Recent Phased Arrays for Millimeter-Wave Wireless Communication

Sensors ◽  
2018 ◽  
Vol 18 (10) ◽  
pp. 3194 ◽  
Author(s):  
Aqeel Naqvi ◽  
Sungjoon Lim
Keyword(s):  
Wireless Communication ◽  
Millimeter Wave ◽  
Communication Systems ◽  
Phased Arrays ◽  
Path Loss ◽  
Directional Antennas ◽  
Base Stations ◽  
Wireless Communication Systems ◽  
Data Traffic ◽  
System Architectures

Owing to the rapid growth in wireless data traffic, millimeter-wave (mm-wave) communications have shown tremendous promise and are considered an attractive technique in fifth-generation (5G) wireless communication systems. However, to design robust communication systems, it is important to understand the channel dynamics with respect to space and time at these frequencies. Millimeter-wave signals are highly susceptible to blocking, and they have communication limitations owing to their poor signal attenuation compared with microwave signals. Therefore, by employing highly directional antennas, co-channel interference to or from other systems can be alleviated using line-of-sight (LOS) propagation. Because of the ability to shape, switch, or scan the propagating beam, phased arrays play an important role in advanced wireless communication systems. Beam-switching, beam-scanning, and multibeam arrays can be realized at mm-wave frequencies using analog or digital system architectures. This review article presents state-of-the-art phased arrays for mm-wave mobile terminals (MSs) and base stations (BSs), with an emphasis on beamforming arrays. We also discuss challenges and strategies used to address unfavorable path loss and blockage issues related to mm-wave applications, which sets future directions.

scholarly journals QoS-Guaranteed Radio Resource Management in LTE-A Co-Channel Networks with Dual Connectivity

2019 ◽  
Vol 9 (15) ◽  
pp. 3018 ◽  
Author(s):  
Ren-Hung Hwang ◽  
Min-Chun Peng ◽  
Kai-Chung Cheng
Keyword(s):  
Transfer Rate ◽  
Data Transfer ◽  
Base Stations ◽  
Cell Selection ◽  
Data Transfer Rate ◽  
Selection Scheme ◽  
Cell Edge ◽  
Q Learning ◽  
Dual Connectivity

Dual connectivity (DC) was first proposed in 3GPP Release 12 which allows one piece of user equipment (UE) to connect to two base stations in heterogeneous networks (HetNet) at the same time, to increase the flexibility of resource utilization. DC has been further extended to multiple connectivity in 5G New Radio (NR). On the other hand, different UE tends to have different bandwidth requirements. Thus, in DC, one of the challenging issues is how to integrate resources from two base stations to enhance the quality of service (QoS) as well as the data transfer rate of each UE. In this paper, we proposed novel resource management mechanisms to improve the QoS of UE in the co-channel dual connectivity network. In terms of resource allocation, we designed the (MTS) which, in principle, allocates a resource block to the UE with the best channel quality while considering the issues of intercell resource allocation and the QoS requirement of each UE. In order to balance the load of different cells, we designed a novel cell selection scheme based on the HetNet Congestion Indicator (HCI) which considers not only the signal quality of UE but also the remaining resources of each base station. To improve the QoS of cell edge UE, cell range expansion (CRE) and the Almost Blank Subframe (ABS) were proposed in 3GPP. In this paper, based on Q-learning, we designed an adaptive mechanism which dynamically adjusts the ABS ratio according to the network condition to improve resource utilization. Our simulation results showed that our MTS scheduler was able to achieve a 31.44% higher data rate than the Proportional Fairness Scheduler; our HCI cell selection scheme yielded a 2.98% higher data rate than the signal-to-interference plus noise ratio (SINR) cell selection scheme; the QoS satisfaction rate of our Q-learning dynamic ABS scheme was 4.06% higher than that of the Static ABS scheme. Finally, for the cell edge users who often suffer poor data transfer rate, by integrating the mechanisms of DC, CRE, and ABS, our experimental results showed that the QoS satisfaction ratio of cell edge UEs could be improved by 10.76% as compared to the single connectivity and no ABS situation.

scholarly journals Performance Analysis of Group Selection in UAV Networks with Backhaul-Aware Biasing

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Shusheng Wang ◽  
Yuanyuan Du ◽  
Hongtao Zhang
Keyword(s):  
Outage Probability ◽  
System Performance ◽  
Stochastic Geometry ◽  
Group Selection ◽  
Reference Signal ◽  
Cell Group ◽  
Cell Selection ◽  
Wireless Backhaul ◽  
Bias Factor ◽  
Major Bottleneck

The limited wireless backhaul capacity has become the major bottleneck for UAV communications, while in existing researches of UAV networks, the relation between cell selection and backhaul capacity has not been modeled. This paper proposes cell group selection with backhaul-aware biasing for UAV networks and analyzes system performance by deriving the rate outage probability via stochastic geometry, where the user’s maximum data rate is constrained by backhaul capacity. Specifically, cell group selection is no longer distance-based and considered with backhaul capacity bias factor, where UAVs with higher backhaul capacity will have a larger bias factor to match the backhaul variance. In addition, the dynamic UAV group is organized with the N largest bias reference signal receiving power (BRSRP), where users can utilize the diversity gain by adjusting serving UAV dynamically as the channel conditions change. Analytical results show that the outage probability is decreased by 58% when cell group size N = 3 and UAV optimal density λ u = 600 / k m 2 when UAV height h = 150   m .

scholarly journals User selection protocol in DF cooperative networks with hybrid TSR-PSR protocol based full-duplex energy harvesting over rayleigh fading channel: system performance analysis

2019 ◽  
Vol 13 (2) ◽  
pp. 534
Author(s):  
Phu Tran Tin ◽  
Le Anh Vu ◽  
Tan N. Nguyen ◽  
Thanh-Long Nguyen
Keyword(s):  
Energy Harvesting ◽  
Outage Probability ◽  
System Performance ◽  
Full Duplex ◽  
Closed Form Expression ◽  
Power Splitting ◽  
User Selection ◽  
Selection Scheme ◽  
Selection Protocol ◽  
Probability System

<span>Cooperative communication has been recently proposed in wireless communication systems for exploring the inherent spatial diversity in relay channels. In this work, we investigate the system performance of the energy harvesting full-duplex (FD) decode-and-forward (DF) hybrid time switching-power splitting relaying TSR-PSR (TPSR) protocol relaying network. In the selection scheme, the best user selection protocol is proposed and investigated. Mainly we derive the closed-form expression for the outage probability, system throughput and the symbol error rate (SER) of the system. Numerical results are also presented by the Monte Carlo simulation to validate the theoretical analysis in connection with the all possible parameters in the comparison between TSPR, TSR and PSR cases. The research results show that TPSR case is better than the others in term of outage probability and SER.</span>

scholarly journals An Adaptive Cell Selection Scheme for 5G Heterogeneous Ultra-Dense Networks

IEEE Access ◽  
2021 ◽  
Vol 9 ◽  
pp. 64224-64240
Author(s):  
Ibtihal Ahmed Alablani ◽  
Mohammed Amer Arafah
Keyword(s):  
Cell Selection ◽  
Selection Scheme ◽  
Dense Networks

scholarly journals Survey of Millimeter-Wave Propagation Measurements and Models in Indoor Environments

Electronics ◽  
2021 ◽  
Vol 10 (14) ◽  
pp. 1653
Author(s):  
Ahmed Al-Saman ◽  
Michael Cheffena ◽  
Olakunle Elijah ◽  
Yousef A. Al-Gumaei ◽  
Sharul Kamal Abdul Rahim ◽  
...  
Keyword(s):  
Millimeter Wave ◽  
Measurement Techniques ◽  
Path Loss ◽  
Delay Spread ◽  
Indoor Environments ◽  
Future Trends ◽  
Signal Loss ◽  
Indoor Wireless ◽  
The Future ◽  
Future Demands

The millimeter-wave (mmWave) is expected to deliver a huge bandwidth to address the future demands for higher data rate transmissions. However, one of the major challenges in the mmWave band is the increase in signal loss as the operating frequency increases. This has attracted several research interests both from academia and the industry for indoor and outdoor mmWave operations. This paper focuses on the works that have been carried out in the study of the mmWave channel measurement in indoor environments. A survey of the measurement techniques, prominent path loss models, analysis of path loss and delay spread for mmWave in different indoor environments is presented. This covers the mmWave frequencies from 28 GHz to 100 GHz that have been considered in the last two decades. In addition, the possible future trends for the mmWave indoor propagation studies and measurements have been discussed. These include the critical indoor environment, the roles of artificial intelligence, channel characterization for indoor devices, reconfigurable intelligent surfaces, and mmWave for 6G systems. This survey can help engineers and researchers to plan, design, and optimize reliable 5G wireless indoor networks. It will also motivate the researchers and engineering communities towards finding a better outcome in the future trends of the mmWave indoor wireless network for 6G systems and beyond.

scholarly journals A Tutorial on Optical Feeding of Millimeter-Wave Phased Array Antennas for Communication Applications

2015 ◽  
Vol 2015 ◽  
pp. 1-22 ◽  
Author(s):  
Ivan Aldaya ◽  
Gabriel Campuzano ◽  
Gerardo Castañón ◽  
Alejandro Aragón-Zavala
Keyword(s):  
Millimeter Wave ◽  
High Speed ◽  
Phased Array ◽  
Path Loss ◽  
High Gain ◽  
Interference Avoidance ◽  
Amplitude Control ◽  
Phased Array Antennas ◽  
Array Antennas ◽  
The Impact

Given the interference avoidance capacity, high gain, and dynamical reconfigurability, phased array antennas (PAAs) have emerged as a key enabling technology for future broadband mobile applications. This is especially important at millimeter-wave (mm-wave) frequencies, where the high power consumption and significant path loss impose serious range constraints. However, at mm-wave frequencies the phase and amplitude control of the feeding currents of the PAA elements is not a trivial issue because electrical beamforming requires bulky devices and exhibits relatively narrow bandwidth. In order to overcome these limitations, different optical beamforming architectures have been presented. In this paper we review the basic principles of phased arrays and identify the main challenges, that is, integration of high-speed photodetectors with antenna elements and the efficient optical control of both amplitude and phase of the feeding current. After presenting the most important solutions found in the literature, we analyze the impact of the different noise sources on the PAA performance, giving some guidelines for the design of optically fed PAAs.

scholarly journals Genetic Algorithm-Based Beam Refinement for Initial Access in Millimeter Wave Mobile Networks

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Hao Guo ◽  
Behrooz Makki ◽  
Tommy Svensson
Keyword(s):  
Genetic Algorithm ◽  
Millimeter Wave ◽  
Mobile Networks ◽  
System Performance ◽  
Multiple Input Multiple Output ◽  
Hardware Impairments ◽  
Mimo Networks ◽  
Multiple Input ◽  
Input Multiple Output ◽  
High Carrier

Initial access (IA) is identified as a key challenge for the upcoming 5G mobile communication system operating at high carrier frequencies, and several techniques are currently being proposed. In this paper, we extend our previously proposed efficient genetic algorithm- (GA-) based beam refinement scheme to include beamforming at both the transmitter and the receiver and compare the performance with alternative approaches in the millimeter wave multiuser multiple-input-multiple-output (MU-MIMO) networks. Taking the millimeter wave communications characteristics and various metrics into account, we investigate the effect of different parameters such as the number of transmit antennas/users/per-user receive antennas, beamforming resolutions, and hardware impairments on the system performance employing different beam refinement algorithms. As shown, our proposed GA-based approach performs well in delay-constrained networks with multiantenna users. Compared to the considered state-of-the-art schemes, our method reaches the highest service outage-constrained end-to-end throughput with considerably less implementation complexity. Moreover, taking the users’ mobility into account, our GA-based approach can remarkably reduce the beam refinement delay at low/moderate speeds when the spatial correlation is taken into account. Finally, we compare the cases of collaborative users and noncollaborative users and evaluate their difference in system performance.

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