scholarly journals RESULTS AND TOOLS FOR EVALUATING THE EFFECTIVENESS OF FOCUSING SYSTEMS TO IMPROVE ACCESSIBILITY IN WIRELESS NETWORKS

2019 ◽  
pp. 90-103
Author(s):  
Volodymyr Astapenya ◽  
Volodymyr Sokolov ◽  
Mahyar TajDini
Keyword(s):  
Wireless Networks ◽  
Mimo Systems ◽  
Mutual Influence ◽  
Metal Plate ◽  
Spectral Structure ◽  
State Control ◽  
Autonomous Element ◽  
Wireless Users ◽  
Objective Control ◽  
Limited Frequency

The widespread use of wireless technologies leads to an ever-increasing number of users and permanently functioning devices. However, the growth of the number of wireless users in a limited space and a limited frequency range leads to an increase in their mutual influence, which ultimately affects the throughput of wireless channels and even the performance of the system as a whole. The article presents the statistics and tendencies of the distribution of wireless networks of the IEEE 802.11 standard systems, as well as analyzes the main problems that arise during the expansion of their use. Substantiation and choice of ways to overcome these difficulties largely depends on the objective control of radiation parameters of access points and subscriber funds in a particular environment. The review of the state control facilities provided by the developers of the equipment is presented, and author's variants of experimental measuring complexes are offered, allowing to control signal and information parameters of Wi-Fi systems. The experimental results obtained with the use of the indicated means, obtained using the accelerating metal-plate lens as an additional autonomous element for focusing the field, including for MIMO systems, the effect of the accelerating metal-plate lens on the spatial distribution of the field, on the spectral structure of the signal are presented. In addition, polarization effects were investigated. Possible ways to further increase the availability, integrity of information and energy efficiency of wireless access systems are discussed. The authors propose simpler and less costly options for increasing the direction of radiation on the basis of an accelerating metal-plate lens, experimentally tested, as well as the use of zone zoning on the path of the computer.

scholarly journals Research of antenna complexes using chiral metamaterials and fractal geometry of radiators for MIMO systems

2021 ◽  
Vol 23 (4) ◽  
pp. 97-110
Author(s):  
Andrey N. Bespalov ◽  
Alexander L. Buzov ◽  
Dmitry S. Klyuev ◽  
Anatoly M. Neshcheret
Keyword(s):  
Spectral Efficiency ◽  
Fractal Geometry ◽  
Software Package ◽  
Mimo Systems ◽  
Mutual Influence ◽  
Fractal Structures ◽  
Chiral Metamaterials ◽  
Sierpinski Triangle ◽  
Electrodynamic Modeling ◽  
Complete Matrix

This article is devoted to the study of the possibilities of increasing spectral efficiency in MIMO systems by using antennas with substrates of biisotropic and bianisotropic chiral metamaterials and various types of fractal emitters, in particular, fractal structures in the form of a Sierpinski triangle, Koch and Gilbert curves, as well as a dipole triangular antenna of complex configuration FRM. The spectral efficiency was calculated by using one of the variations of the Shannon formula, which includes a complete matrix of Z-parameters. In turn, this matrix was determined using the software package of electrodynamic modeling. It is shown that the use of such antennas with the fractal geometry of the emitters located on chiral substrates reduces the mutual influence between the emitters, and, in turn, increases the spectral efficiency in several frequency ranges compared to traditional solutions.

scholarly journals Massive MIMO wireless networks: an overview

2021 ◽  
Author(s):  
Noha Hassan ◽  
Xavier N. Fernando
Keyword(s):  
Wireless Networks ◽  
Massive Mimo ◽  
Mimo Systems ◽  
Multiple Input Multiple Output ◽  
Heterogeneous Systems ◽  
Mimo Networks ◽  
Wireless Broadband ◽  
Input Multiple Output ◽  
Processing Techniques ◽  
Linear Algorithms

Massive multiple-input-multiple-output (MIMO) systems use few hundred antennas to simultaneously serve large number of wireless broadband terminals. It has been incorporated into standards like long term evolution (LTE) and IEEE802.11 (Wi-Fi). Basically, the more the antennas, the better shall be the performance. Massive MIMO systems envision accurate beamforming and decoding with simpler and possibly linear algorithms. However, efficient signal processing techniques have to be used at both ends to overcome the signaling overhead complexity. There are few fundamental issues about massive MIMO networks that need to be better understood before their successful deployment. In this paper, we present a detailed review of massive MIMO homogeneous, and heterogeneous systems, highlighting key system components, pros, cons, and research directions. In addition, we emphasize the advantage of employing millimeter wave (mmWave) frequency in the beamforming, and precoding operations in single, and multi-tier massive MIMO systems. Keywords: 5G wireless networks; massive MIMO; linear precoding; encoding; channel estimation; pilot contamination; beamforming; HetNets

scholarly journals Massive MIMO wireless networks: an overview

2021 ◽  
Author(s):  
Noha Hassan ◽  
Xavier N. Fernando
Keyword(s):  
Wireless Networks ◽  
Massive Mimo ◽  
Mimo Systems ◽  
Multiple Input Multiple Output ◽  
Heterogeneous Systems ◽  
Mimo Networks ◽  
Wireless Broadband ◽  
Input Multiple Output ◽  
Processing Techniques ◽  
Linear Algorithms

Massive multiple-input-multiple-output (MIMO) systems use few hundred antennas to simultaneously serve large number of wireless broadband terminals. It has been incorporated into standards like long term evolution (LTE) and IEEE802.11 (Wi-Fi). Basically, the more the antennas, the better shall be the performance. Massive MIMO systems envision accurate beamforming and decoding with simpler and possibly linear algorithms. However, efficient signal processing techniques have to be used at both ends to overcome the signaling overhead complexity. There are few fundamental issues about massive MIMO networks that need to be better understood before their successful deployment. In this paper, we present a detailed review of massive MIMO homogeneous, and heterogeneous systems, highlighting key system components, pros, cons, and research directions. In addition, we emphasize the advantage of employing millimeter wave (mmWave) frequency in the beamforming, and precoding operations in single, and multi-tier massive MIMO systems. Keywords: 5G wireless networks; massive MIMO; linear precoding; encoding; channel estimation; pilot contamination; beamforming; HetNets

scholarly journals Scheduling for Multi-User Multi-Input Multi-Output Wireless Networks with Priorities and Deadlines

2019 ◽  
Vol 11 (8) ◽  
pp. 172
Author(s):  
Li-on Raviv ◽  
Amir Leshem
Keyword(s):  
Wireless Networks ◽  
Mimo Systems ◽  
State Of The Art ◽  
Spatial Multiplexing ◽  
Queue Management ◽  
Ample Evidence ◽  
Data Packets ◽  
Time Frequency ◽  
Management Techniques ◽  
Overall Performance

The spectral efficiency of wireless networks can be significantly improved by exploiting spatial multiplexing techniques known as multi-user MIMO. These techniques enable the allocation of multiple users to the same time-frequency block, thus reducing the interference between users. There is ample evidence that user groupings can have a significant impact on the performance of spatial multiplexing. The situation is even more complex when the data packets have priority and deadlines for delivery. Hence, combining packet queue management and beamforming would considerably enhance the overall system performance. In this paper, we propose a combination of beamforming and scheduling to improve the overall performance of multi-user MIMO systems in realistic conditions where data packets have both priority and deadlines beyond which they become obsolete. This method dubbed Reward Per Second (RPS), combines advanced matrix factorization at the physical layer with recently-developed queue management techniques. We demonstrate the merits of the this technique compared to other state-of-the-art scheduling methods through simulations.

Sign in / Sign up

Export Citation Format

Share Document