scholarly journals 2D-OPC Subarray Structure for Efficient Hybrid Beamforming over Sparse mmWave Channels

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Junhyuk Yoo ◽  
Wonjin Sung ◽  
In-Kyung Kim
Keyword(s):  
Antenna Arrays ◽  
Communication Systems ◽  
Dimensional Space ◽  
Path Loss ◽  
Two Dimensional ◽  
Hardware Cost ◽  
Antenna Structure ◽  
Digital Beamforming ◽  
Trade Offs ◽  
Hybrid Beamforming

Millimeter-wave (mmWave) communication is a key technology of 5G new radio (NR) mobile communication systems. Efficient beamforming using a large antenna array is important to cope with the significant path loss experienced in the mmWave spectrum. The existing fully digital beamforming scheme requires a separate radio frequency (RF) chain for each antenna, which results in an excessive hardware cost and consumption power. Under these circumstances, hybrid beamforming which approaches the performance of fully digital beamforming while reducing the complexity is a promising solution for the mmWave multiuser transmission. By extending the existing hybrid beamforming strategies, this paper proposes a novel architecture which effectively reduces the hardware cost and complexity for large antenna arrays. The proposed scheme includes multiple subarrays in the form of uniform planar array (UPA) which are allowed to be overlapped in the two-dimensional space. The corresponding antenna structure is referred to as the two-dimensional overlapped partially connected (2D-OPC) subarray structure. We evaluate the performance of the proposed scheme to suggest performance-complexity trade-offs in designing versatile antenna arrays for efficient beamforming over the mmWave channel.

scholarly journals Low Complexity Hybrid Precoding Designs for Multiuser mmWave/THz Ultra Massive MIMO Systems

Sensors ◽  
2021 ◽  
Vol 21 (18) ◽  
pp. 6054
Author(s):  
João Pedro Pavia ◽  
Vasco Velez ◽  
Renato Ferreira ◽  
Nuno Souto ◽  
Marco Ribeiro ◽  
...  
Keyword(s):  
Antenna Arrays ◽  
Massive Mimo ◽  
Communication Systems ◽  
High Speed ◽  
Mimo Systems ◽  
Low Complexity ◽  
Phase Shifters ◽  
High Signal ◽  
Design Algorithm ◽  
Trade Offs

Millimeter-wave and terahertz technologies have been attracting attention from the wireless research community since they can offer large underutilized bandwidths which can enable the support of ultra-high-speed connections in future wireless communication systems. While the high signal attenuation occurring at these frequencies requires the adoption of very large (or the so-called ultra-massive) antenna arrays, in order to accomplish low complexity and low power consumption, hybrid analog/digital designs must be adopted. In this paper we present a hybrid design algorithm suitable for both mmWave and THz multiuser multiple-input multiple-output (MIMO) systems, which comprises separate computation steps for the digital precoder, analog precoder and multiuser interference mitigation. The design can also incorporate different analog architectures such as phase shifters, switches and inverters, antenna selection and so on. Furthermore, it is also applicable for different structures, namely fully-connected structures, arrays of subarrays (AoSA) and dynamic arrays of subarrays (DAoSA), making it suitable for the support of ultra-massive MIMO (UM-MIMO) in severely hardware constrained THz systems. We will show that, by using the proposed approach, it is possible to achieve good trade-offs between spectral efficiency and simplified implementation, even as the number of users and data streams increases.

scholarly journals Large Antenna Array with Hybrid Beamforming System for 5G Indoor Communication Network Deployments

2021 ◽  
Author(s):  
Jeyakumar P ◽  
Malar E ◽  
Srinitha S ◽  
Muthuchidambaranathan P ◽  
Arvind Ramesh Ramesh
Keyword(s):  
Antenna Array ◽  
Communication Systems ◽  
Path Loss ◽  
Single Element ◽  
New York University ◽  
Budget Analysis ◽  
Link Budget ◽  
Hybrid Beamforming ◽  
Point To Point ◽  
Large Antenna Array

Abstract The millimeter-wave multiple input multiple output (MIMO) technology is the frontier for 5G communication systems. This work contributes a large antenna array with a limited number of radio frequency chains using the hybrid beamforming (HBF) technique that overcomes extreme path loss in the mmWave system to improve spectral efficiency. The link budget analysis is given for the target data rate of 11.3 Gbps for the point-to-point communication. The number of antenna elements required for the proposed antenna array is determined via link budget analysis. The proposed system includes single element patch antenna configuration, array factor analysis, and beam steering capability. The transmit and receive antenna gain specifications minimize the path loss and improve the system throughput. Combiners and hybrid precoders are designed together in an iterative way for reducing the cost function of the weighted minimum mean squared(WMMSE) error. Simulation results demonstrate that the proposed HBF algorithm performance is highly effective and performs closer to the fully digital beamforming technique. The proposed large antenna array with HBF uses the New York University Simulator (NYUSIM) to perform omnidirectional and directional power delay profile analysis with the most potent power. The proposed large antenna array with HBF methodology provides an optimal approach to indoor point-to-point communication deployments.

scholarly journals Calculating Beamforming Vectors for 5G System Applications

Symmetry ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 2423
Author(s):  
Edgar Dmitriyev ◽  
Eugeniy Rogozhnikov ◽  
Natalia Duplishcheva ◽  
Serafim Novichkov
Keyword(s):  
Antenna Arrays ◽  
Communication Systems ◽  
Path Loss ◽  
Mimo Channel ◽  
Fourth Generation ◽  
Broadband Internet ◽  
Channel Matrix ◽  
Fifth Generation ◽  
Correlated Information ◽  
Value Decomposition

The growing demand for broadband Internet services is forcing scientists around the world to seek and develop new telecommunication technologies. With the transition from the fourth generation to the fifth generation wireless communication systems, one of these technologies is beamforming. The need for this technology was caused by the use of millimeter waves in data transmission. This frequency range is characterized by heavy path loss. The beamforming technology could compensate for this significant drawback. This paper discusses basic beamforming schemes and proposes a model implemented on the basis of QuaDRiGa. The model implements a MIMO channel using symmetrical antenna arrays. In addition, the methods for calculating the antenna weight coefficients based on the channel matrix are compared. The first well-known method is based on the addition of cluster responses to calculate the coefficients. The proposed one uses the singular value decomposition of the channel matrix into clusters to take into account the most correlated information between all clusters when calculating the antenna coefficients. According to the research results, the proposed method for calculating the antenna coefficients allows an increase in the SNR/SINR level by 8–10 dB on the receiving side in the case of analog beamforming with a known channel matrix.

scholarly journals Hybrid Beamforming for Millimeter-Wave Heterogeneous Networks

Electronics ◽  
2019 ◽  
Vol 8 (2) ◽  
pp. 133 ◽  
Author(s):  
Mostafa Hefnawi
Keyword(s):  
Millimeter Wave ◽  
Heterogeneous Networks ◽  
Antenna Arrays ◽  
Large Scale ◽  
Network Capacity ◽  
Base Station ◽  
Antenna Element ◽  
Digital Beamforming ◽  
Hybrid Beamforming ◽  
Cell Base

Heterogeneous networks (HetNets) employing massive multiple-input multiple-output (MIMO) and millimeter-wave (mmWave) technologies have emerged as a promising solution to enhance the network capacity and coverage of next-generation 5G cellular networks. However, the use of traditional fully-digital MIMO beamforming methods, which require one radio frequency (RF) chain per antenna element, is not practical for large-scale antenna arrays, due to the high cost and high power consumption. To reduce the number of RF chains, hybrid analog and digital beamforming has been proposed as an alternative structure. In this paper, therefore, we consider a HetNet formed with one macro-cell base station (MBS) and multiple small-cell base stations (SBSs) equipped with large-scale antenna arrays that employ hybrid analog and digital beamforming. The analog beamforming weight vectors of the MBS and the SBSs correspond to the the best-fixed multi-beams obtained by eigendecomposition schemes. On the other hand, digital beamforming weights are optimized to maximize the receive signal-to-interference-plus-noise ratio (SINR) of the effective channels consisting of the cascade of the analog beamforming weights and the actual channel. The performance is evaluated in terms of the beampatterns and the ergodic channel capacity and shows that the proposed hybrid beamforming scheme achieves near-optimal performance with only four RF chains while requiring considerably less computational complexity.

scholarly journals Initial Access through Beamforming in mmWave

2020 ◽  
Vol 2 (2) ◽  
pp. 92-99
Author(s):  
Ms. Christina G.
Keyword(s):  
Energy Consumption ◽  
Power Consumption ◽  
Antenna Arrays ◽  
Path Loss ◽  
High Energy ◽  
Spatial Multiplexing ◽  
Low Resolution ◽  
Millimetre Wave ◽  
Digital Beamforming ◽  
Front End

Future Wi-Fi, 5G Cellular and millimetre-wave (mmWave) will depend on highly directional links in order to prevail over exuberant path loss experienced in the different bands of frequency. However, in order to establish these type of links, the receiver and transmitter need mutual discovery which will result in high energy consumption and large latency. The proposed work deals with reduction of energy consumption and latency significantly with the help of a fully digital front-end. The digital beamformer will receive the spatial samples within a shot, from all directions. However, in analog front-ends, sampling is allowed for beamforming in one particular direction at a time resulting in the time period in which the mobile is “on” for longer. This will result in an increase in energy consumption by more than four times for the analog front-end when compared with digital front-ends, taking into consideration the antenna arrays’ size. However, from the power consumption point of view, using a fully digital beamforming post beam discovery is not recommended. Hence in order to overcome this drawback, a digital beamformer coupled with a 4-bit A-D convertor with low resolution is proposed. The use of low resolution will decrease the power consumption such that it is in the same zone as that of analog beam forming while it is possible to make use of the fully digital beamforming spatial multiplexing capabilities resulting in improved energy efficiency and reduced discovery latency.

scholarly journals Performance analysis of multi user massive MIMO hybrid beamforming systems at millimeter wave frequency bands

2021 ◽  
Author(s):  
Ravilla Dilli
Keyword(s):  
Wireless Networks ◽  
Millimeter Wave ◽  
Antenna Arrays ◽  
Data Streams ◽  
Research Work ◽  
Path Loss ◽  
Base Station ◽  
Frequency Bands ◽  
Hybrid Beamforming ◽  
Key Enabling Technologies

AbstractMillimeter-wave (mmWave) and massive multi-input–multi-output (mMIMO) communications are the most key enabling technologies for next generation wireless networks to have large available spectrum and throughput. mMIMO is a promising technique for increasing the spectral efficiency of wireless networks, by deploying large antenna arrays at the base station (BS) and perform coherent transceiver processing. Implementation of mMIMO systems at mmWave frequencies resolve the issue of high path-loss by providing higher antenna gains. The motivation for this research work is that mmWave and mMIMO operations will be much more popular in 5G NR, considering the wide deployment of mMIMO in major frequency bands as per 3rd generation partnership project. In this paper, a downlink multi-user mMIMO (MU-mMIMO) hybrid beamforming communication system is designed with multiple independent data streams per user and accurate channel state information. It emphasizes the hybrid precoding at transmitter and combining at receiver of a mmWave MU-mMIMO hybrid beamforming system. Results of this research work give the tradeoff between multiple data streams per user and required number of BS antennas. It strongly recommends for higher number of parallel data streams per user in a mmWave MU-mMIMO systems to achieve higher order throughputs.

On the Classification of Fractal and Non-Fractal Objects in Two-Dimensional Space

2020 ◽  
Vol 14 (6) ◽  
pp. 1232-1239
Author(s):  
P. M. Pustovoit ◽  
E. G. Yashina ◽  
K. A. Pshenichnyi ◽  
S. V. Grigoriev
Keyword(s):  
Dimensional Space ◽  
Two Dimensional

Political Cleavages and Political Parties

2018 ◽  
Author(s):  
Russell J. Dalton
Keyword(s):  
Political Parties ◽  
Dimensional Space ◽  
New Left ◽  
Party Systems ◽  
European Parliament ◽  
Two Dimensional ◽  
Far Right ◽  
Policy Positions ◽  
Cultural Policies ◽  
Policy Choices

This chapter uses the cleavage positions of Candidates to the European Parliament (CEPs) to as representative of their parties’ political positions. Three surveys of CEPs track the evolution of party supply in European party systems. In 1979 parties were primarily aligned along a Left–Right economic cleavage. Gradually new left and Green parties began to compete in elections and crystallized and represented liberal cultural policies. In recent decades new far-right parties arose to represent culturally conservative positions. The cross-cutting cultural cleavage has also prompted many of the established parties to alter their policy positions. In most multiparty systems, political parties now compete in a fully populated two-dimensional space. This increases the supply of policy choices for the voters. The analyses are based on the Candidates to the European Parliament Studies in 1979, 1994, and 2009.

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