scholarly journals Pilot Sequence Design for mmWave Cellular Systems With Relay Stations in the Presence of Blockage

IEEE Access ◽  
2020 ◽  
Vol 8 ◽  
pp. 80454-80467
Author(s):  
Yeong Jun Kim ◽  
Qasim Sultan ◽  
Yong Soo Cho
Keyword(s):  
Cellular Systems ◽  
Sequence Design ◽  
Relay Stations

scholarly journals Sequence Design Technique for Accurate Timing and Cell ID Estimation in Underwater Acoustic Cellular Systems with a High Doppler

Electronics ◽  
2021 ◽  
Vol 10 (19) ◽  
pp. 2413
Author(s):  
Yeong Jun Kim ◽  
Muhammad Asim ◽  
Tae Ho Im ◽  
Yong Soo Cho
Keyword(s):  
Doppler Shift ◽  
Additive White Gaussian Noise ◽  
Cellular Systems ◽  
Joint Estimation ◽  
Sensor Nodes ◽  
Sequence Length ◽  
Design Technique ◽  
Sequence Design ◽  
Underwater Acoustic ◽  
Simulation Results

In underwater acoustic cellular (UWAC) systems, underwater equipment or sensor nodes (UE/SN) should perform downlink synchronisation and a cell search during the initial access stage using the preambles received from adjacent underwater base stations (UWBSs). The UE/SN needs to estimate accurate timing and cell ID (CID) using the received preambles, and synchronise with a serving UWBS, even in high-Doppler environments. In this paper, a sequence design technique for joint estimation of accurate timing and CID in UWAC systems with a high Doppler is proposed to decrease the receiver complexity and processing time. A generalised Zadoff–Chu sequence is proposed for the preamble design. This sequence is decomposed into multiple short sub-sequences to reduce the effect of Doppler shift on the timing and CID estimation. The performance loss caused by the short sequence length is compensated by combining the sub-sequences using the repetition property of the ZC sequence. The properties (autocorrelation and cross-correlation) of the proposed sequence are derived analytically in the presence of Doppler shift and compared with the simulation results. The simulation results reveal that the proposed technique performs better than existing techniques in both additive white Gaussian noise and multipath channels with a high-Doppler. It is concluded that the proposed technique is suitable for accurate timing estimation and CID detection in UWAC systems with a high Doppler.

scholarly journals STEERABLE TOROIDAL BIFOCAL LENS-ARRAY ANTENNA IN 57–64 GHZ RANGE

2019 ◽  
Vol 22 (3) ◽  
pp. 36-47
Author(s):  
Alexander A. Maltsev ◽  
Valentin M. Seleznev ◽  
Alexander S. Rulkov ◽  
Olesya V. Bolkhovskaya
Keyword(s):  
Low Cost ◽  
Antenna System ◽  
Base Station ◽  
Cellular Systems ◽  
Array Antenna ◽  
Lens Antenna ◽  
Lens Array ◽  
Steerable Antenna ◽  
Antenna Systems ◽  
Relay Stations

Introduction. Currently, one of the most promising approaches of the 5th generation mobile wireless systems development is the deployment of heterogeneous networks based on existing LTE cellular systems with large and small cells. The main elements of such networks can be small low cost relay stations equipped with highly directional steerable antenna systems to connect small cells with LTE base station serving macrocell. Objective. Existing solutions are either too expensive or not allowing flexible rearrangement of current information transmission lines. The objective of this work is to develop antenna equipment for low cost relay stations based on simple steerable antenna systems of millimetre wavelength (57-64 GHz), which allow beamsteering in both azimuth and elevation planes. Methods and materials. The developed steerable bifocal lens antenna system is a lens of a special shape made of a high molecular weight polyethylene and integrated with a phased array antenna. A key feature of the designed antenna system is a wide-angle beamsteering in the azimuth plane and ability to adjust the beam in the elevation plane. The calculation of the lens profiles was carried out by means of an approximation of geometrical optics in Matlab, and the main technical characteristics of the lens antenna system were obtained by direct electromagnetic modelling in CST Microwave Studio. Results. The prototype of the steerable bifocal lens-array antenna system is developed and its characteristics are studied. The following technical characteristics are achieved in the 57–64 GHz range: beamsteering in the elevation plane is ±3º, beamsteering in the azimuth plane is ±40º, and antenna gain is from 20 to 27.5 dBi for all angles. Conclusion. It was shown that the developed antenna system can be successfully used as receiving and transmission antenna equipment of small relay stations that transmit information in the frequency range of 57-64 GHz over a distance of 100-300 m.

scholarly journals Doppler-tolerant sequence design for positioning high-speed vehicles in millimeter-wave cellular systems

2021 ◽  
pp. 100358
Author(s):  
Mohammed Saquib Khan ◽  
Chang Hwan Park ◽  
Jingon Joung ◽  
Yong Soo Cho
Keyword(s):  
Millimeter Wave ◽  
High Speed ◽  
Cellular Systems ◽  
Sequence Design

Label-free, mass-sensitive single-molecule imaging using interferometric scattering microscopy

2020 ◽  
Author(s):  
Nikolas Hundt
Keyword(s):  
Single Molecule ◽  
Cellular Systems ◽  
Single Molecule Imaging ◽  
Label Free ◽  
Measurement Sensitivity ◽  
Mass Distributions ◽  
Quantitative Measurements ◽  
Contrast Mechanism ◽  
Cellular Components ◽  
Scattering Signal

Abstract Single-molecule imaging has mostly been restricted to the use of fluorescence labelling as a contrast mechanism due to its superior ability to visualise molecules of interest on top of an overwhelming background of other molecules. Recently, interferometric scattering (iSCAT) microscopy has demonstrated the detection and imaging of single biomolecules based on light scattering without the need for fluorescent labels. Significant improvements in measurement sensitivity combined with a dependence of scattering signal on object size have led to the development of mass photometry, a technique that measures the mass of individual molecules and thereby determines mass distributions of biomolecule samples in solution. The experimental simplicity of mass photometry makes it a powerful tool to analyse biomolecular equilibria quantitatively with low sample consumption within minutes. When used for label-free imaging of reconstituted or cellular systems, the strict size-dependence of the iSCAT signal enables quantitative measurements of processes at size scales reaching from single-molecule observations during complex assembly up to mesoscopic dynamics of cellular components and extracellular protrusions. In this review, I would like to introduce the principles of this emerging imaging technology and discuss examples that show how mass-sensitive iSCAT can be used as a strong complement to other routine techniques in biochemistry.

Sign in / Sign up

Export Citation Format

Share Document