scholarly journals Design of a Practical and Compact mm-Wave MIMO System with Optimized Capacity and Phased Arrays

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Tommaso Cella ◽  
Pål Orten ◽  
Torbjörn Ekman
Keyword(s):  
Phased Arrays ◽  
Mimo System ◽  
Reflector Antenna ◽  
Line Of Sight ◽  
Single Element ◽  
Rectangular Array ◽  
Link Budget ◽  
The Impact ◽  
Antenna Systems ◽  
Uniform Rectangular Array

In this paper we evaluate the feasibility of short range outdoor mm-wave MIMO links in the 70 GHz portion of the E-band (71–76 GHz). We use phased arrays in order to strongly reduce the impact of the multipath components, thus making the channel mainly line-of-sight (LOS). We design the array using a simple patch as a single element and simulate the performances for a 200 m link and a MIMO system with equal element spacing at the transmitter and the receiver. Each node of the MIMO system consists of a uniform rectangular array (URA) where the single element is a patch antenna, in order to achieve higher gains and narrow beams. Such configuration is much more compact compared to the antennas currently employed for the same bandwidth. We optimize the interelement distances at the transmitter and the receiver and evaluate the capacity achievable with different array sizes. The results show that, for the proposed link budget, capacity up to 29 bit/s/Hz is achievable at a range of 200 m, with practical dimensions. We also show that the beamforming capabilities make the design much more flexible than the single reflector antenna systems. In the last part of the paper, we verify that our antenna can also operate in rainy conditions and longer ranges.

Rekomendasi Arsitektur Jaringan Nirkabel berbasis Hotspot untuk area pedesaan (Studi Kasus Pedesaan Jawa Timur Indonesia)

CYCLOTRON ◽  
2019 ◽  
Vol 2 (2) ◽  
Author(s):  
Sabri Balafif ◽  
Tining Haryanti
Keyword(s):  
Ieee 802.11 ◽  
Wireless Access ◽  
Traffic Load ◽  
Line Of Sight ◽  
User Mobility ◽  
Broadband Wireless Access ◽  
Broadband Wireless ◽  
Internet Users ◽  
Link Budget ◽  
Tier 3

Abstrak— Penelitian ini bertujuan untuk mengetahui pola trafik internet pada beberapa lokasi yang diteliti. Pengamatan dilakukan selama dua belas (12) bulan. Data diolah dengan metode statistika untuk mendapatkan proyeksi pengguna internet dan kebutuhan titik hotspot. Penelitian menghasilkan rekomendasi kebutuhan hotspot dengan mempertimbangkan mobilitas pengguna internet dan countur lokasi. Rekomendasi perangkat berbeda pada tiap lokasi dari sisi geografis dan padatnya area. Line of Sight mempengaruhi kemampuan perangkat dalam memancarkan signal internet.Hasil penelitian menunjukkan terjadinya peningkatan pengguna internet pada hari raya umat Islam, Hal ini diduga karena mayoritas masyarakat pada lokasi tersebut muslim. Proyeksi pelanggan di 300 desa didapatkan minimum penetrasi 36,7% dan maksimal 85.2%. Rekomendasi sejumlah 940 Titik hotspot dengan area bandwith secara statik sebesar 3Mbps (aggregate download dan upload).  Penelitian memperhitungkan Link Budget perangkat backhoul tier 3 dengan frekuensi 24Ghz. Setiap  perangkat dapat menangani rata-rata jumlah device yang terkoneksi secara bersama sejumlah > 200 Device teknologi Wi-Fi (IEEE 802.11). Beban total trafik  > 1,6 GBPS. Rekomendasi Arsitektur  broadband wireless access Berbasis Hotspot Di Jawa Timur yaitu Surabaya 140 lokasi dengan 400 titik hotspot, Mojokerto sejumlah 70 lokasi dengan 210 titik hotspot. Pandaan sejumlah 80 lokasi dengan 240 titik hotspot Malang  43 lokasi dengan 90 titik hotspot.Kata kunci: Broadband Wireless Access, Hotspot, Line Of SightAbstract— This study aims to determine the pattern of internet traffic in several locations in Jawa Indonesia. Observations were made for twelve (12) months. Data is processed using statistical methods to obtain projections of internet users and hotspot needs. This study produces recommendations for hotspot needs by considering internet user mobility and location contours. Device recommendations vary by location in terms of geography and crowded areas. Line of Sight affects the ability of the device to emit internet signals. The results showed an increase in internet users on Muslim holidays. Projected customers in 300 villages have a minimum penetration of 36.7% and a maximum of 85.2%. The recommended number of 940 hotspots with a static area of 3Mbps (download aggregate and upload). This study takes into account the tier 3 Link Budget backhoul device with a frequency of 24Ghz. Each device can handle the average number of devices that are connected together by> 200 Wi-Fi technology devices (IEEE 802.11). Total traffic load> 1.6 GBPS. Architectural recommendations for broadband wireless access based on hotspots in East Java, Surabaya, 140 locations with 400 hotspots, Mojokerto with 70 locations with 210 hotspots. Pandaan a total of 80 locations with 240 Malang hotspots 43 locations with 90 hotspots Keywords: Broadband Wireless Access, Hotspot, Line Of Sight

scholarly journals Out of sight, out of mind? The impact of correlated clustering in substructure lensing

2021 ◽  
Author(s):  
Alexandres Lazar ◽  
James S Bullock ◽  
Michael Boylan-Kolchin ◽  
Robert Feldmann ◽  
Onur Çatmabacak ◽  
...  
Keyword(s):  
Dark Matter ◽  
Principal Axis ◽  
Major Axis ◽  
Line Of Sight ◽  
Gravitational Lenses ◽  
Local Clustering ◽  
Analytic Expression ◽  
Halo Masses ◽  
The Impact

Abstract A promising route for revealing the existence of dark matter structures on mass scales smaller than the faintest galaxies is through their effect on strong gravitational lenses. We examine the role of local, lens-proximate clustering in boosting the lensing probability relative to contributions from substructure and unclustered line-of-sight (LOS) haloes. Using two cosmological simulations that can resolve halo masses of Mhalo ≃ 109 M⊙ (in a simulation box of length Lbox ∼ 100 Mpc) and 107 M⊙ (Lbox ∼ 20 Mpc), we demonstrate that clustering in the vicinity of the lens host produces a clear enhancement relative to an assumption of unclustered haloes that persists to >20 Rvir. This enhancement exceeds estimates that use a two-halo term to account for clustering, particularly within 2 − 5 Rvir. We provide an analytic expression for this excess, clustered contribution. We find that local clustering boosts the expected count of 109 M⊙ perturbing haloes by ${\sim }35{{\ \rm per\ cent}}$ compared to substructure alone, a result that will significantly enhance expected signals for low-redshift (zl ≃ 0.2) lenses, where substructure contributes substantially compared to LOS haloes. We also find that the orientation of the lens with respect to the line of sight (e.g. whether the line of sight passes through the major axis of the lens) can also have a significant effect on the lensing signal, boosting counts by an additional $\sim 50{{\ \rm per\ cent}}$ compared to a random orientations. This could be important if discovered lenses are biased to be oriented along their principal axis.

scholarly journals The impact of line-of-sight structures on measuring H0 with strong lensing time delays

2021 ◽  
Vol 504 (2) ◽  
pp. 2224-2234
Author(s):  
Nan Li ◽  
Christoph Becker ◽  
Simon Dye
Keyword(s):  
Time Delays ◽  
Line Of Sight ◽  
Lens Model ◽  
Local Universe ◽  
Significant Discrepancy ◽  
Turn On ◽  
Strong Lensing ◽  
Systematic Effects ◽  
The Impact ◽  
Realistic Line

ABSTRACT Measurements of the Hubble–Lemaitre constant from early- and local-Universe observations show a significant discrepancy. In an attempt to understand the origin of this mismatch, independent techniques to measure H0 are required. One such technique, strong lensing time delays, is set to become a leading contender amongst the myriad methods due to forthcoming large strong lens samples. It is therefore critical to understand the systematic effects inherent in this method. In this paper, we quantify the influence of additional structures along the line of sight by adopting realistic light-cones derived from the cosmoDC2 semi-analytical extragalactic catalogue. Using multiple-lens plane ray tracing to create a set of simulated strong lensing systems, we have investigated the impact of line-of-sight structures on time-delay measurements and in turn, on the inferred value of H0. We have also tested the reliability of existing procedures for correcting for line-of-sight effects. We find that if the integrated contribution of the line-of-sight structures is close to a uniform mass sheet, the bias in H0 can be adequately corrected by including a constant external convergence κext in the lens model. However, for realistic line-of-sight structures comprising many galaxies at different redshifts, this simple correction overestimates the bias by an amount that depends linearly on the median external convergence. We therefore conclude that lens modelling must incorporate multiple-lens planes to account for line-of-sight structures for accurate and precise inference of H0.

scholarly journals Coalescence Dynamics of Acoustically Levitated Droplets

Micromachines ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 343 ◽  
Author(s):  
Koji Hasegawa ◽  
Ayumu Watanabe ◽  
Akiko Kaneko ◽  
Yutaka Abe
Keyword(s):  
Sound Pressure ◽  
Phased Array ◽  
Phased Arrays ◽  
Industrial Applications ◽  
Acoustic Levitation ◽  
Droplet Dynamics ◽  
Levitated Droplets ◽  
Ultrasonic Phased Array ◽  
Velocity Information ◽  
The Impact

The contactless coalescence of a droplet is of paramount importance for physical and industrial applications. This paper describes a coalescence method to be used mid-air via acoustic levitation using an ultrasonic phased array system. Acoustic levitation using ultrasonic phased arrays provides promising lab-on-a-drop applications, such as transportation, coalescence, mixing, separation, evaporation, and extraction in a continuous operation. The mechanism of droplet coalescence in mid-air may be better understood by experimentally and numerically exploring the droplet dynamics immediately before the coalescence. In this study, water droplets were experimentally levitated, transported, and coalesced by controlled acoustic fields. We observed that the edges of droplets deformed and attracted each other immediately before the coalescence. Through image processing, the radii of curvature of the droplets were quantified and the pressure difference between the inside and outside a droplet was simulated to obtain the pressure and velocity information on the droplet’s surface. The results revealed that the sound pressure acting on the droplet clearly decreased before the impact of the droplets. This pressure on the droplets was quantitatively analyzed from the experimental data. Our experimental and numerical results provide deeper physical insights into contactless droplet manipulation for futuristic lab-on-a-drop applications.

scholarly journals Impact of accelerometer based in physical layer wireless networks

2018 ◽  
Vol 7 (2.5) ◽  
pp. 15
Author(s):  
Zuhanis Mansor ◽  
Muhammad Khairulanwar bin Zulkafli
Keyword(s):  
Wireless Communication ◽  
Landscape Position ◽  
Line Of Sight ◽  
Noise Power ◽  
Signal Power ◽  
Propagation Channel ◽  
Signal To Noise ◽  
Downlink Throughput ◽  
The Impact ◽  
Non Line Of Sight

The initial deployments of antenna in the handset consist of fixed non-rotated antenna for transmitting and receiving the signal in the wireless communication scenario. However, link correlation at the UE shows very bad performance when the handset rotates in landscape position. This paper evaluates the impact of accelerometer on the downlink propagation channel of 3G smartphone for non-line-of-sight links. The performance average received signal power is studied for user equipment. Results show that the exploitation of an accelerometer provide better performance in terms of received signal power when the handset rotated from portrait to landscape position. It can be concluded that the deployment of accelerometer can be used to improve existing 3G smartphone received signal. Results also indicate that accelerometer can be used to improve downlink throughput since the signal-to-noise-power is increased by approximately 16%.

scholarly journals MMSE-NP-RISIC-Based Channel Equalization for MIMO-SC-FDE Troposcatter Communication Systems

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Zedong Xie ◽  
Xihong Chen ◽  
Xiaopeng Liu ◽  
Yu Zhao
Keyword(s):  
Interference Cancellation ◽  
Communication Systems ◽  
Intersymbol Interference ◽  
Mimo System ◽  
Multiple Input Multiple Output ◽  
Channel Equalization ◽  
Single Input Single Output ◽  
Single Carrier ◽  
Single Output ◽  
The Impact

The impact of intersymbol interference (ISI) on single-carrier frequency-domain equalization with multiple input multiple output (MIMO-SC-FDE) troposcatter communication systems is severe. Most of the channel equalization methods fail to solve it completely. In this paper, given the disadvantages of the noise-predictive (NP) MMSE-based and the residual intersymbol interference cancellation (RISIC) equalization in the single input single output (SISO) system, we focus on the combination of both equalization schemes mentioned above. After extending both of them into MIMO system for the first time, we introduce a novel MMSE-NP-RISIC equalization method for MIMO-SC-FDE troposcatter communication systems. Analysis and simulation results validate the performance of the proposed method in time-varying frequency-selective troposcatter channel at an acceptable computational complexity cost.

scholarly journals Short-term surface ice motion variations measured with a ground-based portable real aperture radar interferometer

2011 ◽  
Vol 57 (201) ◽  
pp. 53-60 ◽  
Author(s):  
Patrick Riesen ◽  
Tazio Strozzi ◽  
Andreas Bauder ◽  
Andreas Wiesmann ◽  
Martin Funk
Keyword(s):  
Line Of Sight ◽  
Interferometric Imaging ◽  
Short Term ◽  
Glacier Surface ◽  
Fast Acquisition ◽  
Surface Ice ◽  
The Impact ◽  
Real Aperture Radar ◽  
Aperture Radar

AbstractWe report measurements using a portable real aperture radar (Gamma Portable Radar Interferometer (GPRI)) for interferometric imaging of the surface ice motion on Gornergletscher, Switzerland, during the drainage of the adjacent ice-marginal lake Gornersee. The GPRI tracked the surface ice motion in line of sight over an area of ∼3 km2 down-glacier of Gornersee almost continuously during the drainage event. The displacement maps derived from the acquired interferograms capture the spatial distribution of the surface ice motion. Due to fast acquisition times of the microwave images, the GPRI was able to record sub-daily variations of the ice displacements, most likely caused by the impact of the Gornersee drainage on the ice motion of Gornergletscher. In situ point measurements of the ice displacement agree reasonably well with the results obtained by the GPRI and highlight the use of the GPRI for high-resolution measurements of glacier surface ice motion.

scholarly journals The Impact of CN Line Profile Measurements on the Cosmic Microwave Background Temperature

1990 ◽  
Vol 139 ◽  
pp. 390-391
Author(s):  
M. E. Kaiser ◽  
E. L. Wright
Keyword(s):  
Cosmic Microwave Background ◽  
Line Profile ◽  
Line Of Sight ◽  
High Signal ◽  
Microwave Background ◽  
A Value ◽  
Cosmic Microwave Background Temperature ◽  
Background Temperature ◽  
The Impact ◽  
Cmb Temperature

We present moderate to high signal-to-noise high-resolution (R ≈ 150,000–170,000) optical spectra toward ζ Oph. Gaussian fits to our data indicate a value of the line-width parameter b, of b = 1.4 ± 0.2 km s−1, along this line of sight. When CN is used as an indirect probe of the cosmic microwave background (CMB) temperature, the line profile is used to determine saturation corrections in the line. This affects column density calculations, which are reflected in the excitation temperature. Current measurements of the b-value along this line of sight range from 0.88 ± 0.02 km s−1 (Crane et al. 1986) to 1.3 ± 0.1 km s−1 (Hegyi, Traub, and Carleton 1972). The extreme range of these b-values yield saturation corrections to the CMB temperature that differ by 0.05 K, which is equal to the quoted precision of current measurements. Preliminary analysis of observations toward HD 29647 indicate that TCMB = 2.70 ± 0.14 K at 2.64 mm toward this line of sight.

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