scholarly journals Modeling of Downlink Interference in Massive MIMO 5G Macro-Cell

Sensors ◽  
2021 ◽  
Vol 21 (2) ◽  
pp. 597
Author(s):  
Kamil Bechta ◽  
Cezary Ziółkowski ◽  
Jan M. Kelner ◽  
Leszek Nowosielski
Keyword(s):  
Power Distribution ◽  
Communication Systems ◽  
Channel Model ◽  
Radio Channel ◽  
Angular Separation ◽  
Simulation Method ◽  
Antenna System ◽  
Propagation Model ◽  
Simulation Results ◽  
The Impact

Multi-beam antenna systems are the basic technology used in developing fifth-generation (5G) mobile communication systems. In practical implementations of 5G networks, different approaches are used to enable a massive multiple-input-multiple-output (mMIMO) technique, including a grid of beams, zero-forcing, or eigen-based beamforming. All of these methods aim to ensure sufficient angular separation between multiple beams that serve different users. Therefore, ensuring the accurate performance evaluation of a realistic 5G network is essential. It is particularly crucial from the perspective of mMIMO implementation feasibility in given radio channel conditions at the stage of network planning and optimization before commercial deployment begins. This paper presents a novel approach to assessing the impact of a multi-beam antenna system on an intra-cell interference level in a downlink, which is important for the accurate modeling and efficient usage of mMIMO in 5G cells. The presented analysis is based on geometric channel models that allow the trajectories of propagation paths to be mapped and, as a result, the angular power distribution of received signals. A multi-elliptical propagation model (MPM) is used and compared with simulation results obtained for a statistical channel model developed by the 3rd Generation Partnership Project (3GPP). Transmission characteristics of propagation environments such as power delay profile and antenna beam patterns define the geometric structure of the MPM. These characteristics were adopted based on the 3GPP standard. The obtained results show the possibility of using the presented novel MPM-based approach to model the required minimum separation angle between co-channel beams under line-of-sight (LOS) and non-LOS conditions, which allows mMIMO performance in 5G cells to be assessed. This statement is justified because for 80% of simulated samples of intra-cell signal-to-interference ratio (SIR), the difference between results obtained by the MPM and commonly used 3GPP channel model was within 2 dB or less for LOS conditions. Additionally, the MPM only needs a single instance of simulation, whereas the 3GPP channel model requires a time-consuming and computational power-consuming Monte Carlo simulation method. Simulation results of intra-cell SIR obtained this way by the MPM approach can be the basis for spectral efficiency maximization in mMIMO cells in 5G systems.

scholarly journals Vehicle-to-Vehicle Radio Channel Characteristics for Congestion Scenario in Dense Urban Region at 5.9 GHz

2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Yishui Shui ◽  
Fang Li ◽  
Junyi Yu ◽  
Wei Chen ◽  
Changzhen Li ◽  
...  
Keyword(s):  
Communication Systems ◽  
Radio Channel ◽  
Average Power ◽  
Urban Region ◽  
Doppler Spectrum ◽  
Small Scale ◽  
Power Delay Profile ◽  
Car Following ◽  
Vehicle To Vehicle ◽  
The Impact

This paper reports the results of a car-following measurement of the wireless propagation channel at 5.9 GHz on a seriously congested urban road in Wuhan, China. The small-scale amplitude-fading distribution was determined to be a Ricean distribution using the Akaike information criterion. This result shows that this car-following scenario can be regarded as a line-of-sight radio channel. Moreover, the statistical K-factor features follow a Gaussian distribution. According to the power delay profile and average power delay profile, we found that street buildings in this dense urban environment contributed to very strong reflection phenomena. The impact of a powerful reflection is analyzed through path loss, delay, and Doppler spreads in the channel statistical properties. In the frequency domain, we observe a U-shape delay-Doppler spectrum that proved that the dense urban scenario consists of scattering channels. All these results are summarized in tabular form that will be useful in the modeling of vehicle-to-vehicle wireless communication systems.

scholarly journals A Combined Method for Predicting the Boron Deposited Mass and the CIPS Risk

2019 ◽  
Vol 2019 ◽  
pp. 1-8
Author(s):  
Shengzhe Li ◽  
Dongmei Yang ◽  
Tengfei Zhang ◽  
Xiaojing Liu
Keyword(s):  
Power Distribution ◽  
Neutron Cross Section ◽  
Local Power ◽  
Combined Method ◽  
Boron Compounds ◽  
The Core ◽  
Simulation Results ◽  
Deposit Model ◽  
Power Distribution Control ◽  
The Impact

CIPS is a shift in the axial power towards the bottom half of the core, also known as axial offset anomaly (AOA), which results from the deposited of corrosion products during an operation. The main reason of CIPS is the solute particles especially boron compounds concentrated inside the porous deposit. The impact of CIPS is that the axial power distribution control may be more difficult and the shutdown margin can be decreased simultaneously. Besides, it also requires estimated critical condition (ECC) calculations to account for the effects of AOA. In this article, thermal-hydraulic subchannel code and boron deposit model have been combined to analyze the CIPS risk. The neutronics codes deal with the generation of homogenized neutron cross section as well as the calculation of local power factor. A simple rod assembly is analyzed with this combined method and simulation results are presented. Simulation results provide the boron hideout amount inside crud deposits and power shapes. The obtained results clearly show the power shape suppression in regions where crud deposits exist, which is a clear indication of CIPS phenomenon. And the CIPS effects on CHF have also been investigated. Result shows a margin of DNBR decrease in the crud case.

Influence of Oriented Perforation Design on Refracture Reorientation: Simulation and Experiment

2018 ◽  
Vol 140 (8) ◽  
Author(s):  
Minhui Qi ◽  
Mingzhong Li ◽  
Tiankui Guo ◽  
Chunting Liu ◽  
Song Gao ◽  
...  
Keyword(s):  
Hydraulic Fracturing ◽  
Large Scale ◽  
Simulation Models ◽  
Fracture Initiation ◽  
Simulation Method ◽  
Induced Stress ◽  
Study Results ◽  
Simulation Results ◽  
Fracturing Experiments ◽  
The Impact

The oriented perforating is the essential technique to guide the refracture reorientation, but the influence of the oriented perforation design on the refracture steering radius is still unclear. In this paper, the factors influencing the refracture reorientation were studied by simulation models and experiments. The effects of initial fracture, well production, and perforations on the refracture initiation and propagation were analyzed. Three-dimensional finite element models were conducted to quantify the impact of perforation depth, density, and azimuth on the refracture. The large-scale three-axis hydraulic fracturing experiments guided by oriented perforations were also carried out to verify the fracture initiation position and propagation pattern of the simulation results. The research results showed that perforations change the near-wellbore induced stress distribution, thus changing the steering radius of the refracture. According to the simulation results, the oriented perforation design has a significant influence on the perforation guidance effect and refracture characteristics. Five hydraulic fracturing experiments proved the influence of perforating parameters on fracture initiation and morphology, which have a right consistency between the simulation results. This paper presents a numerical simulation method for evaluating the influence of the refracture reorientation characteristics under the consideration of multiple prerefracturing induced-stress and put forward the oriented perforation field design suggestions according to the study results.

scholarly journals KAJIAN PENERAPAN ARSITEKTUR HIJAU PADA KANTOR PEMERINTAH KABUPATEN BOYOLALI; Fokus pada Nilai Embodied Energy Bangunan

2017 ◽  
Vol 11 (6) ◽  
pp. 243
Author(s):  
Alifiano Rezka Adi
Keyword(s):  
Simulation Method ◽  
Embodied Energy ◽  
Ground Floor ◽  
Design Recommendations ◽  
Energy Value ◽  
Floor Area ◽  
Green Architecture ◽  
Simulation Results ◽  
Modeling Strategy ◽  
The Impact

Abstract: Green architecture approach comes as a solution of solving the energy and environmental crises. Boyolali regency office became the research object by focusing on the value of embodied energy to determine and evaluate the energy consumed from the manufacturing of the material until the construction phase. This study uses a simulation method with modeling strategy at the masterplan area and the existing area to measure the embodied energy of the buildings. The results showed that the larger of the ground floor area, the greater of the embodied energy value of the building. In addition, a building which has more floors will save the value of the embodied energy compared to a one floor building with the same floor area. The existing condition showed the saving of the embodied energy value by 22.64% towards the masterplan because of its smaller total ground floor area. The impact of the floor area and floor number is used in determining the design recommendations by combining several buildings into one building to reduce the total floor area as well as to convert most buildings into two-story buildings. The simulation results from the proposed recommendation showed the efficiency of the embodied energy value, which is more optimal, by 21,76% towards the existing condition.Keywords: green architecture, embodied energy, office area, energy efficiencyAbstrak: Pendekatan arsitektur hijau hadir sebagai solusi dalam mengatasi permasalahan energi dan lingkungan. Kantor pemerintahan Boyolali dijadikan sebagai objek penelitian dengan berfokus pada nilai embodied energy untuk menentukan dan mengevaluasi energi yang digunakan dari proses pengolahan material bangunan hingga fase konstruksi bangunan. Penelitian menggunakan metode simulasi dengan strategi pemodelan pada masterplan kawasan serta kondisi eksisting kawasan untuk mengukur nilai embodied energy bangunan. Hasil penelitian menunjukkan bahwa semakin besar luas permukaan lantai bangunan, semakin besar nilai embodied energy pada bangunan tersebut. Selain itu, jumlah lantai yang lebih banyak akan menghemat nilai embodied energy jika dibandingkan dengan bangunan satu lantai dengan luas lantai dasar yang sama. Kondisi eksisting menunjukkan penghematan nilai embodied energy sebesar 22,64% terhadap masterplan karena memiliki luas total lantai dasar lebih kecil. Dampak dari luas lantai dasar dan jumlah lantai digunakan dalam menentukan rekomendasi desain dengan menggabungkan beberapa bangunan menjadi satu untuk mengurangi luasan total lantai dasar sekaligus menjadikan bangunan-bangunan yang ada menjadi gedung berlantai dua. Hasil simulasi dari rekomendasi yang diusulkan menunjukkan efisiensi nilai embodied energy yang lebih optimal sebesar 21,76% terhadap kondisi eksisting.Kata kunci: arsitektur hijau, embodied energy, kawasan perkantoran, efisiensi energi

scholarly journals Fast computation of the iteration-based simulation method - case study of non-coherent ask with shadowing

2017 ◽  
Vol 14 (3) ◽  
pp. 415-431 ◽  
Author(s):  
Vladimir Mladenovic ◽  
Sergey Makov ◽  
Yigang Cen ◽  
Miroslav Lutovac
Keyword(s):  
Numerical Methods ◽  
Probability Density ◽  
Communication Systems ◽  
Data Transfer ◽  
Joint Probability ◽  
Simulation Method ◽  
Wireless Communication Systems ◽  
Closed Form Solutions ◽  
The Impact

This article presents a new method of fast symbolic computations of very complex calculations, which are necessary for the analysis, simulation, and design of wireless communication systems using CAS (Computer Algebra System). CAS is applied to formulate hypotheses and define joint probability density functions of certain modulation technique. This is used to prepare for the semi-symbolic calculation to complete specify wireless system by using CAS. We have developed an iteration-based simulation method that aids to solve semisymbolic expressions and gives closed form solutions (with some parameters specified as numbers and some as symbols). So far, they are solved by numerical methods. Students can perform performance analysis and understand the processes in the data transfer. Engineers and researchers may have a better insight into the impact of the important parameters necessary to properly transmit and detect information unlike traditional numerical methods. The main contribution is to obtain solutions for the probability density function, and outage probability where no solution can be obtained using numerical methods. A strong emphasis is placed on very fast calculations that significantly save the time of analysis, simulation, and design.

scholarly journals On the Capacity of Amplitude Modulated Soliton Communication over Long Haul Fibers

Entropy ◽  
2020 ◽  
Vol 22 (8) ◽  
pp. 899
Author(s):  
Yu Chen ◽  
Iman Tavakkolnia ◽  
Alex Alvarado ◽  
Majid Safari
Keyword(s):  
Communication Systems ◽  
Channel Model ◽  
Additive White Gaussian Noise ◽  
Soliton Interaction ◽  
Capacity Limits ◽  
Model Based ◽  
Chi Squared ◽  
Optic Communication ◽  
Capacity Formulation ◽  
The Impact

The capacity limits of fiber-optic communication systems in the nonlinear regime are not yet well understood. In this paper, we study the capacity of amplitude modulated first-order soliton transmission, defined as the maximum of the so-called time-scaled mutual information. Such definition allows us to directly incorporate the dependence of soliton pulse width to its amplitude into capacity formulation. The commonly used memoryless channel model based on noncentral chi-squared distribution is initially considered. Applying a variance normalizing transform, this channel is approximated by a unit-variance additive white Gaussian noise (AWGN) model. Based on a numerical capacity analysis of the approximated AWGN channel, a general form of capacity-approaching input distributions is determined. These optimal distributions are discrete comprising a mass point at zero (off symbol) and a finite number of mass points almost uniformly distributed away from zero. Using this general form of input distributions, a novel closed-form approximation of the capacity is determined showing a good match to numerical results. Finally, mismatch capacity bounds are developed based on split-step simulations of the nonlinear Schro¨dinger equation considering both single soliton and soliton sequence transmissions. This relaxes the initial assumption of memoryless channel to show the impact of both inter-soliton interaction and Gordon–Haus effects. Our results show that the inter-soliton interaction effect becomes increasingly significant at higher soliton amplitudes and would be the dominant impairment compared to the timing jitter induced by the Gordon–Haus effect.

Dual-band (28/38 GHz) MIMO Antenna System for 5G Mobile Communications with Efficient DoA Estimation Algorithm in Noisy Channels

2021 ◽  
Vol 36 (3) ◽  
pp. 282-294
Author(s):  
Asmaa Farahat ◽  
Khlaid Hussein
Keyword(s):  
Mobile Communications ◽  
Communication Systems ◽  
Doa Estimation ◽  
Antenna System ◽  
Dual Band ◽  
Linear Antenna ◽  
Mimo Antenna ◽  
Single Antenna ◽  
Simulation Results ◽  
5G Mobile Communications

In this paper, a dual-band (28/38 GHz) linear antenna arrays of four and eight elements are proposed to work as a MIMO arrays for the 5G communication systems. Each element in the array is a dual-band Yagi-Uda antenna designed to operate at 28 and 38 GHz. The eight-elements array size has a total dimension of 79.4 mm x 9.65 mm excluding the feeding microstrip line. The maximum gain of the array is about 18 dB. The peaks of correlation at matched angles (PCMA) technique is applied to determine the direction of arrival for multiple incoming signals. The effects of phase noise and additive Gaussian noise on the error in the DoA estimation are studied showing good accuracy of the PCMA algorithm. Numerical and experimental investigations are achieved to assess the performance of both the single-element antenna and the eight-element MIMO linear antenna array. It is shown that the simulation results agree with the experimental measurements and both show good performance of the single antenna as well as the MIMO linear array system. The envelope correlation coefficient (ECC) and the diversity gain (DG) are calculated and the results show that the proposed MIMO antenna system is suitable for the forthcoming 5G mobile communications. The radiation patterns for single antenna and four-element array are measured and compared to the electromagnetic simulation results showing good agreement.

Subduction channel vs. orogenic wedge model: numerical simulations, impact of serpentinites and application to the Alps

2020 ◽  
Author(s):  
Lorenzo G. Candioti ◽  
Stefan M. Schmalholz ◽  
Thibault Duretz
Keyword(s):  
Channel Model ◽  
Thermal Relaxation ◽  
Passive Margin ◽  
Crustal Material ◽  
Subduction Channel ◽  
Passive Margins ◽  
Coupled Equations ◽  
Orogenic Wedge ◽  
Simulation Results ◽  
The Impact

<p>In this study, we use a state-of-the-art 2D numerical algorithm solving the standard thermo-mechanically coupled equations of continuum mechanics for slow flowing viscoelastoplastic material to model the evolution of rifting, thermal relaxation and convergence-to-collision of Alpine-type orogens in three stages. (1) A ca. 360 km wide basin that is floored by exhumed mantle and bounded by two conjugate magma-poor hyper-extended passive margins is generated during a 50 Myrs rifting period. An absolute extension velocity of 1 cm/yr is applied. (2) The passive margin system is thermally equilibrated during a subsequent cooling period of 60 Myrs without significant deformation in the lithosphere (no extension velocity). At this stage, we parameterise a serpentinization front on top of the exhumed mantle by replacing the dry peridotitic mantle by serpentinized mantle in one series of simulations. The thermally equilibrated system is used as a self-consistently generated initial configuration for the subsequent period of convergence lasting for 70 Myrs applying an absolute convergence velocity of 1.5 cm/yr. Values for the duration of deformation periods and for deformation velocities are chosen to allow for comparison between simulation results and petrological data from the Central and Western Alps. Density of all materials is either precomputed for characteristic bulk rock compositions and read in from precomputed thermodynamic look-up tables (Perple_X), or calculated during run time via a linearized equation of state (EOS).</p><p> </p><p>We quantify (1) the impact of a serpentinization front of the exhumed mantle on the subduction dynamics by increasing systematically the strength of the serpentinites, (2) the peak pressure and temperature conditions of subducted crustal material from the passive margins of the overriding and subducting plate by tracking pressure (P)-temperature (T)-time (t)-depth (z) paths of selected particles and (3) the driving forces of the system. Last, (4) the impact of metamorphic phase transitions is investigated by parameterising densification of crustal material. We compare the results of simulations in which density is computed as a simple linearized EOS to results of simulations in which density is a more realistic function of P and T using precomputed thermodynamic look-up tables.</p><p> </p><p>We discuss geometric similarities between the simulation results and 2D geodynamic reconstructions from field data, quantify the P-T-t-z-history of selected particles and compare it to P-T-t data obtained from natural rocks. First results indicate that the strength of the serpentinites controls whether the deformation within the orogenic core is driven by buoyancy forces (subduction channel model) or by far-field tectonic forces (orogenic wedge model). There is a transition from subduction channel to orogenic wedge model from low to intermediate strength of the serpentinites.</p>

scholarly journals A TDL Based Non-WSSUS Vehicle-to-Vehicle Channel Model

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Yan Li ◽  
Bo Ai ◽  
Xiang Cheng ◽  
Siyu Lin ◽  
Zhangdui Zhong
Keyword(s):  
Communication Systems ◽  
Delay Line ◽  
Channel Model ◽  
Correlation Coefficients ◽  
Simulation Method ◽  
Wide Sense ◽  
V2v Communication ◽  
Vehicle To Vehicle ◽  
Model And Simulation ◽  
The Relationship

This paper proposes a non-wide-sense-stationary-uncorrelated scattering (WSSUS) channel model for vehicle-to-vehicle (V2V) communication systems. The proposed channel model is based on the tapped-delay line (TDL) structure and considers the correlation between taps both in amplitude and phase. Using the relationship between the correlation coefficients of complex Gaussian, Weibull, and Uniform random variables (RVs), the amplitude and the phase of taps with different delays are modeled as correlated RVs to reflect the non-WSSUS properties of V2V channels. The effectiveness of the proposed channel model and simulation method is validated by the measurements in different scenarios.

scholarly journals Ray-Based Statistical Propagation Modeling for Indoor Corridor Scenarios at 15 GHz

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Qi Wang ◽  
Bo Ai ◽  
Ke Guan ◽  
David W. Matolak ◽  
Ruisi He ◽  
...  
Keyword(s):  
Communication Systems ◽  
Channel Model ◽  
Deterministic Model ◽  
Path Loss ◽  
Propagation Characteristic ◽  
Directional Antennas ◽  
Small Scale ◽  
Delay Spread ◽  
Channel Measurements ◽  
The Impact

According to the demands for fifth-generation (5G) communication systems, high frequency bands (above 6 GHz) need to be adopted to provide additional spectrum. This paper investigates the characteristics of indoor corridor channels at 15 GHz. Channel measurements with a vector network analyzer in two corridors were conducted. Based on a ray-optical approach, a deterministic channel model covering both antenna and propagation characteristic is presented. The channel model is evaluated by comparing simulated results of received power and root mean square delay spread with the corresponding measurements. By removing the impact of directional antennas from the transmitter and receiver, a path loss model as well as small-scale fading properties for typical corridors is presented based on the generated samples from the deterministic model. Results show that the standard deviation of path loss variation is related to the Tx height, and placing the Tx closer to the ceiling leads to a smaller fluctuation of path loss.

Sign in / Sign up

Export Citation Format

Share Document