Directional propagation channel estimation and analysis in urban environment with panoramic photography

International audienceThis article aims to provide readers with a physical understanding of the propagation channel that is complementary to mathematical channel modeling. It presents an analysis of the directional propagation channel based on radiophotos. Radiophotos are graphical objects where directions of arrival are superimposed on three-dimensional (3D) panoramic photographs.The interaction between electro magnetic waves and the environment is immediately identified with these representations. This paper focuses on the direction of arrival at mobile in an urban macrocell environment. The first radiophoto collection illustrates the major propagation phenomena such as reflection, diffraction, or street canyoning. The second collection illustrates typical propagation channel profiles that are classified according to delay, azimuth, and elevation spread values. The paper also describes an original panorama-based method for estimating noise level in the azimuth–elevation domain

Typical MIMO propagation channels in urban macrocells at 2GHz

International audienceA directional wideband measurement campaign was performed in urban macrocells at 2 GHz using a channel sounder and a 8-sensor linear antenna array at the base station. Directions of arrival at the Base Station (BS) were estimated by beamforming using the antenna array. Directions of arrival at the Mobile Station (MS) were estimated by beamforming using parts of the measurement route. Global parameters (delay spread, azimuth spread at BS, maximum factor and street canyon factor) were processed from the Azimuth-Delay Power Profiles (ADPP) at BS and MS. In this paper, we compare the statistics of these four parameters with the statistics of those simulated by the 3GPP-SCM system-level model and the statistics of those reported in the literature. We find an acceptable agreement between our measurements and the SCM model except for the delay spread and the street canyon factor. The azimuth spread at BS mean Value (9.5°) and delay spread mean value (0.250 μs) are also in accordance with values reported in other references. Azimuth spreads are ranged from 7° to 11°, and delay spreads are ranged from 0.1 μs to 1 μs. From a statistical analysis of global parameters, we show that most of the measured propagation Channels can be classified in three main categories: low spatial diversity at MS and BS, high spatial diversity at MS and BS, low spatial diversity at BS and high spatial diversity at MS

Utilisation des photos panoramiques pour la compréhension des phénomènes physiques du canal de propagation

International audienceCet article décrit une méthode du canal de propagation. Les directions d'arrivée sont juxtaposées sur des photos panoramiques 3D. L'ensemble appelé radiophoto permet la corrélation entre la mesure du canal et l'environnement. Les phénomènes physiques tels que la réflexion ou la dffraction sont facilement identifiés

Recherche de bonnes séquences pour l'estimation du canal radiomobile

Une bonne caractérisation du canal est indispensable à la mise au point des futurs systèmes radiomobiles à hauts débits. L'article présente une méthode de synthèse d'un signal de mesure optimal, ou bonne séquence, pour l'estimation de la réponse impulsionnelle du canal radiomobile. Les contraintes liées à la transmission (signal à enveloppe constante pour profiter de toute la puissance des émetteurs, occupation spectrale limitée) et les contraintes liées à la réalisation du matériel (quantification, bande passante des convertisseurs, etc.) ont été prises en compte. Les séquences obtenues permettent la réalisation d'un matériel aux performances accrues

On the Frequency Dependency of Radio Channel's Delay Spread: Analyses and Findings From mmMAGIC Multi-frequency Channel Sounding

This paper analyzes the frequency dependency of the radio propagation channel's root mean square (rms) delay spread (DS), based on the multi-frequency measurement campaigns in the mmMAGIC project. The campaigns cover indoor, outdoor, and outdoor-to-indoor (O2I) scenarios and a wide frequency range from 2 to 86 GHz. Several requirements have been identified that define the parameters which need to be aligned in order to make a reasonable comparison among the different channel sounders employed for this study. A new modelling approach enabling the evaluation of the statistical significance of the model parameters from different measurements and the establishment of a unified model is proposed. After careful analysis, the conclusion is that any frequency trend of the DS is small considering its confidence intervals. There is statistically significant difference from the 3GPP New Radio (NR) model TR 38.901, except for the O2I scenario.Comment: This paper has been accepted to the 2018 12th European Conference on Antennas and Propagation (EuCAP), London, UK, April 201

Characterization, modeling and simulation of the MIMO propagation channel

International audienceThis article deals with several aspects relative to the MIMO propagation channel. Based on simulations and/or measurements, different approaches are used to model the propagation channel. These models are useful for the MIMO system design. Several studies are performed in order to realize realistic simulation of MIMO channel. Different measurement techniques are used in characterizing the propagation channel in various environments. Measurement campaigns made in different situations have been analyzed to obtain the relevant statistical parameters of the channel. Simulation of MIMO channel is then presented. Measurement and simulation results provide an evaluation of the capacity of MIMO channel. Obtained results show feasibility in the integration of MIMO techniques in practical wireless communication systems.Cet article traite de plusieurs aspects relatifs au canal de propagation MIMO. Différentes approches, basées sur des simulations et des mesures, utilisées pour modéliser le canal sont d’abord présentées. Ensuite, les différentes techniques de mesure utilisées dans le but de caractériser le canal de propagation dans divers milieux sont décrites. Des campagnes de mesures effectuées dans différents environnements sont analysées pour obtenir les paramètres statistiques du canal. Quelques problématiques liées à la simulation du canal MIMO sont évoquées notamment en lien avec une simulation réaliste dans des milieux complexes. Les résultats obtenus, en simulation comme en mesure, permettent une évaluation de la capacité du canal MIMO. Ces résultats permettent de discuter de l’intégration des techniques MIMO dans des systèmes de communication sans fil

Towards versatile access networks (Chapter 3)

Compared to its previous generations, the 5th generation (5G) cellular network features an additional type of densification, i.e., a large number of active antennas per access point (AP) can be deployed. This technique is known as massive multipleinput multiple-output (mMIMO) [1]. Meanwhile, multiple-input multiple-output (MIMO) evolution, e.g., in channel state information (CSI) enhancement, and also on the study of a larger number of orthogonal demodulation reference signal (DMRS) ports for MU-MIMO, was one of the Release 18 of 3rd generation partnership project (3GPP Rel-18) work item. This release (3GPP Rel-18) package approval, in the fourth quarter of 2021, marked the start of the 5G Advanced evolution in 3GPP. The other items in 3GPP Rel-18 are to study and add functionality in the areas of network energy savings, coverage, mobility support, multicast broadcast services, and positionin

A Versatile Propagation Channel Simulator for MIMO Link Level Simulation

<p/> <p>This paper presents a propagation channel simulator for polarized bidirectional wideband propagation channels. The generic channel model implemented in the simulator is a set of rays described by geometrical and propagation features such as the delay, 3D direction at the base station and mobile station and the polarization matrix. Thus, most of the wideband channel models including tapped delay line models, tap directional models, scatterer or geometrical models, ray-tracing or ray-launching results can be simulated. The simulator is composed of two major parts: firstly the channel complex impulse responses (CIR) generation and secondly the channel filtering. CIRs (or CIR matrices for MIMO configurations) are processed by specifying a propagation model, an antenna array configuration, a mobile direction, and a spatial sampling factor. For each sensor, independent arbitrary 3D vectorial antenna patterns can be defined. The channel filtering is based on the overlap-and-add method. The time-efficiency and parameterization of this method are discussed with realistic simulation setups. The global processing time for the CIR generation and the channel filtering is also evaluated for realistic configuration. A simulation example based on a bidirectional wideband channel model in urban environments illustrates the usefulness of the simulator.</p

Fading and shadowing analysis of mobile satellite propagation channel at 1.5 and 2.2GHz using a helicopter

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