Simulations and measurements of the radio channel propagation parameters in urban and industrial environments for emergency localization

Author(s):  
Eran Greenberg ◽  
Shachar Greenberg
Sensors ◽  
2021 ◽  
Vol 21 (6) ◽  
pp. 2015
Author(s):  
Ahmed Al-Saman ◽  
Marshed Mohamed ◽  
Michael Cheffena ◽  
Arild Moldsvor

Wireless data traffic has increased significantly due to the rapid growth of smart terminals and evolving real-time technologies. With the dramatic growth of data traffic, the existing cellular networks including Fifth-Generation (5G) networks cannot fully meet the increasingly rising data rate requirements. The Sixth-Generation (6G) mobile network is expected to achieve the high data rate requirements of new transmission technologies and spectrum. This paper presents the radio channel measurements to study the channel characteristics of 6G networks in the 107–109 GHz band in three different industrial environments. The path loss, K-factor, and time dispersion parameters are investigated. Two popular path loss models for indoor environments, the close-in free space reference distance (CI) and floating intercept (FI), are used to examine the path loss. The mean excess delay (MED) and root mean squared delay spread (RMSDS) are used to investigate the time dispersion of the channel. The path loss results show that the CI and FI models fit the measured data well in all industrial settings with a path loss exponent (PLE) of 1.6–2. The results of the K-factor show that the high value in industrial environments at the sub-6 GHz band still holds well in our measured environments at a high frequency band above 100 GHz. For the time dispersion parameters, it is found that most of the received signal energy falls in the early delay bins. This work represents a first step to establish the feasibility of using 6G networks operating above 100 GHz for industrial applications.


Author(s):  
T. D. Borisova ◽  
N. F. Blagoveshchenskaya ◽  
A. S. Kalishin

In this paper we present the results of studies the distinctive features of the decameter radio wave propagation based on the results of experimental measurements of radio wave propagation characteristics by the ionospheric oblique sounding (IOS) method and numerical simulation. An algorithm for numerical modeling the trajectory and energetic characteristics of the decameter radio wave propagation in the framework of geometric optics is described. The agreement between the simulated and experimental radio propagation parameters (for example, the values of the maximum observed frequencies) is demonstrated. It is proposed to use the developed diagnostic model of the HF radio channel for the purposes of forecasting in areas not provided with IOS stations.


Author(s):  
M. B. Sergeev ◽  
V. A. Nenashev ◽  
A. M. Sergeev

Introduction: The problem of noise-free encoding for an open radio channel is of great importance for data transfer. The results presented in this paper are aimed at stimulating scientific interest in new codes and bases derived from quasi-orthogonal matrices, as a basis for the revision of signal processing algorithms.Purpose: Search for new code sequences as combinations of codes formed from the rows of Mersenne and Raghavarao quasi-orthogonal matrices, as well as complex and more efficient Barker — Mersenne — Raghavarao codes.Results: We studied nested code sequences derived from the rows of quasi-orthogonal cyclic matrices of Mersenne, Raghavarao and Hadamard, providing estimates for the characteristics of the autocorrelation function of nested Barker, Mersenne and Raghavarao codes, and their combinations: in particular, the ratio between the main peak and the maximum positive and negative “side lobes”. We have synthesized new codes, including nested ones, formed on the basis of quasi-orthogonal matrices with better characteristics than the known Barker codes and their nested constructions. The results are significant, as this research influences the establishment and development of methods for isolation, detection and processing of useful information. The results of the work have a long aftermath because new original code synthesis methods need to be studied, modified, generalized and expanded for new application fields.Practical relevance: The practical application of the obtained results guarantees an increase in accuracy of location systems, and detection of a useful signal in noisy background. In particular, these results can be used in radar systems with high distance resolution, when detecting physical objects, including hidden ones.


Author(s):  
Teodor Narytnik ◽  
Vladimir Saiko

The technical aspects of the main promising projects in the segments of medium and low-orbit satellite communication systems are considered, as well as the project of the domestic low-orbit information and telecommunications system using the terahertz range, which is based on the use of satellite platforms of the micro- and nanosatellite class and the distribution of functional blocks of complex satellite payloads more high-end on multiple functionally related satellites. The proposed system of low-orbit satellite communications represents the groupings of low-orbit spacecraft (LEO-system) with the architecture of a "distributed satellite", which include the groupings of the root (leading) satellites and satellite repeaters (slaves). Root satellites are interconnected in a ring network by high-speed links between the satellites. The geometric size of the “distributed satellite” is the area around the root satellite with a radius of about 1 km. The combination of beams, which are formed by the repeater satellites, make up the service area of the LEO system. The requirements for the integrated service area of the LEO system (geographical service area) determine the requirements for the number of distributed satellites in the system as a whole. In the proposed system to reduce mutual interference between the grouping of the root (leading) satellites and repeater satellites (slaves) and, accordingly, minimizing distortions of the information signal when implementing inter-satellite communication, this line (radio channel) was created in an unlicensed frequency (e.g., in the terahertz 140 GHz) range. In addition, it additionally allows you to minimize the size of the antennas of such a broadband channel and simplify the operation of these satellite systems.


2019 ◽  
pp. 55-59
Author(s):  
V. V. Zvonarev ◽  
I. A. Karabelnikov ◽  
A. S. Popov

The paper considers the problem of calculation of average probability of error of optimum symbol‑by‑symbol coherent reception of binary opposite phase‑shift keyed signals (BPSK) in the presence of similar synchronous noise. The noise similar to signal of PSK‑2 (BPSK), synchronous on clock periods, matching on frequency, differing in sequence of information characters and, perhaps, on initial phase of the bearing fluctuation is considered, up to mutual coherence of signal and noise. Formulas for calculation of probability of error are derived and results of partial computer type of diagrams of tension are given in some points of the correlation receiver. Optimum reception of discrete signals is carried out by means of the correlation receiver or the coordinated filter configured on signal in lack of noise in the presence of only receiver noises. It is shown that availability of synchronous similar or harmonious coherent noise, aim on structure, leads to decrease in noise stability of radio channel of information transfer. Than the level of noise is higher, that the probability of error is more.


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