scholarly journals OBTAINING CONDITIONS FOR TECHNOLOGY NEUTRALITY OF COMMUNICATION SYSTEMS WITH MINIMUM COUPLING LOSS METHOD

2021 ◽  
pp. 27-39
Author(s):  
Volodymyr Korsun ◽  
Anatolii Tychynskyi
Keyword(s):  
Communication Systems ◽  
Power Analysis ◽  
Frequency Characteristics ◽  
Base Stations ◽  
Practical Implementation ◽  
Coupling Loss ◽  
Guard Band ◽  
Loss Method ◽  
Adjacent Channels ◽  
General Method

Background. Technology neutrality is widely used in frequency bands, where communication systems are evolving, but there are strict restrictions on the parameters and deployment of base stations of different technologies using adjacent channels. Ways to mitigate this effect have not been sufficiently studied and require further analysis and development. Objective. The purpose of this article is to investigate the methodology for obtaining technical conditions of technological neutrality with minimum coupling loss method to determine the value of additional filtering requirements and present the results of practical implementation of this technique. Methods. The method of detailed power analysis of frequency characteristics of filters for base stations’ transmitter and receiver is applied. Results. The article presents the results of obtaining minimal guard band and additional filtering requirements in the adjacent channels of transmitter and receiver belonging to different technologies. Examples of practical implementation of the minimum guard band and frequency characteristics of additional filters are given. Conclusions. The general method of determining the technical conditions for ensuring technology neutrality is presented and the value of the minimal required guard band between the adjacent transmitter and receiver channels is obtained.

scholarly journals Interference Cancellation Based Spectrum Sharing for Massive MIMO Communication Systems

Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3584
Author(s):  
Milembolo Miantezila Junior ◽  
Bin Guo ◽  
Chenjie Zhang ◽  
Xuemei Bai
Keyword(s):  
Interference Cancellation ◽  
Communication Systems ◽  
Spectrum Sharing ◽  
Null Space ◽  
Base Station ◽  
Base Stations ◽  
Small Cells ◽  
Data Traffic ◽  
New Approach ◽  
Lte Advanced

Cellular network operators are predicting an increase in space of more than 200 percent to carry the move and tremendous increase of total users in data traffic. The growing of investments in infrastructure such as a large number of small cells, particularly the technologies such as LTE-Advanced and 6G Technology, can assist in mitigating this challenge moderately. In this paper, we suggest a projection study in spectrum sharing of radar multi-input and multi-output, and mobile LTE multi-input multi-output communication systems near m base stations (BS). The radar multi-input multi-output and mobile LTE communication systems split different interference channels. The new approach based on radar projection signal detection has been proposed for free interference disturbance channel with radar multi-input multi-output and mobile LTE multi-input multi-output by using a new proposed interference cancellation algorithm. We chose the channel of interference with the best free channel, and the detected signal of radar was projected to null space. The goal is to remove all interferences from the radar multi-input multi-output and to cancel any disturbance sources from a chosen mobile Communication Base Station. The experimental results showed that the new approach performs very well and can optimize Spectrum Access.

scholarly journals Time–Frequency-Analysis-Based Blind Modulation Classification for Multiple-Antenna Systems

Sensors ◽  
2021 ◽  
Vol 21 (1) ◽  
pp. 231
Author(s):  
Weiheng Jiang ◽  
Xiaogang Wu ◽  
Yimou Wang ◽  
Bolin Chen ◽  
Wenjiang Feng ◽  
...  
Keyword(s):  
Frequency Analysis ◽  
Classification Accuracy ◽  
Communication Systems ◽  
Mimo Systems ◽  
Decision Fusion ◽  
Frequency Characteristics ◽  
Modulation Classification ◽  
Time Frequency Analysis ◽  
Time Frequency ◽  
Average Classification Accuracy

Blind modulation classification is an important step in implementing cognitive radio networks. The multiple-input multiple-output (MIMO) technique is widely used in military and civil communication systems. Due to the lack of prior information about channel parameters and the overlapping of signals in MIMO systems, the traditional likelihood-based and feature-based approaches cannot be applied in these scenarios directly. Hence, in this paper, to resolve the problem of blind modulation classification in MIMO systems, the time–frequency analysis method based on the windowed short-time Fourier transform was used to analyze the time–frequency characteristics of time-domain modulated signals. Then, the extracted time–frequency characteristics are converted into red–green–blue (RGB) spectrogram images, and the convolutional neural network based on transfer learning was applied to classify the modulation types according to the RGB spectrogram images. Finally, a decision fusion module was used to fuse the classification results of all the receiving antennas. Through simulations, we analyzed the classification performance at different signal-to-noise ratios (SNRs); the results indicate that, for the single-input single-output (SISO) network, our proposed scheme can achieve 92.37% and 99.12% average classification accuracy at SNRs of −4 and 10 dB, respectively. For the MIMO network, our scheme achieves 80.42% and 87.92% average classification accuracy at −4 and 10 dB, respectively. The proposed method greatly improves the accuracy of modulation classification in MIMO networks.

scholarly journals Non-Line-of-Sight Error Mitigation in Wireless Communication Systems

2011 ◽  
Vol 1 ◽  
pp. 173-177
Author(s):  
Szu Lin Su ◽  
Yi Wen Su ◽  
Ho Nien Shou ◽  
Chien Sheng Chen
Keyword(s):  
Communication Systems ◽  
Hybrid Methods ◽  
Mobile Station ◽  
Base Stations ◽  
Superior Performance ◽  
Line Of Sight ◽  
Time Of Arrival ◽  
Angle Of Arrival ◽  
Error Statistics ◽  
Non Line Of Sight

When there is non-line-of-sight (NLOS) path between the mobile station (MS) and base stations (BSs), it is possible to integrate many kinds of measurements to achieve more accurate measurements of the MS location. This paper proposed hybrid methods that utilize time of arrival (TOA) at five BSs and angle of arrival (AOA) information at the serving BS to determine the MS location in NLOS environments. The methods mitigate the NLOS effect simply by the weighted sum of the intersections between five TOA circles and the AOA line without requiring priori knowledge of NLOS error statistics. Simulation results show that the proposed methods always give superior performance than Taylor series algorithm (TSA) and the hybrid lines of position algorithm (HLOP).

scholarly journals Energy Optimization of a Laser-Powered Hovering-UAV Relay in Optical Wireless Backhaul

2021 ◽  
Author(s):  
Muhammad Salman Bashir ◽  
Mohamed-Slim Alouini
Keyword(s):  
Quality Of Service ◽  
Communication Systems ◽  
Low Cost ◽  
Base Stations ◽  
Achievable Rate ◽  
Optical Wireless ◽  
Free Space Optical ◽  
Decode And Forward ◽  
Wireless Backhaul

<div>Due to their flexibility and low cost deployment, unmanned aerial vehicles (UAV) will most likely act as base stations and backhaul relays in the next generation of wireless communication systems. However, these UAVs---in the untethered mode---can only operate for a finite time due to limited energy they carry in their batteries. In free-space optical communications, one solution is to transport both the data and the energy from the source to the UAV through the laser beam---a concept known as <i>simultaneous lightwave information and power transfer</i> (SLIPT). In this study, we have analyzed the SLIPT scheme for laser-powered decode-and-forward UAV relays in an optical wireless backhaul. The major goal of this study is to optimally allocate the received beam energy between the decoding circuit, the transmitting circuit and the rotor block of the relay in order to maximize a quality-of-service metric such as maximum achievable rate, outage or error probabilities. As expected, we note that the optimal power allocation depends heavily on the source-relay and relay-destination channel conditions. In the final part of this study, we have maximized the operational time of the UAV relay given that the maximum achievable rate stays above a certain threshold in order to meet a minimum quality-of-service requirement.</div>

scholarly journals Implementation of the asynchronous signals reception method with the direct sequence spread spectrum

2020 ◽  
Vol 30 (2) ◽  
pp. 49-54
Author(s):  
I. V. Egorov ◽  
D. V. Gaivoronskii
Keyword(s):  
Spread Spectrum ◽  
Communication Systems ◽  
Block Diagram ◽  
Random Sequence ◽  
Direct Sequence Spread Spectrum ◽  
Practical Implementation ◽  
Direct Sequence ◽  
Radio Communication ◽  
Radio Stations ◽  
Synchronization Mechanisms

The physical and logical organization of most existing communication systems provides for additional options (transmission of known preambles, the presence of an additional synchronization channel) that simplify synchronization. At the same time, in the practical implementation of radio communication systems, it is necessary to solve the problems of developing additional synchronization mechanisms that can reduce the time it takes to synchronize to reduce energy consumption and increase channel capacity. Thus, the existing problem of the asynchrony of the generators of physically remote radio stations is relevant. One of the possible solutions is asynchronous signal reception with the direct sequence spread spectrum. It allows converting the original binary signal into a pseudo-random sequence for modulating the carrier. The current article is devoted to the characterization of this method and has the following items presented: the transmitter and receiver block diagram, sufficient to explain the proposed method; methods for compensating for effects arising from the asynchrony of the transmitter and receiver generators. Since synchronization is generated according to the correlation peaks that correspond to the data bits, it is possible to set the frequency of the chips on the transmitter to jitter artificially and supplement the pseudo-random sequence with several random chips, which complicates the unauthorized detection of the transmitted signal.

scholarly journals Application of communication systems via the ultraviolet channel in FANET networks

2020 ◽  
Vol 309 ◽  
pp. 01013
Author(s):  
Gleb S. Vasilyev ◽  
Oleg R. Kuzichkin ◽  
Dmitriy I. Surzhik ◽  
vetlana M. Kharchuk
Keyword(s):  
Optical Communication ◽  
Communication Systems ◽  
Network Performance ◽  
Ad Hoc ◽  
General Scheme ◽  
Line Of Sight ◽  
Practical Implementation ◽  
Optical Transmitter ◽  
Hoc Networks ◽  
Uv C

The possibility of providing communication in difficult conditions on the basis of Flying Ad Hoc Networks (FANET) requires the use of non-electronic means of communication. It is proposed to use optical communication in the UV-C range in the absence of line-of-sight between the nodes of the FANET network. The general scheme of the optical transmitter and receiver of UV-C range is considered and the review of the components required for its implementation, taking into account the application possibility in highly mobile small-sized UAVs, is carried out. As a result of the analysis of FANET networks with UV-C channel, physical and channel level parameters critical for network performance are revealed. Methods of adaptive change of these parameters in the practical implementation of the UV-C communication system in FANET networks are proposed.

scholarly journals Wideband and UWB Antennas for Wireless Applications: A Comprehensive Review

2017 ◽  
Vol 2017 ◽  
pp. 1-45 ◽  
Author(s):  
Renato Cicchetti ◽  
Emanuela Miozzi ◽  
Orlandino Testa
Keyword(s):  
Communication Systems ◽  
Base Stations ◽  
Portable Devices ◽  
Comprehensive Review ◽  
Dielectric Resonator Antennas ◽  
Analysis And Design ◽  
Wireless Applications ◽  
Uwb Antennas ◽  
Time Domain Response ◽  
Manufacturing Technologies

A comprehensive review concerning the geometry, the manufacturing technologies, the materials, and the numerical techniques, adopted for the analysis and design of wideband and ultrawideband (UWB) antennas for wireless applications, is presented. Planar, printed, dielectric, and wearable antennas, achievable on laminate (rigid and flexible), and textile dielectric substrates are taken into account. The performances of small, low-profile, and dielectric resonator antennas are illustrated paying particular attention to the application areas concerning portable devices (mobile phones, tablets, glasses, laptops, wearable computers, etc.) and radio base stations. This information provides a guidance to the selection of the different antenna geometries in terms of bandwidth, gain, field polarization, time-domain response, dimensions, and materials useful for their realization and integration in modern communication systems.

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