scholarly journals In-Orbit Measurements and Analysis of Radio Interference in the UHF Amateur Radio Band from the LUME-1 Satellite

2021 ◽  
Vol 13 (16) ◽  
pp. 3252
Author(s):  
Gara Quintana-Diaz ◽  
Torbjörn Ekman ◽  
José Miguel Lago Agra ◽  
Diego Hurtado de Mendoza ◽  
Alberto González Muíño ◽  
...  
Keyword(s):  
Coefficient Of Variation ◽  
Communication System ◽  
Software Defined Radio ◽  
Average Power ◽  
The Arctic ◽  
Time Variability ◽  
Radio Interference ◽  
Temporal Behaviour ◽  
Amateur Radio ◽  
Radio Band

Radio interference in the uplink makes communication to satellites in the UHF amateur radio band (430–440 MHz) challenging for any satellite application. Interference measurements and characterisation can improve the robustness and reliability of the communication system design. Most published results focus on average power spectrum measurements and heatmaps. We apply a low complexity estimator on an SDR (Software-Defined Radio) to study the interference’s dispersion and temporal variation on-board a small satellite as an alternative. Measuring the Local Mean Envelope (LME) variability with different averaging window lengths enables the estimation of time variability of the interference. The coefficient of variation for the LME indicates how much the signals vary in time and the spread in magnitudes. In this article, theoretical analysis, simulations, and laboratory results were used to validate this measurement method. In-orbit measurements were performed on-board the LUME-1 satellite. Band-limited interference with pulsed temporal behaviour and a high coefficient of variation was detected over North America, Europe, and the Arctic, where space-tracking radars are located. Wide-band pulsed interference with high time variability was also detected over Europe. These measurements show why operators that use a communication system designed for Additive White Gaussian Noise (AWGN) at power levels obtained from heatmaps struggle to command their satellites.

scholarly journals Detection of radio interference in the UHF amateur radio band with the Serpens satellite

2021 ◽  
Author(s):  
Gara Quintana-Diaz ◽  
Diego Nodar-López ◽  
Alberto González Muíño ◽  
Fernando Aguado Agelet ◽  
Chantal Cappelletti ◽  
...  
Keyword(s):  
Radio Interference ◽  
Amateur Radio ◽  
Radio Band

Universal Software Radio Peripheral/GNU Radio-Based Implementation of a Software-Defined Radio Communication System

2019 ◽  
pp. 227-240
Author(s):  
Ehsan Sheybani
Keyword(s):  
Communication System ◽  
Software Defined Radio ◽  
Software Radio ◽  
Block Code ◽  
Radio Station ◽  
Frequency Change ◽  
Gnu Radio ◽  
Radio Communication ◽  
Space Communications ◽  
Radio Communication System

Challenges involved in space communications across wireless channels call for new approaches to radio systems. Due to the growing need for frequency change in modern wireless systems, an adaptive radio system has the highest demand. Software-defined radios (SDR) offer this type of adaptivity as well as compatibility with other standard platforms such as USRP/GNU radio. Despite limitations of this approach due to hardware components, viable modeling and simulation as well as deployable systems are possible using this platform. This chapter presents a detailed implementation procedure for a USRP/GNU radio-based SDR communication system that can be used for practical experiments as well as an academic lab in this field. In this experiment the USRP has been configured to receive signal from a local radio station using the BasicRX model daughterboard. The programmable USRP executes Python block code implemented in the GNU Radio Companion (GRC) on Ubuntu OS.

Secure Baseband Techniques for Generic Transceiver Architecture for Software-Defined Radio

2021 ◽  
pp. 1961-1983
Author(s):  
Nikhil Kumar Marriwala ◽  
Om Prakash Sahu ◽  
Anil Vohra
Keyword(s):  
Communication System ◽  
Software Defined Radio ◽  
Main Part ◽  
Software Radio ◽  
Reliable Communication ◽  
Main Interest ◽  
The Future ◽  
Forward Error ◽  
Programmable Hardware

Software Defined Radio (SDR) systems are the ones which can adapt to the future-proof solution and it covers both existing and emerging standards. An SDR has to possess elements of reconfigurability, intelligence and software programmable hardware. The main interest in any communication group is the sure sending of signals of info from a transmitter to a receiver. The signals are transmitted via a guide who corrupts the signal. To ensure reliable communication forward error-correcting (FEC) codes are the main part of a communication system. This chapter will discuss an SDR system built using LabVIEW for a Generic Transceiver. This chapter has covered emerging software radio standards and the technologies being used to specify and support them.

scholarly journals Visible Light Communication System Based on Software Defined Radio: Performance Study of Intelligent Transportation and Indoor Applications

Electronics ◽  
2019 ◽  
Vol 8 (4) ◽  
pp. 433 ◽  
Author(s):  
Radek Martinek ◽  
Lukas Danys ◽  
Rene Jaros
Keyword(s):  
Visible Light ◽  
Communication System ◽  
Software Defined Radio ◽  
Density Ratio ◽  
Visible Light Communication ◽  
Noise Power ◽  
Error Vector Magnitude ◽  
Performance Study ◽  
Variable Nature ◽  
Ceiling Light

In this paper, our first attempt at visible light communication system, based on software defined radio (SDR) and implemented in LabVIEW is introduced. This paper mainly focuses on two most commonly used types of LED lights, ceiling lights and LED car lamps/tail-lights. The primary focus of this study is to determine the basic parameters of real implementation of visible light communication (VLC) system, such as transmit speed, communication errors (bit-error ratio, error vector magnitude, energy per bit to noise power spectral density ratio) and highest reachable distance. This work focuses on testing various multistate quadrature amplitude modulation (M-QAM). We have used Skoda Octavia III tail-light and Phillips indoor ceiling light as transmitters and SI PIN Thorlabs photodetector as receiver. Testing method for each light was different. When testing ceiling light, we have focused on reachable distance for each M-QAM variant. On the other side, Octavia tail-light was tested in variable nature conditions (such as thermal turbulence, rain, fog) simulated in special testing box. This work will present our solution, measured parameters and possible weak spots, which will be adjusted in the future.

scholarly journals Power Allocation for Reducing PAPR of Artificial-Noise-Aided Secure Communication System

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Tao Hong ◽  
Geng-xin Zhang
Keyword(s):  
Power Allocation ◽  
Nonconvex Optimization ◽  
Communication System ◽  
Secure Communication ◽  
Optimization Problem ◽  
Optimization Problems ◽  
Average Power ◽  
Finite Alphabet ◽  
Artificial Noise ◽  
Communication Signals

The research of improving the secrecy capacity (SC) of wireless communication system using artificial noise (AN) is one of the classic models in the field of physical layer security communication. In this paper, we consider the peak-to-average power ratio (PAPR) problem in this AN-aided model. A power allocation algorithm for AN subspaces is proposed to solve the nonconvex optimization problem of PAPR. This algorithm utilizes a series of convex optimization problems to relax the nonconvex optimization problem in a convex way based on fractional programming, difference of convex (DC) functions programming, and nonconvex quadratic equality constraint relaxation. Furthermore, we also derive the SC of the proposed signal under the condition of the AN-aided model with a finite alphabet and the nonlinear high-power amplifiers (HPAs). Simulation results show that the proposed algorithm reduces the PAPR value of transmit signal to improve the efficiency of HPA compared with benchmark AN-aided secure communication signals in the multiple-input single-output (MISO) model.

PA Linearization by Digital Predistortion and Peak-to-Average Power Ratio Reduction in Software Defined Radios

2019 ◽  
Vol 29 (09) ◽  
pp. 2050147
Author(s):  
Borisav Jovanović ◽  
Srdan Milenković
Keyword(s):  
Software Defined Radio ◽  
Average Power ◽  
Power Ratio ◽  
Digital Predistortion ◽  
Error Vector Magnitude ◽  
Power Efficient ◽  
Linearization Methods ◽  
Telecommunication Infrastructure ◽  
Power Ratio Reduction ◽  
Wireless Infrastructure

Digital predistortion (DPD), based on complex-valued memory polynomials (MP), is established as an efficient method for power amplifier (PA) linearization. The DPD facilitates compliance of the telecommunication infrastructure to strict standard specifications (transmit spectrum mask (TSM), error vector magnitude (EVM), bit error rate (BER), [Formula: see text]) by making PA more linear, while at the same time reduces the running cost of the wireless infrastructure (at both Base Transceiver Station (BTS) and User Equipment (UE) sides) by making PA more power efficient. Even when DPD is utilized, signals with high peak-to-average power ratio (PAPR) produce out-of-band PA spectrum emission due to intermodulation products affecting all above-mentioned critical standard specified parameters. The novelty proposed in this paper is as follows. PA is restricted to operate within “reasonably above” PA linear region using PAPR reduction technique. The residual nonlinearity is taken care of by DPD. The combination of DPD and PAPR PA linearization methods is implemented on software-defined radio board. The necessary steps for efficient PA linearization are presented, compensating both out-of-band and in-band signal distortions. We achieved EVM = 2.0%, ACPR [Formula: see text]50[Formula: see text]dBc, at 10[Formula: see text]W LTE modulated PA output, antenna point and PA output power of 39.5[Formula: see text]dBm.

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