Software Defined Radio System Research Articles

A 2–36 GHz CMOS LNA with π-Network-Based wideband interstage matching technique for software-defined radio systems

With the advance in wireless communication, next-generation software-defined radio (SDR) systems require transceivers to operate in both sub-6GHz and millimeter-wave (mmWave) band and support multiple standards. However, bridging sub-6GHz frequencies with millimeter-wave bands exceeding 30 GHz remains a challenge for conventional wideband LNAs. To surmount this, a 2–36 GHz CMOS low-noise amplifier (LNA) designed for SDR systems is introduced in this paper. An innovative wideband input matching network capable of spanning both frequency domains is proposed. The methodology effectively mitigates the impact of vast parasitic capacitances, achieving wideband input matching against Electrostatic Discharge (ESD) and on-chip decoupling capacitor parasitic. In addition, a π-network-based wideband interstage matching technique is adopted to extend bandwidth of gain. A tri-stage prototype of the proposed LNA, designed using a 40-nm CMOS process, is designed to validate our design strategies. The post-simulation outcomes reveal a peak gain of 14 dB with a -3dB bandwidth ranging from 2 to 36 GHz, equating to a fractional bandwidth of 178 %. The Noise Figure (NF) is commendably uniform across the frequency spectrum, stabilizing at 5 dB. Furthermore, the third-order input intercept point (IIP3) is −4.2dBm to -3dBm across the bandwidth. The performance is achieved with a power of 19.4 mW and within a core area of 0.1 mm2.

Optimal demodulation domain for microwave SQUID multiplexers in presence of readout system noise

The Microwave SQUID Multiplexer (μMUX) is the device of choice for the readout of a large number of low-temperature detectors in a wide variety of experiments within the fields of astronomy and particle physics. While it offers large multiplexing factors, the system noise performance is highly dependent on the cold- and warm-readout electronic systems used to read it out, as well as the demodulation domain and parameters chosen. In order to understand the impact of the readout systems in the overall detection system noise performance, first, we extended the available μMUX simulation frameworks, including additive and multiplicative noise sources in the probing tones (i.e., phase and amplitude noise), along with the capability of demodulating the scientific data, either in the resonator’s phase or the scattering amplitude. Then, considering the additive noise as a dominant noise source, the optimum readout parameters to achieve minimum system noise were found for both open-loop and flux-ramp demodulation schemes in the aforementioned domains. Later, we evaluated the system noise sensitivity to multiplicative noise sources under the optimum readout parameters. Finally, as a case study, we evaluated the optimal demodulation domain and the expected system noise level for a typical software-defined radio readout system. This work leads to an improved system performance prediction and noise engineering based on the available readout electronics and the selected demodulation domain.

Full-Scale Readout Electronics for the ECHo Experiment

Recent advances in the development of cryogenic particle detectors such as magnetic microcalorimeters allow the fabrication of sensor arrays with an increasing number of pixels. Since these detectors must be operated at the lowest temperatures, the readout of large detector arrays is still quite challenging. This is especially true for the ECHo experiment, which presently aims to simultaneously run 6,000 two pixel detectors to investigate the electron neutrino mass. For this reason, we developed a readout system based on a microwave SQUID multiplexer (μ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\mu$$\\end{document}MUX) that is operated by a custom software-defined radio (SDR) at room-temperature. The SDR readout electronics consist of three distinct hardware units: a data processing board with a Xilinx ZynqUS+ MPSoC; a converter board that features DACs, ADCs, and a coherent clock distribution network; and a radio frequency front-end board to translate the signals between the baseband and the microwave domains. Here, we describe the characteristics of the full-scale SDR system. First, the generated frequency comb for driving the μ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\mu$$\\end{document}MUX was evaluated. Subsequently, by operating the SDR in direct loopback, the crosstalk of the individual channels after frequency demultiplexing was investigated. Finally, the system was used with a 16-channel μ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\mu$$\\end{document}MUX to evaluate the linearity of the SDR, and the noise contributed to the overall readout setup.

Development of an Affordable FPGA Board for Advancing Software-Defined Radio Research in Auchi Polytechnic

This paper detailed the design and development of an affordable software-defined radio (SDR) system tailored for academic environments at Auchi Polytechnic. The system integrated a moderately fast analog-to-digital converter (ADC), an audio digital-to-analog converter (DAC), and an off-the-shelf field-programmable gate array (FPGA) for digital signal processing. The primary objective was to enhance the teaching of fundamental engineering concepts related to communications. To demonstrate its capabilities, the system included hardware blocks for demodulating amplitude modulation (AM) and frequency modulation (FM) signals. This approach provided a cost-effective solution for advancing SDR research and education. The SDR paradigm, which replaces traditional hardware configurations with flexible software-based solutions, has revolutionized communication receivers. Incorporating SDR into undergraduate curricula has become increasingly valuable, offering students hands-on experience with cutting-edge technologies and skills relevant in both academic and industrial settings. While commercial SDR solutions such as the RTL-SDR dongle offer an accessible introduction to SDR concepts, they often fall short in providing a deep understanding of the underlying principles and design intricacies. To address this educational gap, the developed SDR platform aimed to offer practical experience and delve into the fundamental principles of SDR design, leveraging advancements in digital technologies like FPGAs and ADCs to create a cost-effective, educational SDR system.

Enhanced Spectrum Monitoring Capabilities Based on Software-Defined Radio Systems: Validation of a Real Time Frequency Hopping Signal Detection

Abstract This paper presents the development and validation of a frequency and channel detection application within GNU Radio, with a particular focus on improving the accuracy of Software Defined Radio (SDR) systems in monitoring frequency hopping signals. To test the application, a series of experimental scenarios were implemented using equipment such as a signal generator, a USRP N310 SDR platform, and a VHF wideband antenna. The scenarios included initial laboratory tests involving the generation of frequency hopping continuous wave signals in the 70-91 MHz range, followed by the generation of a 3G cellular standards-specific channel with sweep in the 70-90 MHz range, and a real frequency hopping test using military radio stations. The latter test was performed in the 75-85 MHz range using predefined frequencies (with 2 MHz steps between them) and different hopping rates (100 hops/s, 300 hops/s, 1000 hops/s). The goal of the in-situ tests was to evaluate the detection capabilities under different conditions. The results showed a 100% success rate in identifying and recording hopping frequencies. The results of this study confirm the reliability and effectiveness of the developed GNU Radio application and demonstrate the potential of the system itself for advanced telecommunications and spectrum management tasks in both the commercial and defense sectors.

Design and implementation of SDR (software-defined radio) systems for enhanced signal processing: An experimental study

Design and implementation of SDR (software-defined radio) systems for enhanced signal processing: An experimental study

Реалізація алгоритму пошуку кореляційного інтерферометричного пеленгатора засобами програмної платформи GNU радіо

In the realm of modern radio equipment development, the integration of Software Defined Radio (SDR) systems, encompassing both software and hardware components, has become widespread. SDR systems, particularly, find applications in the creation of direction finders for radio signal sources. The effectiveness of direction finding and the identification of radio radiation sources largely hinge on the technical specifications of the equipment. For contemporary systems aimed at detecting the location of radio radiation sources, direction finders based on a correlation interferometer prove to be highly suitable. These direction finders excel in performing direction finding for a wide array of radio signals, capable of recognizing broadband modulated signals. They can simultaneously process and identify several signals within a single frequency channel, originating either from a singular source of radio signals (coherent) or from multiple sources (incoherent). SDR technology enables programmable reconfiguration of a radio receiver through software. Such receivers boast a broadband radio frequency component with a significant dynamic range, a high-speed Analog-to-Digital Converter (ADC) path, a robust signal processor, and a specialized digital filtering path. SDR receivers are adaptable to signals of various standards and frequencies, depending on the specific tasks at hand. The GNU RADIO software platform stands out as the most flexible open-source software platform for SDR systems. This article delves into the utilization of the GNU RADIO software platform to implement the search algorithm for the direction finder of the correlation interferometer. The Ettus USRP N210 SDR platform was selected for implementing the direction finder using the correlation interferometer algorithm. This study introduces a two-channel software-controlled model of the direction finder, operating according to the correlation interferometer algorithm. The measurement results for the placement angle of radio signal sources yielded an individual absolute error ranging from 2 to 4 degrees, with an average absolute error of about 3 degrees. These results are quite commendable for such mobile two-channel systems. While systems with four or more channels boast higher accuracy, they tend to have lower economic feasibility.

Using Software-Defined radio receivers for determining the coordinates of low-visible aerial objects

The object of this study is the process of determining the coordinates of low-visible aerial objects. The main hypothesis of the research assumed that the signals emitted by airborne systems of airborne objects that are not visible to radar stations have a greater power than the signal reflected from the airborne object. This, in turn, could improve the signal/noise ratio and, accordingly, the accuracy of determining the coordinates of low-visible aerial objects. It is suggested to use Software-Defined Radio receivers to receive such signals emitted by on-board systems of low-visible aerial objects. It was established that the main sources of signals for Software-Defined Radio receivers are signals of command, telemetry, target channels, manual control channels, and satellite navigation. It was established that an additional distinguishing feature when determining the coordinates of low-visible aerial objects is the uniqueness of their spectra and spectrograms. The method of determining the coordinates of low-visible aerial objects when using Software-Defined Radio receivers has been improved, which, unlike the known ones, involves: – the use as signals for Software-Defined Radio of signal receivers of on-board equipment of low-visible aerial objects; – the use of a priori coordinate values of a low-visible aerial object; – conducting additional spectral analysis of signals of on-board systems of low-visible aerial objects. The spectra and spectrograms of signals of on-board systems of aerial objects when using non-directional and directional antennas were experimentally determined. The experimental studies confirm the possibility of using the Software-Defined Radio receiver to receive signals from airborne equipment and improve the signal-to-noise ratio. The accuracy of determining the coordinates of aerial objects when using Software-Defined Radio receivers was evaluated. A decrease in the error of determining plane coordinates by the Software-Defined Radio system of receivers compared to the accuracy of determining coordinates by the P-19 MA radar station was established by an average of 1.88–2.47 times, depending on the distance to the aerial object

Beam Squint in Ultra-Wideband mmWave Systems: RF Lens Array vs. Phase-Shifter-Based Array

In this article, we discuss the potential of radio frequency (RF) lens for ultra-wideband millimeter-wave (mmWave) systems. In terms of the beam squint, we compare the proposed RF lens antenna with the phase shifter-based array for hybrid beamforming. To reduce the complexities for fully digital beamforming, researchers have come up with RF lens-based hybrid beamforming. The use of mmWave systems, however, causes an increase in bandwidth, which gives rise to the beam squint phenomenon. We first find the causative factors for beam squint in the dielectric RF lens antenna. Based on the beamforming gain at each frequency, we verify that, in a specific situation, RF lens can be free of the beam squint effect. We use 3D electromagnetic analysis software to numerically interpret the beam squint of each antenna type. Based on the results, we present the degraded spectral efficiency by system-level simulations with 3D indoor ray tracing. Finally, to verify our analysis, we fabricate an actual RF lens antenna and demonstrate the real performance using a mmWave, NI PXIe, software-defined radio system.

Crypto coding system based on the turbo codes with secret keys

In 1997, the US National Science Foundation recognized the need to unite research communities together to solve mutual problems, overcome challenges, future development and practical applications of cryptography and error correction coding. Recent works in this area are connected with turbo codes, which have a special ability to provide error correction characteristics of the information transmission close to theoretically obtained values. Besides, they are used for television (DVB-RCS, DVB-RCT), wireless local networks (WiMAX), software-defined radio systems, mobile (3G, 4G, Inmarsat) and space (CCSDS) communications etc. In this article is presented the crypto coding system based on turbo codes with secret keys used by interleavers. All calculations are performed during data encoding, which reduces the computational complexity of data pre-encryption. The necessary mathematical apparatus was presented, the security level of the communication system was estimated, a simulation of the error correction characteristics was performed, and multimedia information was processed. The working characteristics of the classical and proposed turbo codecs do not differ statistically. The results can be used in communication systems for various functional purposes.

ALGORITHM FOR APPLICATION OF INFORMATION FOR MANAGEMENT OF USERS SPATIAL DISPOSITION IN THE PROCESS OF AUTOMATED SOFTWARE-DEFINED RADIO COMMUNICATION NETWORK IMPLEMENTED BY ORTHOGONAL FREQUENCY DIVISION AND MULTIPLEXING

A software-defined radio (SDR) system is a radio communication system which uses software for the modulation and demodulation of radio signals. An SDR performs significant amounts of signal processing in a general purpose computer, or a reconfigurable piece of digital electronics. SDR can talk and listen to multiple channels at the same time, also it can be quickly and easily upgraded with enhanced features. In fact, the upgrade could be delivered over-the-air In the long run, SDR is expected to become the dominant technology in radio communications

Software-Defined Radio-Based Contactless Localization for Diverse Human Activity Recognition

This paper presents a study on contactless localization for activity recognition based on radio-frequency sensing. The focus of this study is on the quantitative analysis of the collected data, which is in the form of channel state information (CSI). The proposed method utilizes a software-defined radio (SDR) system in combination with an ensemble learning technique to localize and identify daily living activities such as leaning, sitting, standing and walking. Specifically, SDR device, Universal Software Radio Peripheral (USRP) models X300/X310 are utilized to collect data on the aforementioned activities. The data is collected from an empty space and a participant performing daily living activities in different territories. The acquired data is labelled based on the region, zone and performed activity. The CSI data is subsequently preprocessed and fed into an ensemble-based machine learning algorithm for classification. Furthermore, the stability analysis of the proposed method is performed to evaluate its reliability and robustness. The performance of the algorithm is evaluated using various metrics, including a confusion matrix, accuracy, cross-validation score and training time. The results demonstrate that the proposed ensemble-based approach achieves a high accuracy of up to 90% in activity recognition, highlighting the effectiveness of the proposed method in contactless localization for activity recognition.

Perturbations in the characteristics of ionospheric HF radio waves during the April 11, 2019, earthquake in Japan: Results from oblique sounding

The Harbin Engineering University HF software-defined radio system since 2018 continuously monitors dynamic processes launched in the ionosphere by energetic events in the Sun–interplanetary-medium–magnetosphere–ionosphere–subsystem coupling. The data collected during the submarine magnitude 6.0 earthquake that occurred off the East coast of Honshu, Japan, on April 11, 2019, have been analyzed with the specific objectives of determining the ionospheric response to the earthquake, the distortions of the radio-wave propagation channels, and identifying possible mechanisms for the transport of the disturbances at 845–2,260 km great-circle distances between the epicenter and the propagation path midpoints. Despite the ionospheric responses to powerful earthquakes have been studied since 1964, the problem of deriving global specifications of the disturbances remains pressing. The effects that the ionospheric disturbances from earthquakes have on radar, communications channels, radio navigation, radio astronomy, etc., are a matter of even greater urgency. The multiple path multifrequency radio system for sounding the ionosphere at oblique incidence provides a convenient tool for diagnosing such HF radio-wave propagation problems, acquiring a database containing the complex amplitudes of the signals and used to produce a sequence of Doppler spectra, for the first time, at a rate of 480 spectra per 1 h along 14 radio-wave propagation paths simultaneously with a 7.5-s temporal resolution and 0.02-Hz Doppler resolution over 20-s intervals. Analysis of the Doppler spectra, Doppler shift along the main ray, and signal amplitudes on the day when the earthquake occurred and on quiet time reference days showed that after the earthquake the Doppler spectra exhibit essential broadening, the Doppler shift along the main ray undergoes alternating sign Doppler variations, as well as quasi-sinusoidal variations with 3–5- and 10–20-min periods pertaining to the infrasound and atmospheric gravity wave frequency bands. The relative amplitudes of disturbances in the electron density are estimated to be ∼1% and 2–19% in the fields of infrasound of atmospheric gravity waves, respectively.

Resilient Embedded Systems Designs via on the Fly Generation of Adaptive Degenerate Components Using Machine Learning

Software defined radio (SDR) provides significant advantages over traditional analog radio systems and are becoming increasingly relied on for “mission critical” applications. This along with risk of trojans, single-event upsets and human error creates the necessity for fault tolerant systems. Redundancy has been traditionally used to implement fault tolerance but incurs a substantial area overhead which is undesirable in most applications. Advancements in field-programmable gate array and system on a chip technologies have made implementing machine learning (ML) algorithms within embedded systems feasible. In this paper we explore the use of ML to implement fault tolerance in an SDR. Our approach, which we call adaptive component-level degeneracy (ACD), uses a ML model to learn the functionality of an SDR component. Once trained, the model can detect when the component is compromised and mitigate the issue with its own output. We demonstrate the ability of our model to learn multiple simulated SDR components. We compare the one-dimensional convolutional neural network and bidirectional recurrent neural network architectures at modeling time series components. We also implement ACD within a real-time SDR system using GNU Radio Companion. The results show great potential for the utilization of ML techniques for improving embedded system reliability.

Effects of the super-powerful tropospheric western Pacific phenomenon of September–October 2018 on the ionosphere over China: results from oblique sounding

Abstract. Doppler measurements at oblique propagation paths from the city of Harbin, the People's Republic of China (PRC), to 10 high-frequency (HF) radio broadcast stations in the PRC, Japan, Mongolia, and the Republic of Korea captured the response in the ionosphere to the activity of the super typhoon, Typhoon Kong-rey, from 30 September to 6 October 2018. The Harbin Engineering University coherent software-defined radio system generates the database containing the complex amplitudes of the radio signals that have been acquired along 14 propagation paths since 2018. The complex amplitudes are used for calculating the temporal dependences of the Doppler spectra and signal amplitudes, and the Doppler spectra are used to plot the Doppler shift as a function of time, fD(t), for all rays. The scientific objectives of this study are to reveal the possible perturbations caused by the activity of Typhoon Kong-rey and to estimate the magnitudes of wave parameters of the ionospheric plasma and radio signals. The amplitudes, fDa, of the Doppler shift variations were observed to noticeably increase (factor of ∼2–3) on 1–2 and 5–6 October 2018, while the 20–120 min periods, T, of the Doppler shift variations suggest that the wavelike disturbances in the ionosphere are caused by atmospheric gravity waves. The periods and amplitudes of quasi-sinusoidal variations in the Doppler shift, which have been determined for all propagation paths, may be used to estimate the amplitudes, δNa, of quasi-sinusoidal variations in the electron density. Thus, T≈20 min and fDa≈0.1 Hz yield δNa≈0.4 %, whereas T≈30 min and fDa≈0.2 Hz give δNa≈1.2 %. If T≈60 min and fDa≈0.5 Hz, then δNa≈6 %. The periods T are found to change within the 15–120 min limits, and the Doppler shift amplitudes, fDa, show variability within the 0.05–0.4 Hz limits.

Bandpass Sigma–Delta Modulation: The Path toward RF-to-Digital Conversion in Software-Defined Radio

This paper reviews the state of the art on bandpass ΣΔ modulators (BP-ΣΔMs) intended to digitize radio frequency (RF) signals. A priori, this is the most direct way to implement software-defined radio (SDR) systems since the analog/digital interface is placed closer to the antenna, thus reducing the analog circuitry and doing most of the signal processing in the digital domain. In spite of their higher programmability and scalability, RF BP-ΣΔM analog-to-digital converters (ADCs) require more energy to operate in the GHz range as compared with their low-pass (LP) counterparts. This makes conventional direct conversion receivers (DCRs) the commonplace approach due to their overall smaller energy consumption. This paper surveys some circuits and systems techniques which can make RF ADCs and SDR-based transceivers more efficient and feasible to be embedded in mobile terminals.

A Top-Down Modeling Approach for Networks-on-Chip Components Design: A Switch as Case Study

The design of Networks-on-Chip (NoCs) components implies a wide range of techniques and methods to address the microarchitecture of the packet-forwarding components, where routers and switches are the most complex because they constitute the NoC’s backbone. Due to this complex design space, several works use approaches limiting architectural exploration, focusing only on achieving high-performance levels; therefore, they are inadequate for designing NoC components when particular functionalities are demanded, as in real applications with specific protocols and interfaces. This paper presents a design methodology based on a top-down approach with NoC-oriented abstraction levels to systematically generate a microarchitecture and its hardware description according to system requirements. The design flow transforms a high-level functional model into a microarchitecture model through a refinement process at each abstraction level. This structured approach involves integrating details on how the data is functionally managed within the component according to the system requirements and the processing granularity of each level, allowing testing alternatives in the early stages of the design when necessary. The models of each abstraction level can be described and simulated using the simulator OMNet++. Thus, the obtained microarchitecture model will be directly translated into a Hardware Description Language (HDL). The methodology is tested via the design of a NoC switch for a Software Defined Radio (SDR) system. Performance analysis and implementation results in a field-programmable gate array (FPGA) show that the proposed design is functional and comparable in both area and frequency to other similar state-of-the-art components, and it is also configurable to build star topologies of up to 16 nodes.

Development of a Bench for Analyzing the Radio Station Operation in the APCO P25, DMR and TETRA Communication Standards Based on Broadband Software-Defined Radios and GNU Radio Software Toolkit

The article discusses the development of an instrument complex (bench, stand) for the study of digital radio communication standards: APCO P25, DMR and TETRA, based on software-defined radio systems (SDR) technologies in voice mode. The bench is based on the HackRF One broadband SDR transceiver and the GNU Radio open software toolkit. Along with the SDR transceiver HackRF One, it is proposed to use the SDR TV tuner AstroMeta Digital TV Dongle as an available receiver. The structure of the hardware and software parts of the bench is proposed. The software implementation of listed digital radio communication standards is based on the open libraries of the Osmocom project: the BoadBot OP25 and TETRA Live Monitor libraries. The operating system Linux Debian 10 and the software toolkit GNU Radio 3.7 were used for practical testing of the bench functioning. The practical testing results of the developed bench are presented both when interacting in voice mode with radio stations of the specified radio communication standards, and between the SDR transmitter HackRF One and the SDR TV tuner AstroMeta Digital TV Dongle. For the radio communication standards APCO P25 and DMR, the receiving and transmission modes of the speech signal have been practically tested on the developed bench, and for the radio communication standard TETRA, the modes of scanning the radio broadcast and receiving the speech signal have been tested. As a bench operability confirmation for the listed radio communication standards, the screenshots of programs implementing the specified modes of interaction between the bench hardware components are given. The proposed bench architecture allows to expand the list of supported radio standards. The developed bench can be used: 1) for educational purposes in the study of radio communication standards; 2) in the development and debugging of radio communication systems under development; 3) for control testing during the release of radio systems.

Design and Development of an FPGA Board for Software-Defined Radio Research

This paper describes the design and development of a cost-affordable yet powerful software-defined radio system. The main application environment of the board is in academia where it is used to deliver a multidisciplinary approach in a number of fundamental engineering topics in communications. A moderately fast ADC together with an audio DAC are used for the analog components while an off-the-shelf FPGA is used as the digital processing element. To demonstrate the boards capabilities, hardware blocks to demodulate amplitude modulation and digital modulation were developed.

ОБЗОР ИСТОЧНИКОВ ПОМЕХ В СПУТНИКОВЫХ СИСТЕМАХ СВЯЗИ

The article discusses some sources of interference in satellite communication channels, such as the impact of the ionosphere, space weather and the impact of man-made sources of interference. It is shown that satellite information transmission systems remain relevant and continue to develop, plans and projects for the further development of this type of communication in the Russian Federation are also considered. The relevance of VSAT systems and the scope of their current application are considered, as well as possible ways of using this type of satellite communication are proposed, the main methods of application are monitoring systems and communications in remote places of our planet, as well as the study of space and monitoring the state of satellite repeaters located in outer space. The advantages and disadvantages of building such systems are analyzed, and the idea of leveling the emerging shortcomings by using cognitive radio technologies using the capabilities of software-defined radio systems is proposed.