Software Radio Research Articles

Implementation of FMCW radar at low frequencies

FMCW radar is a low power technique for distance measurement suitable for many applications. At low frequencies, FMCW (Frequency Modulated Continuous Wave) radar can penetrate shadow zones or complex media such as forest. The need for large bandwidth in the measurements may require the use of log periodic antennas. In this study, signal processing and calibration are implemented in Labview, in combination with a USRP (Universal Software Radio Peripheral). A USRP is a form of interface between the RF hardware and the computer. The total bandwidth and the resolution are increased by reusing the bandwidth of the USRP.

Image encryption through RNA approach assisted with neural key sequences

In this paper, an image encryption algorithm is proposed for the first time, which uses coding deoxyribonucleic acid (DNA) sequences to transcript its complementary messenger ribonucleic acid (mRNA) sequence. A binary associative memory neural network (BAM NN) is trained to produce the required transfer ribonucleic acid (tRNA) sequences to bond with the mRNA sequences to assign the correct amino acids. DNA and mRNA sequences, together with tRNA sequences, provide the permutation and diffusion operations for the pixels in colour digital imaging and communications in medicine images. Then, keys, which are determined by the generated amino acids, are used to encrypt the diffused cipher pixels further. Also key sharing has been carried out using Universal Software Radio Peripheral (USRP), cloud infrastructure and One Time Password (OTP) generation mechanisms.The different sequence formation can also identify any alterations made by the intruder in the amino acid, which results in the wrong set of key generation. Various decryption quality analyses, statistical and differential attack analyses (namely mean square error, unified average changing intensity, peak signal-to-noise ratio, number of pixel changing rate, entropy, mean absolute error, key sensitivity, cropping attacks, and chosen-plaintext attacks), and correlation tests were carried out to confirm the robustness of the proposed algorithm.

Distance estimation in OFDM inter-satellite links

One of the practical solutions for space deployment of large-scale scientific instruments is satellite formation flying. In this type of space mission, several smaller satellites have the ability to interact and cooperate with each other via inter-satellite links (ISL) for tasks commonly performed by a larger and more complex satellite. Formation flying missions require accurate knowledge of the satellite positioning with regard to orientation and distance. This paper proposes a distance estimation method applicable in an Orthogonal Frequency-Division Multiplexing (OFDM) ISL. In the proposed technique, called enhanced wide-lane (EWL), the distance is estimated using an OFDM training symbol, and the measurement is based on the correlation between the received symbol and a stored replica. More precisely, a coarse estimation is obtained by detecting the correlation maximum, then it is refined by measuring the correlation phase. The theoretical considerations regarding the precision of the estimation and the influence of frequency offset and multipath propagation are validated using MATLAB simulations and an experimental testbed built with Universal Software Radio Peripheral (USRP) platforms. The results show that the precision of EWL is of sub-mm level in the absence of frequency offset and multipath propagation.

Research on Application of Digital Signal Processing Technology in Communication

With the continuous development of modern information technology and the continuous improvement of people's living standards, electronic information technology has been widely used in people's lives. People's lives are inseparable from it. With its continuous development, its application range is getting wider and wider. This article first gives a brief overview of digital signal processing technology, analyzes the advantages and disadvantages of digital signal processing technology in the communication field, and the specific applications of speech compression coding and software radio in communication are analyzed in order to better promote the application of digital signal processing technology in the communication field.

On the Performance of QPSK Modulation Over Downlink NOMA: From Error Probability Derivation to SDR-Based Validation

In this paper, we study the performance of QPSK modulation in the context of multi-user downlink NOMA with a successive interference canceller (SIC) at the receiver side. The first objective is to evaluate the benefit of such a technique in terms of error probability, regardless of the number of involved users. Analytical derivations on its closed-form have been verified by both simulation and experimental validation. The article uses numerical simulations not only to corroborate the tightness of our theoretical expressions, but also to analyze the problem of power allocation in the two and three users cases. Finally, this paper provides an interplay between NOMA and software radio by building an experimental validation testbed.

Field Trial of Cloud-Connected Wireless Completion System

This article, written by JPT Technology Editor Judy Feder, contains highlights of paper SPE 192940, “Development and Field Trial of the World’s First Cloud-Connected Wireless Intelligent Completion System,” by Annabel Green, SPE, and Paul Lynch, SPE, Tendeka, and Bjarne Bugten, Equinor, prepared for the 2018 Abu Dhabi International Petroleum Exhibition and Conference, 12–14 November. The effectiveness of intelligent completions for production optimization and improvement of reservoir management is well established, yet the use of the technology remains limited to high-value, single-bore wells. The cost and complexity of these solutions, coupled with limitations in well types, interval quantity, and system-interface quality, have prevented broader application. This paper describes the development and field trials of a cloud-connected, wireless intelligent completion system that enables long-term monitoring and interval control to enhance production management by connecting the user wirelessly from the desktop to downhole inflow-control valves (ICVs). Introduction One reason for the high expense of intelligent completion technology is the need for a wire or tubes to control and power downhole equipment such as sliding sleeves. An intelligent completion that communicates wirelessly within the wellbore provides dual benefits in completion operations and production management, and eliminates the requirement for control lines. The all-electric technology also provides greater scope for digital well management and integration with surface systems (Fig. 1). A slimline ICV has been developed that provides infinitely variable choking capability and multiple integrated sensors. Qualification has been completed to the operator’s existing standard for interval control valves adapted and augmented to reflect the differences between the wireless solution and conventional technology. Several field installations have been performed with the system, two of which are detailed in the complete paper. In the first of these two, operations were performed with local-only access to surface data. The project demonstrated the ability to communicate effectively but highlighted some mechanical limitations in the tool itself. After design improvements, a second installation was performed, which also included a surface management system with wireless interpretation software and cloud connectivity. The system described in the paper has been proven to provide robust communication using pressure pulses within the flowing wellstream to provide operating instructions to the ICV, and for the ICV to operate as instructed and communicate effectively to the wellhead. Data from the system have been digitally managed and remotely accessed, demonstrating the ability to change tool settings remotely. Integrating a semiduplex pressure-pulse system, which operates in compressive fluid environments to provide direct communication between a downhole device and wellhead, provides a low-energy communication method compatible with extended-service-life completion tools. The system has been demonstrated with ICV technology in both multiphase and gas environments. In field trials, this has been integrated with an intelligent system, effectively deploying what the authors describe as the world’s first cloud-connected wireless intelligent completion. Excessive water production is a challenge for the production system and does not create value. In this wireless system, the valve is a key element to control the inflow into the well. By measuring and controlling the inflow, shutting off water-producing zones and increasing the production of hydrocarbons is possible.

SoftHM: A Software-Based Hierarchical Modulation Design for Wireless System

Hierarchical Modulation (HM) is quite efficient for multimedia broadcast in wireless networks. It exploits the wireless broadcast advantage and allows a transmission to reach different users with various qualities. However, existing HM related schemes are based on specially designed hardware, leading to extra hardware and deployment cost in practice. As a remedy for this, we design and implement a software-based HM scheme, named as SoftHM. By carefully tuning the Physical Layer input of a packet (a sequence of “0” or “1” bits, known as PHY payload), a transmitter simply broadcasts the packet with a single rate (e.g., 54Mbps, the highest rate in 802.11g WLAN), while diverse receivers can decode and extract different amount of information (with different reception rate, e.g., 12Mbps or 54Mbps) from it based on their link qualities. Reverse engineering techniques are adopted so that SoftHM works in a plug-in mode, offering it high potentials for wireless systems without any changes in existing modulation and coding modules. We implement SoftHM based on Universal Software Radio Peripheral (USRP) B210 and Commercial of the Shelf (COTS) Wi-Fi devices. Both rigorous analysis on its performance and comprehensive implementation-based experiments show that compared with the traditional time-sharing approach, to support low-quality users with the same bandwidth, high-quality users in SoftHM achieve 111.1% to 616.7% higher throughput. Likewise, to serve high-quality users with the same bandwidth, low quality users in softHM achieve 176.9% to 390.9% higher throughput.

Towards Interference-aware ZigBee Transmissions in Heterogeneous Wireless Networks

Cross-technology interference (CTI) from diverse wireless networks such as ZigBee, Bluetooth, and Wi-Fi has become a severe problem in the 2.4 GHz Industrial Scientific and Medical (ISM) band. Especially, low power and lossy networks are vulnerable to the signal interferences from other aggressive wireless networks when they perform low power operations to conserve the energy consumption. This paper presents CoSense, which accurately detects ZigBee signals with a reliable signal correlation scheme in the presence of the CTI. The key concept of CoSense is to reduce false wake-ups of low power listening (LPL) by identifying the pre-defined ZigBee signatures. Our scheme is robust in the coexistence environment of diverse wireless technologies since the signal correlation works well in bad wireless channel conditions. It achieves standard compliance and transparency without any hardware and firmware changes. We have implemented CoSense on the Universal Software Radio Peripheral (USRP) platform to verify its feasibility. The experimental exploration reveals that CoSense significantly reduces the false-positive and false-negative rate under typical setting and the additional overhead is negligible. The results show that our scheme saves much energy by up to 63% in dynamic network interference scenarios where low-power ZigBee transmissions are overwhelmed by strong Wi-Fi signal interferences.

A New Selective Mapping Scheme for Visible Light Systems

The huge bandwidth and immunity to electromagnetic interference make Visible Light Communication (VLC) systems as preferred technique for designing the physical layer of 5G applications. Unfortunately, the superimposition of multiple subcarriers in DC-biased Optical Orthogonal Frequency Division Multiplexing (DCO-OFDM) system leads to a high peak to average power ratio (PAPR). The well-accepted nondistorting PAPR reducing schemes like selective mapping (SLM) require an obligatory transmission of side information (SI) reducing the bandwidth efficiency of the system. To address these issues, a simple SI cancellation algorithm using pilots associated with channel estimation is proposed in this work. In short, the DCO-OFDM system is presented with a modified cluster architecture and each cluster is assigned with at least one pilot. Every cluster is restricted to have same phase and this idea provides the pilots to perform joint channel estimation and SI cancellation. The experimental results obtained by using Universal Software Radio Peripheral (USRP) as hardware and LabVIEW as software indicate a significant reduction in PAPR without effecting the real-time channel response.

Testing different Channel Estimation Techniques in Real-Time Software Defined Radio Environment

In modern wireless communication to maximize spectral efficiency and to minimize the bit error rate OFDM (Orthogonal frequency-domain multiplexing) is used. OFDM is used broadly in networks using various protocols, including wireless vehicular environment IEEE 802.11p, IEEE 802.16d/e Wireless Metropolitan Area Networks, Long-Term Evolution 3GPP networks and IEEE 802.11a/g/n Wireless Local Area Networks. The main challenges involved when using OFDM for wireless communications are short channel-coherence bandwidth and the narrow coherence time, and both have a major effect on the reliability and latency of data packet communication. These properties increase the difficulty of channel equalization because the channel may change drastically over the period of a single packet. Spectral Temporal Averaging is an enhanced decision-directed channel equalization technique that improves communication performance (as far as the frame delivery ratio (FDR) and throughput) in typical channel conditions. This paper reports tests of Spectral Temporal Averaging channel equalization in an IEEE 802.11a network, compared with other channel equalization techniques in terms of the FDR in a real-time environment. Herein, a software defined Radio (SDR) platform was used for estimating the channel. This proves that the system can provide over 90% of delivery ratio at 25 db of Signal to Noise Ratio (SNR) for various digital modulation techniques. For this purpose, an experimental setup consisting of software-defined radio, Universal Software Radio Peripheral (USRP) N210 along with wide bandwidth daughter board as hardware and GNU radio is used.

Implementation of Linearly Pulse Shaped Generalised Frequency Division Multiplexing for Visible Light Communication Systems

In this article, a new modulation scheme named Direct Current biased Optical Generalised Frequency Division Multiplexing (DCO-GFDM) for Visible Light Communications (VLC) is explored. The DCO-GFDM enhances spectral efficiency by slicing both grids on the time-frequency plane and uses a circularly rotating filter for pulse shaping. In the Circular Pulse shaped DCO-GFDM (CP-DCO-GFDM), Root Raised Cosine (RRC) pulse is widely employed. This destroys the orthogonality among sub-carriers and degrades the Bit Error Rate (BER) performance. Therefore, in this work, a Linearly Pulse shaped DCO-GFDM (LP-DCO-GFDM) is proposed to retain the orthogonality among the sub-carriers and simultaneously improve BER and Peak-to-Average Power Ratio (PAPR) performance. The performance of CP/LP-DCO-GFDM is studied under double sided clipping distortion that occurs at the Light Emitting Diode (LED). Presented simulation results agree well with the theoretical results. Additionally, we present an experimental validation of the LP-DCO-GFDM on a Universal Software Radio Peripherals (USRP) based VLC test bed. The experimental results, in terms of Error Vector Magnitudes (EVM)s, the received constellations, and the received spectrum in comparison with DCO-OFDM shows improved performance.

Deep Learning for Modulation Recognition: A Survey With a Demonstration

In this paper, we review a variety of deep learning algorithms and models for modulation recognition and classification of wireless communication signals. Specifically, deep learning (DL) has shown overwhelming advantages in computer vision, robotics, and voice recognition. Recently, DL has been proposed to apply to wireless communications for signal detection and classification in order to better learn the active users for electromagnetic spectrum sharing purposes. Therefore, we aim to provide a survey on the most recent techniques which use DL for recognizing and classifying a wireless signal. We focus on the most widely used DL models, emphasize the advantages and limitations, and discuss the challenges as well as future directions. In addition, we also apply a DL algorithm, convolutional neural network (CNN), to demonstrate the feasibility of using CNN to recognize and classify the over-the-air wireless signals using Mathworks DL toolbox with PlutoSDR and Universal Software Radio Peripheral (USRP), respectively.

Reconfigurable Intelligent Surface-Based Wireless Communications: Antenna Design, Prototyping, and Experimental Results

One of the key enablers of future wireless communications is constituted by massive multiple-input multiple-output (MIMO) systems, which can improve the spectral efficiency by orders of magnitude. In existing massive MIMO systems, however, conventional phased arrays are used for beamforming. This method results in excessive power consumption and high hardware costs. Recently, reconfigurable intelligent surface (RIS) has been considered as one of the revolutionary technologies to enable energy-efficient and smart wireless communications, which is a two-dimensional structure with a large number of passive elements. In this paper, we develop a new type of high-gain yet low-cost RIS that bears 256 elements. The proposed RIS combines the functions of phase shift and radiation together on an electromagnetic surface, where positive intrinsic-negative (PIN) diodes are used to realize 2-bit phase shifting for beamforming. This radical design forms the basis for the world's first wireless communication prototype using RIS having 256 two-bit elements. The prototype consists of modular hardware and flexible software that encompass the following: the hosts for parameter setting and data exchange, the universal software radio peripherals (USRPs) for baseband and radio frequency (RF) signal processing, as well as the RIS for signal transmission and reception. Our performance evaluation confirms the feasibility and efficiency of RISs in wireless communications. We show that, at 2.3 GHz, the proposed RIS can achieve a 21.7 dBi antenna gain. At the millimeter wave (mmWave) frequency, that is, 28.5 GHz, it attains a 19.1 dBi antenna gain. Furthermore, it has been shown that the RIS-based wireless communication prototype developed is capable of significantly reducing the power consumption.

Opportunistic use of Spectral Holes in Karachi using Convolutional Neural Networks

Wireless services appearing in the next generation wireless standard i.e. 6G include Internet of Everything (IoE), Holographic communications, smart transportation and smart cities require exponential rise in the bandwidth in addition to other requirements. The current static spectrum allocation policy does not allow any new entrant to exploit already grid-locked Radio Frequency (RF) spectrum. Hence, quest for larger bandwidth can be fulfilled through other technologies. These include exploiting sub-Terahertz band, Visible Light Communication and Cognitive Radio scheme or exploiting of RF bands in opportunistic fashion. Cognitive Radio is one of those engines to exploit the RF spectrum in secondary style. Cognitive Radio can use artificial intelligence driven algorithms to complete the task. Several intelligent algorithms can be used for better forecasting of spectral holes. Convolutional Neural Network (CNN) is a Deep Learning algorithm that can be used to predict the presence of a spectral holes that can be opportunistically exploited for efficient utilization of RF spectrum in secondary fashion. This paper investigates the performance of CNN for metropolitan Karachi city of Pakistan so that the users can be provided with uninterrupted access to the network even under busy hours. Dataset for the proposed setup is collected for 1805 MHz frequency band through NI 2901 Universal Software Radio Peripheral (USRP) devices. The root mean square error (RMSE) for the predicted results using CNN appears to be 81.02 at epoch of 200 and mini-batch loss of 3281.8. Based on the predicted results, it was concluded that CNN can be useful for investigating the possible opportunistic usage of RF spectrum, however, further investigation is required with different datasets.

A Distributed Testbed for 5G Scenarios: An Experimental Study.

This paper demonstrates the use of Universal Software Radio Peripheral (USRP), together with Raspberry Pi3 B+ (RP3) as the brain (or the decision making engine), to develop a distributed wireless network in which nodes can communicate with other nodes independently and make decision autonomously. In other words, each USRP node (i.e., sensor) is embedded with separate processing units (i.e., RP3), which has not been investigated in the literature, so that each node can make independent decisions in a distributed manner. The proposed testbed in this paper is compared with the traditional distributed testbed, which has been widely used in the literature. In the traditional distributed testbed, there is a single processing unit (i.e., a personal computer) that makes decisions in a centralized manner, and each node (i.e., USRP) is connected to the processing unit via a switch. The single processing unit exchanges control messages with nodes via the switch, while the nodes exchange data packets among themselves using a wireless medium in a distributed manner. The main disadvantage of the traditional testbed is that, despite the network being distributed in nature, decisions are made in a centralized manner. Hence, the response delay of the control message exchange is always neglected. The use of such testbed is mainly due to the limited hardware and monetary cost to acquire a separate processing unit for each node. The experiment in our testbed has shown the increase of end-to-end delay and decrease of packet delivery ratio due to software and hardware delays. The observed multihop transmission is performed using device-to-device (D2D) communication, which has been enabled in 5G. Therefore, nodes can either communicate with other nodes via: (a) a direct communication with the base station at the macrocell, which helps to improve network performance; or (b) D2D that improve spectrum efficiency, whereby traffic is offloaded from macrocell to small cells. Our testbed is the first of its kind in this scale, and it uses RP3 as the distributed decision-making engine incorporated into the USRP/GNU radio platform. This work provides an insight to the development of a 5G network.

Representações sociais de amor romântico nas músicas mais tocadas nas rádios brasileiras em 2015

O objetivo deste estudo foi analisar as representações sociais de amor romântico contidas nas letras das músicas em português mais executadas nas rádios brasileiras no ano de 2015. Foram analisadas 100 canções, identificadas a partir do software de monitoramento de rádio AudioMonitor. Para tratamento dos dados, as letras das músicas foram submetidas à análise lexical, procedida por meio do software Alceste, que indicou a existência de quatro classes. Os resultados demonstram que as representações sociais de amor romântico apresentadas nas canções analisadas seguem um roteiro estável, orientado pelas fases do relacionamento romântico (corte, lua de mel, curso descendente, e fim) e se apresentam, frequentemente, como justificadoras da heteronormatividade e de comportamentos sociais.

Development and Calibration of a Low-Cost Radar Testbed Based on the Universal Software Radio Peripheral

For a cognitive radar algorithm to be useful, it must run on radar hardware that is flexible. Typically, this has been viewed as requiring a software-defined radio. With the emergence of cheap, digital transceiver systems, such as the Universal Software Radio Peripheral (USRP) from Ettus, these systems are cheaper than ever to produce. This article reports on the development of a USRP-based radar system. Calibration testing for radar cross section is undertaken. The phase noise is characterized as having a standard deviation of 0.02 radians. Detections of commercial aircraft at ranges up to 5.5 km are demonstrated. An adaptive update interval tracking experiment, using the fully adaptive radar framework for cognitive radar, is reported on. In this experiment, a small unmanned aerial vehicle is detected at ranges of up to 300 m. Using the radar equation with a signal loss proportional to R−4, the interpolated maximum detection range is approximately 600 m.

Designing a Novel PTS Method to Reduce Peak to Average Power Ratio in OFDM

Most of the wireless standards used these days, heavily rely on Orthogonal Frequency Division Multiplexing (OFDM). Peak to Average Power Ratio (PAPR) is one of the known key acknowledged confines of OFDM. Reduced PAPR at OFDM transmitter helps power amplifier to operate in stable mode and reduction in complexity of digital to analog converter (DAC). Several PAPR reduction techniques have been evolved from different principles such as signal scrambling techniques, such as Partial Transmit Sequence (PTS), signal distortion techniques such as Clipping, etc. Reducing PAPR degrades bit error rate (BER) or computational complexity. PTS is one of the best methods of PAPR reduction. There is large scope of betterment of PTS to get a best PAPR reduction technique. In this paper we have concentrated on PTS scheme by exploring PTS and its variants evolved over a period of time. We proposed a novel PTS with best performance balancing PAPR and BER performance. Design and development of scheme is done using a graphical programming environment LabVIEW (Laboratory Virtual Instrumentation Engineering Workbench) and real time environment validation is done with software defined radio – NIUSRP2922, which is National Instruments Universal Software Radio Peripheral. The paper has three sections in first section, Introduction, the OFDM fundamentals and PAPR are defined in design perspective, in second section conventional and proposed PTS schemes have been explained. The third section consists of result and conclusion.

Analysis and Development of Marketing for the Creative Industry of West Sumatra Based on E-Commerce with the Concept of Customer Relationship Management (Crm) (Analisa Dan Pengembangan Pemasaran Industri Kreatif Sumatera Barat Berbasis E-Commerce Dengan K

West Sumatra is an area in Indonesia that has many Creative Industries, this is the reason the government places representatives of the Ministry of Creative Industries in this region. This is done to foster, oversee and develop the Creative Industries that exist today. The Creative Industries that exist today are very diverse there are 15 fields that are very potential to be developed in Indonesia, Advertising (Advertising), Architecture, Art Goods Market, Crafts (Craf), Design, Video, Film, Photography, Interactive Games (Games), Music , Performing Arts (Showbiz), Publishing and Printing, Computer and Software Services, Television and Radio (Broadcasting), Research and Development (R&D), Culinary. Of the 15 creative industries in Indonesia for the West Sumatra region there are 9 sub-sectors of potential creative industries, namely, fashion, culinary, handicraft, music, performing arts, photography, design, animation, and film, but not all creative industry sectors it is developing so that it has an impact on the marketing of its products. For this reason, it is necessary to analyze and develop the marketing of creative industries in West Sumatra that prioritizes the concept of Customer Relationship Management (CRM) so that marketing concepts that have the potential to increase marketing of creative industry products will be known. Especially now that the Provincial Government is developing the Halal Tourism Industry, of course in this field there a re very many opportunities for the development of the Creative Industries

Spectrum sensing and communication functionalities verification in cognitive radio

SummaryThis paper is intended to discuss hardware setup implementation for realizing the spectrum sensing and communication functionalities of a five‐port integrated ultrawideband and narrowband antenna system. The five‐port integrated antenna system consists of one ultrawideband antenna and four narrowband antennas. The ultrawideband antenna is used for spectrum sensing in cognitive radio, whereas the four narrowband antennas are used for communication. In order to validate functionalities of the antennas, their spectrum sensing and communication performance is verified using an arbitrary waveform generator, real‐time signal analyzer, and Universal Software Radio Peripheral. The ultrawideband antenna is able to sense the various frequencies transmitted by the arbitrary waveform generator. These transmitted signals from the arbitrary waveform generator are treated as busy spectrum channels in the cognitive radio environment. The narrowband antennas are able to perform communication by transmitting the signals at identified spectrum holes. The sensed signals are observed on a real‐time signal analyzer, and the communication signals are viewed in LabVIEW software for which a real‐time signal reception algorithm is used. This signal reception is performed using Universal Software Radio Peripheral.