Software Defined Radio Transceiver Research Articles

IQ Imbalance Correction in Wideband Software Defined Radio Transceivers

IQ Imbalance Correction in Wideband Software Defined Radio Transceivers

Novel Real-Time Decision-Based Carrier Tracking for Software-Defined Radios Using M-ARY QAM Modulation

In this paper, a scalable and real-time decision-based carrier tracking for software defined radio (SDR) for M-ary QAM modulation has been proposed and tested in real-time using the universal software radio peripheral (USRP)-2922. The proposed system provides real-time decision-based carrier tracking for improved efficiency and performance. The real-time transfer of data has been done using the USRP-2922 hardware using the M-ary QAM modulation scheme for data transmission. The novelty of the proposed system is that one can transfer random data (binary bits), text or an image which can be encoded using the desired forward error correction codes (FEC) namely the convolution coding/Viterbi soft decision decoding and the turbo coding/decoding. The proposed novel SDR transceiver system with real-time decision-based carrier tracking shows an improved performance for different parameters such as the bit error rate (BER) and signal to noise ratio (Eb/No).

Machine Learning Modeling of GPS Features with Applications to UAV Location Spoofing Detection and Classification

In this paper, machine learning (ML) modeling is proposed for the detection and classification of global positioning system (GPS) spoofing in unmanned aerial vehicles (UAVs). Three testing scenarios are implemented in an outdoor yet controlled setup to investigate static and dynamic attacks. In these scenarios, authentic sets of GPS signal features are collected, followed by other sets obtained while the UAV is under spoofing attacks launched with a software-defined radio (SDR) transceiver module. All sets are standardized, analyzed for correlation, and reduced according to feature importance prior to their exploitation in training, validating, and testing different multiclass ML classifiers. The resulting performance evaluation of these classifiers shows a detection rate (DR), misdetection rate (MDR), and false alarm rate (FAR) better than 92%, 13%, and 4%, respectively, together with a sub-millisecond detection time. Hence, the proposed modeling facilitates accurate real-time GPS spoofing detection and classification for UAV applications.

Tunable Filtenna With DGS Loaded Resonators for a Cognitive Radio System Based on an SDR Transceiver

This paper introduces the design of a filtenna for cognitive radio systems. Four varactor diodes, which are inserted in the bandpass filter, are used to achieve the desired tunability. The proposed bandpass filter is integrated with a wideband monopole antenna. The bandpass filter is achieved by using two coupled defected ground structure (DGS) resonators and two coupled microstrip lines ended with two stubs. The monopole antenna is designed to operate in a frequency band from 1.3 GHz to 3 GHz. The four varactor diodes are used to tune the antenna resonance frequency from 2.7 GHz to 2 GHz when the capacitance increases from 1.55 pF to 2.67 pF. The performance of the proposed filtenna is validated by simulation and measurements from a fabricated prototype. Finally, the proposed filtenna is tested using the Software Defined Radio (SDR) platform bladeRF. This transceiver can transmit and receive in a wide frequency range of 0.3 GHz up to 3.8 GHz, which makes it suitable for testing the proposed reconfigurable filtenna.

Designing a Secure Software-Defined Radio Transceiver using the Logistic Map

The need to exchange large amounts of real-time data is constantly increasing in wireless communication. While traditional radio transceivers are not cost-effective and their components should be integrated, software-defined radio (SDR) ones have opened up a new class of wireless technologies with high security. This study aims to design an SDR transceiver was built using one type of modulation, which is 16 QAM, and adding a security subsystem using one type of chaos map, which is a logistic map, because it is a very simple nonlinear dynamical equations that generate a random key and EXCLUSIVE OR with the originally transmitted data to protect data through the transmission. At the receiver, the data will be recovered using the same key, the received data is the same at the sender, so this result shows that the transceiver work normally and calculates the BER at the end each time the SNR changed. Our results indicate that the designed transmitter and receiver perform as usual and finally calculate the bit error rate when the signal to noise ratio is changed. The evaluation of BER indicates that simulated values are smaller than theoretical ones obtained using the BER tool. when SNR is equivalent to 7 dB, the theoretical and simulated BER obtained is 0.01695 and 0.00199, respectively. Designing soft defined radio transceiver using MATLAB R 2011a and system generator ISE14.1/SIMULINK.

A city-wide experimental testbed for the next generation wireless networks

To facilitate research in dynamic spectrum access, 5G, vehicular networks, underground wireless communications, and radio frequency machine learning, a city-wide experimental testbed is developed to provide realistic radio environment, standardized experimental configurations, reusable datasets, and advanced computational resources. The testbed contains 5 cognitive radio sites, and covers 1.1 square miles across two campuses of the University of Nebraska-Lincoln and a public street in the city of Lincoln, Nebraska. Each site is equipped with a 4x4 MIMO software-defined radio transceiver with 20Gbps fronthaul connectivity. Additional cognitive radio transceivers with an underground 2x2 MIMO antenna are included in a site. High speed fronthaul network based on dedicated fiber connects the 5 sites to a cloud-based central unit for data processing and storage. The testbed provides researchers rich computational resources such as arrays of CPUs and GPUs at the cloud and FPGAs at both the edge and fronthaul network. Developed via the collaboration of the university, city, and industrial partners, this testbed will facilitate education and researches in academic and industrial communities.

Comparison of Baseband Processors in Terms of Realization SDR-Transceivers

Software-defined Radio is a programmable transceiver with the capability of operating various wireless communication protocols without the need to change or update the hardware. Consequently, Software-defined Radio has earned a lot of attention and is of great significance to both academia, military and aerospace industry. Components of Software-defined Radio (e.g. mixers, filters, amplifiers, modulators/demodulators, detectors, etc.) implemented by means of software on a personal computer or embedded system. Operation of signal processing are handed over to the baseband processor, rather than being done in special electronic circuits. Baseband processors are implemented through employing various types of hardware platforms, such as General Purpose Processors, Graphics Processing Units, Digital Signal Processors, and Field Programmable Gate Arrays. Each of these platforms is associated with their own set of advantages and disadvantages. In this paper was proposed a comparison of the state-of-the-art hardware platforms in the context of implementation Software-defined Radio transceivers. For comparison was determined as follow criteria: computational power of hardware platform, power consumption, complexity of developing, and cost of tools and equipment. First approaches to realizing baseband processors is using a General Purpose Processor and accelerating by Graphics Processing Units. But General Purpose Processor and Graphics Processing Units execute software instructions in the sequential order. For this reason, General Purpose Processors are not convenient for high-throughput computing with real-time requirements. Also this hardware platforms have increased power consumption. This aspect does not allow use General Purpose Processor and Graphics Processing Units in small and portable Software-defined Radio transceivers. In other hand, General Purpose Processors are preferable hardware platform by researchers and beginners due to their flexibility and programmability. Therefore, General Purpose Processors and Graphics Processing Units is highly recommended for prototyping Software-defined Radio platforms. Digital Signal Processor was reviewed as alternative approach for implementing baseband processors. Digital Signal Processors is a particular type of General Purpose Processors that is optimized to process digital signals. Digital Signal Processors have similar disadvantage with insufficient computational power, but some manufacturer sell energy optimized Digital Signal Processors. Consequently, Digital Signal Processor is commonly used in small and portable Software-defined Radio transceivers. Field Programmable Gate Arrays and System-on-Chips with Field Programmable Gate Array are strongly recommended for high-performance Software-defined Radio platforms. This hardware platforms combine the flexibility of processors and efficiency of small Digital Signal Processor. Field Programmable Gate Arrays can achieve a high level of parallelism in executing digital signal processing. However, the designers must have a high degree in digital electronics and good acknowledgement of hardware description languages. After the research, was proposed own flexible architecture Software-defined Radio transceiver and methods for development.

Software-Defined Radio Transceiver Design Using FPGA-Based System-on-Chip Embedded Platform With Adaptive Digital Predistortion

In this paper, a software-defined radio (SDR) based transceiver system is designed and implemented on the system-on-chip (SoC) platform, which consists of a high-speed Arm embedded processor and a reconfigurable field-programmable gate array (FPGA). In the proposed SDR transceiver, the real-time baseband signal generation and adaptive digital predistortion (ADPD) units are implemented on the SoC platform. Memory polynomial model based ADPD solution is implemented to linearize the radio frequency (RF) power amplifiers (PAs). The implementation of the ADPD on a reconfigurable FPGA platform makes the system flexible and cost-effective. The PA characterization, in terms of model extraction and coefficient calculation, is done in real-time. These calculated coefficients are updated in the transmission path to precondition the transmitted signal before it is applied to the PA. The proposed ADPD is applied at the baseband level. Therefore, it can be used for different classes of PA operating at different RF carrier frequencies. A long-term evolution (LTE) signal with 20 MHz bandwidth and 11 dB peak to average power ratio (PAPR) is used for simulation and measurement purposes. The LTE signal is amplified using a GaN-based harmonically tuned continuous Class-F PA in measurement. The performance of the implemented ADPD scheme is analyzed in terms of NMSE, ACPR and EVM.

Принципы и технологии цифровой связи на основе программно-конфигурируемого радио: обзор современных тенденций в области создания комплекса подготовки специалистов

Current trends in software-defined radio (SDR) penetration into science, production and education is determined by the appearance on the market of affordable and multifunctional software and hardware solutions. Analysis of the experience of a number of foreign universities suggests a new educational paradigm in the field of telecommunications and radio communications related to the direction of the SDR. From an educational point of view, the field of the SDR is interdisciplinary and covers the following courses: radio receiving and radio transmitting devices, digital signal processing, theory of electrical communication, programming and simulation modeling. The integrating role of the SDR course is to develop a system approach for analyzing and synthesizing a modern transceiver with the ability to programmatically implement most of the functions of the physical layer and with final approbation of its work in real field conditions. The purpose of this work is to review current trends in the creation of a curriculum for training specialists in the course “Principles and Technologies of Digital Communication Based on Software Defined Radio”. Thus the work analyzes architecture and evolution of the SDR radio station, current trends and foreign experience in the use of SDR in education, the hardware structure of the radio receiver RTL-SDR, features of the implementation of the SDR transceiver in open source software. To assess the performance indicators of the SDR transceivers, the conclusion contains approach for half-natural experiment testing on the Keysight test bench.

Waveform diversity for mutual interference mitigation in automotive radars under realistic traffic environments

This paper presents a novel approach for mutual interference mitigation in automotive radars based on advanced waveform design by imposing time and frequency diversity to frequency modulated continuous wave (FMCW) chirp signal. Performance of the proposed waveform has been investigated using software-defined radio transceiver, and measurement results are provided. The system concept is validated by developed automotive radar channel model considering realistic 3D road traffic scenario using a ray-tracing tool. Theoretical analysis and simulation examples of mutual interference scenarios in automotive environment are provided to evaluate the effectiveness of the proposed method. Performance of both conventional FMCW waveform and proposed waveform under mutual interference environments has been provided for fair comparison. Results show that the proposed system is able to detect the targets of interest successfully while mitigates the false targets in mutual interference environments.

Can software defined radio be used to compromise ADS-B aircraft transponder signals?

Air traffic control is moving from independent primary surveillance radar to the automatic dependent surveillance-broadcast (ADS-B) system. This holds the potential of reducing the total cost of deployment and improving the detection accuracy of aircraft. However, as currently being deployed these systems lack strong security mechanisms and are susceptible to a variety of radio frequency attacks. These attacks have been proffered by attackers at hacker conventions and by academic researchers. And many online sites even provide hacking “how-to” instructions on ADS-B. Is it possible for an attacker to manipulate ADS-B to interfere with an aircraft in flight using readily available tools? Using a basic $200 software defined radio (SDR) transceiver we simulated an ADS-B replay attack. Despite the advancement in SDR we find that the quality of SDR transceivers are still insufficient to perform a replay attack.

A 0.4–3-GHz nested bandpass filter and a 1.1–1.7-GHz balun bandpass filter using tunable band-switching technique

This paper presents a second-order tunable single-ended (unbalanced) bandpass filter (BPF) with continuous 0.4–3-GHz coverage and a tunable balun BPF with continuous 1.1–1.7-GHz coverage for software-defined radio transceivers with the use of band-switchable and radio frequency (RF)-micro-electromechanical systems (MEMS)-tuned resonators. The BPFs are realized with two pairs of RF switches for coarse-tuning and RF-MEMS-tunable capacitors for fine-tuning. On the one hand, for the tunable single-ended BPF, a transition between three bands is enabled using two pairs of RF switches. On the other hand, for the tunable balun BPF, a transition between two bands is enabled using one pair of RF switches. Furthermore, the three-band switchable single-ended BPF is constructed in a nested two-filter bank structure for expanding the tuning range without increasing the footprint. In addition, to complement the discrete band gaps, RF-MEMS capacitor-tuned resonators are used, and a continuous tuning range of nearly the entire ultra-high-frequency band is achieved. The filter bank is fabricated on a Duroid substrate with εr = 3.5 and h = 0.787 mm. The filter bank has an insertion loss of 3.2–6.8 dB and a 1-dB bandwidth of 65–450 MHz with a continuous tuning range of 0.4–3 GHz.

Low-cost approach for a software-defined radio based ground station receiver for CCSDS standard compliant S-band satellite communications

A major concern of a university satellite mission is to download the payload and the telemetry data from a satellite. While the ground station antennas are in general easy and with limited afford to procure, the receiving unit is most certainly not. The flexible and low-cost software-defined radio (SDR) transceiver "BladeRF" is used to receive the QPSK modulated and CCSDS compliant coded data of a satellite in the HAM radio S-band. The control software is based on the Open Source program GNU Radio, which also is used to perform CCSDS post processing of the binary bit stream. The test results show a good performance of the receiving system.

High isolation wideband CMOS T/R switch with leakage cancellation technique for software-defined radio transceiver

0.1---3 GHz high isolation wideband CMOS Transmit/Receiver (T/R) switch is presented for software-defined radio (SDR) transceiver. The independent bias technique is proposed to keep the transistors in ideal ON/OFF mode to improve power handling capacity. The leakage cancellation technique with two matched paths is introduced to cancel the leakage from TX port to RX port. The proposed T/R switch has been implemented in 65 nm CMOS. The measured results show that the differential T/R switch achieves 23dBm 1-dB compression point (P1dB) and features 50---70 dB isolation.

Guest Editorial for the Special Issue on Software-Defined Radio Transceivers and Circuits for 5G Wireless Communications

Yichuang Sun, Baoyong Chi, and Heng Zhang, Guest Editorial for the Special Issue on Software-Defined Radio Transceivers and Circuits for 5G Wireless Communications, published in IEEEE Transactions on Circuits and Systems II: Express Briefs, Vol. 63 (1): 1-3, January 2016, doi: https://doi.org/10.1109/TCSII.2015.2506979.

Design of a hybrid reconfigurable Software Defined Radio transceiver based on frequency shift keying using multiple encoding schemes

Software Defined Radio (SDR) is the technology which has given researchers the opportunity and flexibility of integration and intercommunication of existing and future networks together. The radio spectrum is the most vital resource for a mobile operator in today’s world of modern wireless communications. After analyzing the spectrum allocation map one can conclude that the most of the prime spectrums falling under the licensed bands have already been allocated for licensed users for exclusive use. There are very few unlicensed bands for the unlicensed users. SDR offers a perfect solution to this problem of spectrum scarcity being experienced in wireless communication systems. The demand for reliable, high data rate transmission has increased significantly these days, which leads the way to adoption, of different digital modulation techniques.The aim of this paper was to analyze Frequency Shift Keying (FSK) Transceiver built using Laboratory Virtual Instrumentation Engineering Workbench (LabVIEW) and to measure the reduction in data errors in the presence of Forward Error Correction (FEC) channel coding algorithms namely the Convolution and the Turbo Codes. Through this design a graphical representation of Bit Error Rate (BER) vs Eb/N0 where (Eb) is Energy per bit and (N0) is Spectral noise density has been given in the presence of Additive White Gaussian Noise (AWGN) introduced in the channel. FSK is widely used for data transmission over band pass channels; hence, we have chosen FSK for the implementation of SDR. The SDR transceiver module designed has been fully implemented and has the ability to navigate over a wide range of frequencies with programmable channel bandwidth and modulation characteristics. We are able to build an interactive FSK based SDR transceiver in a shorter time with the use of LabVIEW. The outputs achieved show a low BER for very high data rates in the presence of AWGN noise.

Coarse Grained ADRES Based MIMO-OFDM Transceiver with New Radix- $${2}^{5}$$ 2 5 Pipeline FFT/IFFT Processor

Software defined radio (SDR) is an adaptive radio that sense and adjust the operating parameters based on the environment. MIMO-OFDM technique based SDR transceiver is an advanced technique over the conventional radio system in terms of complex adaptation strategies. To improve the performance of the OFDM architecture, a new algorithm was developed for FFT/IFFT unit called the radix-$${2}^{5}$$25 modified booth encoding algorithm. This paper describes the system-on-chip (SoC) implementation of MIMO-OFDM transceiver architecture for SDR. This architecture design is based on the concept of reusing the same software and hardware modules to handle different algorithms with the help of dynamic reconfigurable system. It provides a greater flexibility in the operation of reconfigurable system; also it can able to add new abilities into it, without adding additional hardware. The SoC functional verification of this transceiver circuit was carried out in the Xilinx Virtex 5 FPGA, on top of the ADRES reconfigurable SoC architecture. The result shows that the proposed method provides a greater performance by two times than the previous works. It had provided a high throughput (2.4 Gsample/s) with low latency (2.941 ns) and less area utilization (27k logic gates).

CMOS software-defined radio transceivers: Analog design in digital technology

The introduction of several new cellular and connectivity radio standards has attracted the wireless industry to the concept of softwaredefined radio systems, preferably implemented in advanced nanometer CMOS technology. Several novel circuits and architectures have been investigated to cope with the huge design challenges involved, an overview of which will be given in this article. First, two digitally inspired receiver approaches are presented in detail. Discrete-time radio receivers exploit the paradigm that time is better controllable than voltage in modern CMOS, and are implemented using transistors mainly as switches. RF ADCs digitize the signal as close as possible to the antenna, but still require highspeed analog circuits to achieve the required performance. The second part of the article presents a traditional direct-conversion architecture, including also a transmitter, where several new circuits and architectures are used to exploit as much as possible the capabilities of a modern digital CMOS technology.

Future Software-Defined Radio Platforms and Mapping Flows

A software-defined radio (SDR) system is a radio communication system in which physical layer components are implemented on a programmable or reconfigurable platform. The modulation and demodulation is performed in software and thus the radio is able to support a broad ran: of frequencies and functions concurrently. In the ideal SDR transceiver scheme, an analog-to-digital converter (ADC) and a digital-to-analog converter (DAC) are attached to the antenna. This would imply that a digital signal processor (DSP) is connected to the ADC and the DAC, directly performing signal processing for the streams of data from/to antenna. Today, the ideal SDR transceiver scheme is still not feasible and thus some processing has to happen in the reconfigurable analog front end.

Special Issue on Signal Processing for Software Defined Radio Handsets

The ultimate objective of Software Defined Radio (SDR) is to replace the entire analog signal processing in the wireless transceivers with digital signal processing. This will provide the flexibility, through reconfiguration or reprogramming, to enable the transceivers to work with different air-interfaces standards using a single generic hardware platform. Most of the research in SDR to date has been focused on base stations, which do not have as tight constraints in size and power consumption as handsets. However, in order to realize the promise of integrated services and global roaming capabilities, the design and development of a multi-standard SDR handset with dynamic reconfigurability is crucial. The size and power constraints imposed by handsets with limited resources pose a major design challenge. This special issue brings together 11 papers that address various aspects of this challenge from the perspectives of wireless systems, computing architectures, embedded systems and signal processing. The most important part of an SDR transceiver is the wideband analog-to-digital converter (ADC) that converts the radio frequency signal received by the antenna into digital form for further processing. The first paper, “A multi-mode sigma-delta ADC for GSM/WCDMA/WLAN applications” by Jose et. al. proposed a cascaded reconfigurable sigma-delta modulator that is able to work with three different communication standards. This design, implemented in 0.18 μm CMOS technology, exhibits excellent signal-to-noise plus distortion ratios and has reduced power consumption compared to conventional designs. After ADC, the digitized received signal will need to be separated into signals within the various bands specified by the communication standard. This is performed by the channelizer which has the highest computational requirements of the whole SDR system. The second paper, by Panicker et al., reviews the state-of-the-art filter bank channelizer techniques with low power and dynamic reconfigurability properties. The design of reconfigurable devices can be optimized using the methodology of parametrization which bring together the common aspects of a myriad number of wireless standards into a single processing procedure. In this way, the implementation of the multi-standard SDR will be greatly simplified. “Promising technique of parametrisation for reconfigurable radio, the Common Operators Technique: fundamentals and examples” by Alaus et al. presents the common operator technique for parametrization which is less standards dependent than the more conventional Common Function technique. The direct digitization of the radio frequency (RF) signal requires very high speed ADCs which is not readily available using current technology. Therefore, current SDR implementations typically down-converts the RF A. P. Vinod (*) School of Computer Engineering, Nanyang Technological University, Nanyang, Singapore e-mail: asvinod@ntu.edu.sg