Universal Software Radio Peripheral N210 Research Articles

Software Defined Radio: USRP N210 with GNU Radio

Driven by the increasing interest from the research community, this paper presents the current role of software defined radio (SDR) in academic and commercial applications which is helpful for the researchers, professors as well as students working in the area of signal processing and wireless communication. The authors mainly focus on universal software radio peripheral (USRP) N210 which is employed as hardware and GNU Radio as software to implement SDR for various applications that help the researchers to test and analyze various proposed techniques for different systems. Furthermore, this paper presents the implementation of basic analog/digital modulation techniques, and recent research works carried out by using SDR. This paper also presents several limitations and current usage of SDR in commercial and academic applications.

Experimental Validation of Spectrum Sensing on Various Transceivers Using Software Defined Radio

Cognitive radio (CR) and software-defined radio (SDR) system technologies provide added flexibility and offer improved spectrum efficiency. Cognitive radio is an obstreperous radio communication and networking technology. It is presently undergoing drastic development due to its potential to resolve many of the problems affecting existing systems. Spectrum sensing is the crucial in empowering technology of CR to sense the existence of primary users or licensed user signals and exploit the spectrum holes. Hence, this paper addresses the design of Energy detection spectrum sensing technique for 16-QAM and 64-QAM transceivers employing SDR testbed. In addition, this paper also addresses the practical signal detection and the impact of various filtering windowing methods on detected signals. Furthermore, the impact of different simulation channels such as dynamic channel model and frequency selective faded channel models with Rayleigh and Rician fadings, are presented by testing the spectrum sensing technique on differential phase shift keying transceiver. For practical proof of the concepts, experimental tests are performed using SDR testbed that employs universal software radio peripheral N210 as hardware platform and GNU Radio as an open source free software platform. Therefore, I have reduced the cost of implementation drastically.

Studying the Parameters of Frequency Dispersion for Radio Links of Different Length Using Software‐Defined Radio Based Sounding System

AbstractMethods and relevant software were developed to study frequency dispersion parameters of wideband high‐frequency (HF) radio channels over propagation paths of different lengths: near vertical incidence skywave paths (up to 500 km) and long‐distance radio paths (from 1,000 up to 3,500 km). We developed a universal ionosonde (in terms of methods and signals) to do experimental research into HF radio wave propagation and dispersion using software‐defined radio technology and platform Universal Software Radio Peripheral N210. The multipurposeness of the ionosonde is manifested in the sounding methods used (oblique incidence and vertical incidence) as well as in the spread spectrum signals used (binary phase shift keying, frequency modulated continuous wave, and frequency modulated interrupted continuous wave). The characteristics of the megahertz‐bandwidth HF channels were studied. The dependences of the variation of the third‐order dispersion parameter on the time of day, the radio path length, and the channel carrier frequency were experimentally found.

Experimental Validation of Timing, Frequency and Phase Correction of Received Signals Using Software Defined Radio Testbed

Recently, almost all the wireless devices are being designed for the fast evolving technology of software-defined radios, which is a radio access technology that most of the signal processing components are implemented digitally in software rather than in hardware to redefine the functionality of components, reduce the cost and complexity of the systems. This paper presents a low cost, portable, and flexible frequency hopping signal record and playback system based on a general purpose software radio front end, the Universal Software Radio Peripheral N210 devices. Further, this paper addresses the different issues such as timing recovery, phase recovery and frequency correction. In addition to that various GNU schematics are created to show the effect of different signal processing blocks on a modulated signal and their corresponding outputs are presented in the view of time domain, frequency domain and waterfall sink.

Experimental validation of orthogonal frequency division multiplexing with peak‐to‐average power ratio reduction and out‐band distortion control using software defined radio

Orthogonal frequency division multiplexing (OFDM) is an emerging technology in recent wireless communication standards where high data rate is required at low latency and better spectral efficiency. OFDM signals have a generic problem of high peak-to-average power ratio (PAPR) due to the superimposition of the data-modulated subcarriers. This high peak signals may result in amplifier non-linearity which creates many problems such as performance degradation and out-of-band distortion. Hence, the authors addressed this problem by designing and implementing four new PAPR reduction schemes such as phase modulation, rail clipping, sample and hold approach and threshold methods based on amplitude clipping to reduce PAPR and improve the band gap between spectral sidelobes to main lobe significantly. For practical proof of the suggested concepts, they have chosen software-defined radio as an experimental setup in which universal software radio peripheral N210 employed as hardware and GNU radio as software. Experimental results are analysed in terms of significant PAPR reduction and out-of-band spectral leakage control. Besides these, motivation, background and relevant mathematical analysis with rigid justification are presented in this study.

Packet data transmission in worldwide interoperability for microwave access with reduced peak to average power ratio and out‐band distortion using software defined radio

The high peaks of a conventional orthogonal frequency division multiplexing (OFDM) symbol may push the amplifier into the non-linear region, which creates many problems that reduce performance and lead to out of band distortion. In this study, the authors present and analyse four different peak to average power ratio (PAPR) reduction techniques such as phase modulation, rail clipping, sample and hold approach and threshold method for packet data transmission of OFDM on mobile-worldwide interoperability for microwave access system. The performance of each PAPR reduction technique on OFDM system is presented in time and frequency domains separately. Therefore an existing OFDM system can provide an additional CE-OFDM mode with relative ease, particularly for the case of software defined platforms. Nowadays, the behaviour of a communication system has been modified by simply changing its software. This gave rise to a new radio model called software defined radio, in which all hardware components are implemented in software rather than in hardware. For our investigation, GNU radio and universal software radio peripheral N210 are employed as software and hardware platforms, respectively. It is shown that for a high clipping threshold value, the gap between in-band and out-of-band radiations is maintained well.