scholarly journals Software-defined radio-based HF doppler receiving system

2021 ◽  
Vol 73 (1) ◽  
Author(s):  
Hiroyuki Nakata ◽  
Kenro Nozaki ◽  
Yuhei Oki ◽  
Keisuke Hosokawa ◽  
Kumiko K. Hashimoto ◽  
...  
Keyword(s):  
Analog Circuits ◽  
Software Defined Radio ◽  
Analog Circuit ◽  
Dynamic Range ◽  
Signal To Noise Ratio ◽  
Digital Signal ◽  
Radio System ◽  
Observation Network ◽  
Receiver System ◽  
New System

AbstractHigh-frequency Doppler (HFD) sounding is one of the major remote sensing techniques used for monitoring the ionosphere. Conventional systems for HFDs mainly utilize analog circuits. However, existing analog systems have become difficult to maintain as the number of people capable of working with analog circuits has declined. To solve this problem, we developed an alternate HFD receiver system based on digital signal processing. The software-defined radio (SDR) technique enables the receiver to be set up without the knowledge of analog circuit devices. This approach also downsizes the system and reduces costs. A highly stabilized radio system for both the transmitter and receiver is necessary for stable long-term observations of various phenomena in the ionosphere. The global positioning system disciplined oscillator with an accuracy of $${10}^{-11}$$ 10 - 11 compensates for the frequency stability required by the new receiving system. In the new system, four frequencies are received and signal-processed simultaneously. The dynamic range of the new system is wider (> 130 dB) than that of the conventional system used in HFD observations conducted by the University of Electro-Communications in Japan. The signal-to-noise ratio significantly improved by 20 dB. The new digital system enables radio waves to be received with much smaller amplitudes at four different frequencies. The new digital receivers have been installed at some of the stations in the HFD observation network in Japan and have already captured various ionospheric phenomena, including medium-scale traveling ionospheric disturbances and sudden commencement induced electric field fluctuations, which indicates the feasibility of SDR for actual ionospheric observations. The new digital receiver is simple, inexpensive, and small in size, which makes it easy to deploy new receiving stations in Japan and elsewhere. These advantages of the new system will help drive the construction of a wide HFD observation network. Graphical Abstract

scholarly journals Software-Defined-Radio Based HF Doppler Receiving System

2021 ◽  
Author(s):  
Hiroyuki Nakata ◽  
Kenro Nozaki ◽  
Yuhei Oki ◽  
Keisuke Hosokawa ◽  
Kumiko Hashimoto ◽  
...  
Keyword(s):  
Analog Circuits ◽  
Software Defined Radio ◽  
Analog Circuit ◽  
Dynamic Range ◽  
Signal To Noise Ratio ◽  
Digital Signal ◽  
Radio System ◽  
Observation Network ◽  
Receiver System ◽  
New System

Abstract High-frequency Doppler (HFD) sounding is a major remote sensing technique for monitoring the ionosphere. Conventional systems for HFDs mainly utilize analog circuits. However, existing analog systems have become difficult to maintain as the number of individuals adept at working with analog circuits has declined. To solve this problem, we developed an alternate HFD receiver system based on digital signal processing. The software-defined radio (SDR) technique enables the receiver to be set up without the knowledge of analog circuit devices. This approach also downsizes the system and reduces costs. A highly stabilized radio system for both the transmitter and receiver is necessary for stable long-term observations of various phenomena in the ionosphere. The global positioning system disciplined oscillator with an accuracy of H compensates for the frequency stability required by the new receiving system. In the new system, four frequencies are received and signal-processed simultaneously. The dynamic range of the new system is wider (> 130 dB) than that of the conventional system. The signal-to-noise ratio significantly improved by 20 dB. The new digital system enables radio waves to be received with much smaller amplitudes at four different frequencies. New digital receivers have been installed at some of the stations in the HFD observation network in Japan and have already captured various ionospheric phenomena, including medium-scale traveling ionospheric disturbances and sudden commencement induced electric field fluctuations, which indicates the feasibility of SDR for actual ionospheric observations. The new digital receiver is simple, inexpensive, and small in size, which makes it easy to deploy new receiving stations in Japan and elsewhere. These advantages of the new system will help drive the construction of a wide HFD observation network.

A High-Performance Signal Processing System for Monopulse Tracking Radar

2011 ◽  
Vol 383-390 ◽  
pp. 471-475
Author(s):  
Yong Bin Hong ◽  
Cheng Fa Xu ◽  
Mei Guo Gao ◽  
Li Zhi Zhao
Keyword(s):  
Signal Processing ◽  
High Performance ◽  
Dynamic Range ◽  
Signal To Noise Ratio ◽  
Processing System ◽  
Digital Signal ◽  
Radar Signal ◽  
Signal Processing System ◽  
Parallel Pipelined ◽  
Tracking Radar

A radar signal processing system characterizing high instantaneous dynamic range and low system latency is designed based on a specifically developed signal processing platform. Instantaneous dynamic range loss is a critical problem when digital signal processing is performed on fixed-point FPGAs. In this paper, the problem is well resolved by increasing the wordlength according to signal-to-noise ratio (SNR) gain of the algorithms through the data path. The distinctive software structure featuring parallel pipelined processing and “data flow drive” reduces the system latency to one coherent processing interval (CPI), which significantly improves the maximum tracking angular velocity of the monopulse tracking radar. Additionally, some important electronic counter-countermeasures (ECCM) are incorporated into this signal processing system.

scholarly journals Selection and Application of the Data Transfer Operating Protocol Software Architecture for the Software-Defined Radio

2019 ◽  
Vol 22 (4) ◽  
pp. 18-30
Author(s):  
Oleg V. Vorobyov ◽  
Alexey I. Rybakov
Keyword(s):  
Signal Processing ◽  
Digital Signal Processing ◽  
Software Architecture ◽  
Software Defined Radio ◽  
Communication Systems ◽  
Digital Signal ◽  
Transmission Protocol ◽  
Radio System ◽  
Functional Description ◽  
System Layout

Introduction. The demodulator structure is described and decoding algorithm for signal-code constructions development is presented. The structure and functional description of the developed software (SW), which is designed for the installation of the software-defined radio in the radio stations layout, are presented. The frame structures of the broadcast and half-duplex protocols, modulation/demodulation and subsequent digital signal processing in existing and prospect radio communication systems are considered.Objective. Investigation of modulation/demodulation methods and subsequent digital signal processing along with requirements imposed by them on the network stations equipment and system operation algorithms.Materials and methods. The software for the software-defined radio system layout is developed to demonstrate the reliability and operability of the proposed algorithm and transmission protocol. It can be used to receive and transmit information by using ionospheric reflections. Present design takes into account existing standards and amateur systems such as WinLink and information systems (digital and analog) for the "physical" and "channel" levels.Results. The structure and functional description of the developed software for the software-defined radio system layout are given. The possible realization of the software-defined radio channel for data receiving and transfer by using ionospheric reflections is presented. The results of technical solutions experimental testing are shown. The software can use hardware and software to control the transceiver module, which includes the SunSDR2 transceiver and antenna amplifier.Conclusion. The structure and functional description of the developed software are presented as a result of the software architecture selection and its application investigation. It is concluded that the reliability and operability justification of the proposed algorithm and transmission protocol is relevant in a field of the digital receivers development for communication systems of various purposes. The presented experimental studies data on verification of the proposed algorithm show the feasibility of present solutions on the qualitative utilization of the channel resource by using the described code structure. The present results allow to determine the most appropriate and efficient way of the software development allowing to create a technique that can meet the maximum number of possible assignments of radio access channels.

scholarly journals A Novel Sigma-Delta Modulator with Fractional-Order Digital Loop Integrator

2017 ◽  
Vol 2017 ◽  
pp. 1-7
Author(s):  
Chi Xu ◽  
Yu Jin ◽  
Duli Yu
Keyword(s):  
Fractional Order ◽  
Analog Circuit ◽  
Dynamic Range ◽  
Signal To Noise Ratio ◽  
Sigma Delta Modulator ◽  
Sigma Delta ◽  
Integer Order ◽  
Noise Characteristics ◽  
Chip Testing ◽  
Sigma Delta Adc

This paper proposes using a fractional-order digital loop integrator to improve the robust stability of Sigma-Delta modulator, thus extending the integer-order Sigma-Delta modulator to a non-integer-order (fractional-order) one in the Sigma-Delta ADC design field. The proposed fractional-order Sigma-Delta modulator has reasonable noise characteristics, dynamic range, and bandwidth; moreover the signal-to-noise ratio (SNR) is improved remarkably. In particular, a 2nd-order digital loop integrator and a digital PIλDμ controller are combined to work as the fractional-order digital loop integrator, which is realized using FPGA; this will reduce the ASIC analog circuit layout design and chip testing difficulties. The parameters of the proposed fractional-order Sigma-Delta modulator are tuned by using swarm intelligent algorithm, which offers opportunity to simplify the process of tuning parameters and further improve the noise performance. Simulation results are given and they demonstrate the efficiency of the proposed fractional-order Sigma-Delta modulator.

scholarly journals A Novel Design of Matched Filter for Digital Receivers

2019 ◽  
Vol 8 (3) ◽  
pp. 6000-6003
Keyword(s):  
Pulse Compression ◽  
Filter Design ◽  
Matched Filter ◽  
Signal To Noise Ratio ◽  
Digital Signal ◽  
Receiver System ◽  
Digital Pulse ◽  
Pros And Cons ◽  
Processing Techniques ◽  
Digital Receivers

In this paper, a brief review regarding introduction to the digital signal processing techniques particularly Digital Pulse Compression and Linear Frequency Modulation involved in matched filtering and some designs being used is presented. Also, the matched filter being developed is discussed by highlighting its pros and cons. The introduction of matched filter in the communication receivers has simplified the design of the system. The matched filter has improved the signal to noise ratio of the receiver system and hence has become an important element in the communication system. This paper also presents the possible challenges; the matched filter design and simulation results in MATLAB have shown satisfactory outputs of the receiver.

scholarly journals High Precision Multiplier for RNS {2n−1,2n,2n+1}

Electronics ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1113
Author(s):  
Shang Ma ◽  
Shuai Hu ◽  
Zeguo Yang ◽  
Xuesi Wang ◽  
Meiqing Liu ◽  
...  
Keyword(s):  
High Precision ◽  
Dynamic Range ◽  
Signal To Noise Ratio ◽  
Digital Signal ◽  
Number System ◽  
Residue Number System ◽  
Extra Effort ◽  
Scale Down ◽  
Weighted Number ◽  
Dsp Systems

The Residue Number System (RNS) is a non-weighted number system. Benefiting from its inherent parallelism, RNS has been widely studied and used in Digital Signal Processing (DSP) systems and cryptography. However, since the dynamic range in RNS has been fixed by its moduli set, it is hard to solve the overflow problem, which can be easily solved in Two’s Complement System (TCS) by expanding the bit-width of it. For the multiplication in RNS, the traditional way to deal with overflow is to scale down the inputs so that the result can fall in its dynamic range. However, it leads to a loss of precision. In this paper, we propose a high-precision RNS multiplier for three-moduli set 2n−1,2n,2n+1, which is the most used moduli set. The proposed multiplier effectively improves the calculation precision by adding several compensatory items to the result. The compensatory items can be obtained directly from preceding scalers with little extra effort. To the best of our knowledge, we are the first one to propose a high-precision RNS multiplier for the moduli set 2n−1,2n,2n+1. Simulation results show that the proposed RNS multiplier can get almost the same calculation precision as the TCS multiplier with respect to Mean Square Error (MSE) and Signal-to-Noise Ratio(SNR), which outperforms the basic scaling RNS multiplier about 2.6–3 times with respect to SNR.

scholarly journals Apsu: a wireless multichannel receiver system for surface-NMR groundwater investigations

2018 ◽  
Author(s):  
Lichao Liu ◽  
Denys Grombacher ◽  
Esben Auken ◽  
Jakob Juul Larsen
Keyword(s):  
Data Acquisition ◽  
Dynamic Range ◽  
Dead Time ◽  
Signal To Noise Ratio ◽  
Noise Cancellation ◽  
Low Noise ◽  
Dipole Source ◽  
Central Unit ◽  
Long Distance ◽  
Receiver System

Abstract. Surface nuclear magnetic resonance (surface-NMR) has the potential to be an important geophysical method for groundwater investigations, but the technique suffers from poor signal-to-noise ratio (SNR) and long measurement times. We present a new wireless, multichannel surface-NMR receiver system (called Apsu) designed to improve SNR, field deployability and minimize instrument dead time. It is a distributed wireless system consisting of a central unit and independently operated data acquisition boxes each with three channels that measure either the NMR signal or noise for reference noise cancellation. Communication between the central unit and the data acquisition boxes is done through long distance WiFi and recordings are retrieved in real time. The receiver system employs differential coils with low-noise pre-amplifiers and high-resolution wide dynamic range acquisition boards. Each channel contains multi-stage amplifiers, short settling-time filters and two 24-bit analog-to-digital converters in dual-gain mode sampling at 31.25 kHz. The system timing is controlled by GPS clock and sample jitter between channels is less than 12 ns. Separated transmitter/receiver coils and continuous acquisition allow NMR signals to be measured with zero instrument dead time. In processed data, analog and digital filters causes an effective dead time of 4 ms. Synchronization with an independently operated transmitter system is done with a current probe monitoring the NMR excitation pulses. The noise density measured in a shorted-input test is 1.8 nV/√(Hz). We verify the accuracy of the receiver system with measurements of a magnetic dipole source and by comparing our NMR data with data obtained using an existing commercial instrument. The applicability of the system for reference noise cancellation is validated with field data.

scholarly journals Agile multi-beam front-end for 5G mm-wave measurements

2021 ◽  
pp. 1-11
Author(s):  
Steffen Spira ◽  
Kurt Blau ◽  
Reiner Thomä ◽  
Matthias A. Hein
Keyword(s):  
Integrated Circuits ◽  
Antenna Array ◽  
Analog Circuits ◽  
Analog Circuit ◽  
Digital Signal ◽  
Research Unit ◽  
Phase Shifters ◽  
Error Vector Magnitude ◽  
Wave Measurements ◽  
New Radio

Abstract The 5th generation new radio (5G NR) standards create both enormous challenges and potential to address the spatio-spectral-temporal agility of wireless transmission. In the framework of a research unit at TU Ilmenau, various concepts were studied, including both approaches toward integrated circuits and distributed receiver front-ends (FEs). We report here on the latter approach, aiming at the proof-of-principle of the constituting FEs suitable for later modular extension. A millimeter-wave agile multi-beam FE with an integrated 4 by 1 antenna array for 5G wireless communications was designed, manufactured, and verified by measurements. The polarization is continuously electronically adjustable and the directions of signal reception are steerable by setting digital phase shifters. On purpose, these functions were realized by analog circuits, and digital signal processing was not applied. The agile polarization is created inside the analog, real-time capable FE in a novel manner and any external circuitry is omitted. The microstrip patch antenna array integrated into this module necessitated elaborate measurements within the scope of FE characterization, as the analog circuit and antenna form a single entity and cannot be assessed separately. Link measurements with broadband signals were successfully performed and analyzed in detail to determine the error vector magnitude contributions of the FE.

Performance of Chaotic CDMA System implemented on Software-Defined Radio System

2014 ◽  
Vol 1 ◽  
pp. 662-665
Author(s):  
Hisashi Watanabe ◽  
Yuichi Omori ◽  
Mikio Hasegawa ◽  
Kazuyuki Aihara
Keyword(s):  
Software Defined Radio ◽  
Cdma System ◽  
Radio System
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