Recent Submissions

Now showing 1 - 5 of 16
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    Multipath Exploitation in Emitter Localization for Irregular Terrains,
    (Společnost pro radioelektronické inženýrství, 2019-06) Dalveren, Yaser; Kara, Ali
    Electronic Support Measures (ESM) systems have many operational challenges while locating radar emitter’s position around irregular terrains such as islands due to multipath scattering. To overcome these challenges, this paper addresses exploiting multipath scattering in passive localization of radar emitters around irregular terrains. The idea is based on the use of multipath scattered signals as virtual sensor through Geographical Information System (GIS). In this way, it is presented that single receiver (ESM receiver) passive localization can be achieved for radar emitters. The study is initiated with estimating candidate multipath scattering centers over irregular terrain. To do this, ESM receivers’ Angle of Arrival (AOA) and Time of Arrival (TOA) information are required for directly received radar pulses along with multipath scattered pulses. The problem then turns out to be multiple-sensor localization problem for which Time Difference of Arrival (TDOA)-based techniques can easily be applied. However, there is high degree of uncertainty in location of candidate multipath scattering centers as the multipath scattering involves diffuse components over irregular terrain. Apparently, this causes large localization errors in TDOA. To reduce this error, a reliability based weighting method is proposed. Simulation results regarding with a simplified 3D model is also presented.
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    A General Hybrid Precoding Method for mmWave Massive MIMO Systems,
    (Společnost pro radioelektronické inženýrství, 2019-06) Xie, Yi; Li, Bo; Yan, Zhongjiang; Fan, Jiancun; Yang, Mao
    Recently, hybrid precoding architectures have been proposed for the purpose of practical implementation of massive Multiple-Input Multiple-Output (MIMO) systems in the Fifth Generation (5G) networks. In this paper, a general precoding method is investigated for Millimeter Wave (mmWave) multi-user systems, which is composed of the designs in analog Radio Frequency (RF) and digital baseband matrices. In the general hybrid architecture, the analog part is constituted of independent analog sub-arrays with full connection inside. The analog precoding matrix is considered by maximizing Signal-to-Leakage-plus-Noise Ratio (SLNR) with only the long-term statistics of user groups. Due to the constant module constraint of RF chains, a supplemental matrix is introduced to reduce the performance loss. The digital precoding matrix performs Regularized Zero-Forcing (RZF) with the reduced amount of effective channels. Finally, simulation results demonstrate the performance improvement of the proposed precoding method. Meanwhile, trade-off between the performance and the complexity is handled well by the proposed method.
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    The Digital Audio Broadcasting Journey from the Lab to Listeners - the Czech Republic Case Study
    (Společnost pro radioelektronické inženýrství, 2019-06) Zyka, Karel
    This paper describes the complex experiences and the results of the Digital Audio Broadcasting (DAB+) implementation in the conditions of the Czech Republic. It analyses the background of the EUREKA 147 program, its targets, and to what extent they were reached. The main focus is concentrated on the evaluation of the real steps which had to be done during the implementation process before the first regular broadcasting could be started and the difficulties encountered. The key point became experimental broadcasting “DAB Prague”. It demonstrated the advantages of this new platform and gave the opportunity to test its functions and physical behavior in real conditions, under the different parameter settings. The important issue is the allocation of the band III by National Regulatory Authority and the capacity of DAB+ multiplexes. The paper also demonstrates the experience from the setup of the DAB+ headend. It describes the content solution in context of using non-entropic audio coding, setting the codec algorithms and the way to use accompanying multimedia services. The results of the tests and measurements presented in this paper were used in the real project of the regular nationwide DAB+ network.
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    Coplanar Waveguide Microwave Sensor for Label-Free Real-Time Glucose Detection
    (Společnost pro radioelektronické inženýrství, 2019-06) Sameer, Mustafa; Agarwal, Poonam
    In this work, a~real-time label-free microwave diagnostic approach using Co-Planar Waveguide (CPW) design has been demonstrated for glucose detection. This mechanism has tremendous potential for the biomedical applications. Here, glucose biosensor is implemented with 50 Ω CPW transmission line, where the centre localized 3 mm diameter of CPW transmission line has been used for the sensing. Glucose sensor is implemented utilizing low cost multilayer PCB and polymer Poly-Di-Methyl-Siloxane(PDMS) fabrication technology. CPW transmission line is fabricated on FR4 microwave laminate board. To confine the Analyte Under Test (AUT) on the sensing area, PDMS polymer cavity is configured in the centre of CPW transmission line. The electromagnetic interaction with the varying dielectric constant of Glucose:DI water solution results shift in S11 parameter, which is closely observed to use as the source of sensing. CPW based glucose sensor is experimentally measured for S11 parameter using VNA, with varying glucose concentration range from 0 mg/ml (only DI water) to 4 mg/ml with the interval of 1 mg/ml. The measured results showed good sensitivity of 108.4 MHz/mg/ml and high accuracy with good linear regression coefficient of 0.9979.
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    Efficient Cycle Frequency Acquisition of a Cyclostationary Signal with the FACA Method
    (Společnost pro radioelektronické inženýrství, 2019-06) Hu, Yi; Yu, Baoguo; Deng, Zhixin; He, Guodong; Zhou, Haijun
    The cycle frequencies of a cyclostationary signal can be used for the signal identification and classification, separation of the overlapped signals in cycle domain, and so on. Efficient cycle frequency acquisition depends on the fast measurement of cyclic autocorrelation function (CAF) or spectral correlation function (SCF) of the signal. Presently the relative efficient CAF and SCF measuring methods mainly include the cyclic correlogram, the well-known fast Fourier transform accumulation method (FAM), and so on. Motivated by these methods, a new efficient cycle frequency acquisition method which integrates the fast Fourier transform (FFT) algorithm with the autocorrelated cyclic autocorrelation function, named FACA, is presented. With the presented method, we can acquire the cycle frequencies of a cyclostationary signal more efficiently with a given level of reliability. Meanwhile, by enlarging the FFT window width of the FACA method we can get the same cycle frequency resolution as the benchmarked method FAM, but the computation cost still can be spared at this case.