2019/2

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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.
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.
Fast Convergence Algorithms for Coherence Optimization of Rank-1 Grassmannian Codebooks
(Společnost pro radioelektronické inženýrství, 2019-06) Akram, Faisal; Rashid, Imran; Ghafoor, Abdul; Siddiqui, Adil Masood
Best Complex Antipodal Spherical Codes (BCASC) and Coherence Based Grassmannian Codebooks (CBGC) are state of the art algorithms to produce minimal coherence codebooks, however have high running time (relatively more in BCASC search than CBGC algorithm) which restricts their wider application. BCASC and CBGC algorithms are modified in a novel way by incorporating additional parameters adapted to three categories of codebooknovercompleteness to check stagnance of optimization and divergent behaviour to achieve faster convergence. The proposed algorithms are compared with BCASC and CBGC algorithms to achieve similar coherence results in much less time.
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.
Spectrum Sensing Based on Higher Order Cumulants and Kurtosis Statistics Tests in Cognitive Radio
(Společnost pro radioelektronické inženýrství, 2019-06) Bozovic, Rade; Simic, Mirjana
In this paper, new algorithms for spectrum sensing in cognitive radio based on higher order cumulants and kurtosis are proposed. The cumulants represent statistical signal processing based on pattern recognition for signals of different structure, and has low implementation complexity. Kurtosis statistics are a well-known technique for testing the Gaussianity feature of the signals. Under the assumption that a detected signal can be modelled according to an autoregressive model, noise variance is estimated from that noisy signal. The simulation results show that spectrum sensing algorithms based on the estimated normalised values of joint higher order cumulants (of fourth and sixth orders) and kurtosis are reliable for a wide range of signal-to-noise ratio environments. In order to improve performances of the spectrum sensing, the combination of these statistics tests into unique one statistic test is proposed. Simulation results have verified improvement of the performances.

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