Recent Submissions

Now showing 1 - 5 of 10
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    Performance Analysis and Comparison of Anomaly-based Intrusion Detection in Vehicular Ad hoc Networks
    (Společnost pro radioelektronické inženýrství, 2020-12) Shams, Erfan A.; Ulusoy, Ali Hakan; Rizaner, Ahmet
    Security and safety applications of Vehicular Ad hoc Networks (VANETs) are developed to improve the traffic flow. While safety applications in VANETs provide warnings and information for the vehicle and other units in the area, malicious behaviors can render this very purpose meaningless. Intrusion Detection Systems (IDSs) are key features for identifying the presence of faulty or malicious behaviors. Support Vector Machine (SVM) is an efficient tool for anomaly detection and it can be employed for intrusion detection based on the metrics of a known attack or normal behavior. Dropping and or delaying network packets are two of the most common variants among other methods in Denial of Service (DoS) attacks. Hence an IDS which can detect both variants can detect similar types of DoS attacks. The result of the study is obtained by designing and implementing an SVM detection module into computer-generated simulation, which depicts a successful outcome in detection of mentioned DoS attack variants.
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    Estimating the Characteristics of the Forward Voltage Gain Scattering Parameter of Indoor Power Line Channel Using Only Input Port Measurement
    (Společnost pro radioelektronické inženýrství, 2020-12) Chatterjee, Sujit; Baishya, Rubi; Tiru, Banty
    Estimation of the characteristics of power line channel is a pre-requisite for successful implementation of any power line communication system. This paper presents a method to estimate the forward voltage gain scattering parameters (S21) of an indoor power line using only the input port reflection coefficient (S11). The measured input parameter with one/two load placed at the output suffices to estimate the S21 as far as frequency selectivity is concerned. The positions of notches can be estimated within a limit of error with positive and at times high correlation between the experimental and evaluated S21 parameters. The method is validated for a number of practical networks, and also for random channels with different types of loads and cables found in the papers. The procedure can be incorporated in estimating the channel for mitigating the related problems.
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    Full Duplex Relaying in Non Orthogonal Multiple Access System with Advanced Successive Interference Cancellation
    (Společnost pro radioelektronické inženýrství, 2020-12) Hussain, Qaiser; Sohaib, Sarmad
    This paper describes a full-duplex (FD) cooperative non orthogonal multiple access (NOMA) system with dedicated relay under residual self-interference (RSI). An advanced successive interference cancellation (ASIC) technique is proposed in the FD cooperative NOMA system as an alternate of successive interference cancellation (SIC) scheme. The ASIC scheme maps the received signal into subgroups and by applying conventional SIC scheme on each subgroup results in separation of signals. The approximated analytical expressions of outage probability and ergodic sum rate for proposed ASIC based FD DF cooperative NOMA system are derived and the system throughput is analyzed. Finally, according to the results, our proposed ASIC based FD DF cooperative NOMA system shows better outage performance and higher ergodic sum rate as compared to conventional SIC based FD DF cooperative NOMA system.
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    The Influence of the Bitrate Level on the Subjective Sound Quality Perception of the Concatenated Non-Entropic Audio Coding Algorithms in the Digital Broadcasting Chain
    (Společnost pro radioelektronické inženýrství, 2020-12) Zyka, Karel
    Digital Audio Broadcasting (DAB) and all similar systems for digital radio and television broadcasting are inevitably associated with lossy psychoacoustic audio compression. The coding algorithms are continuously being improved. To achieve high sound quality a lower bitrate, required by the broadcasters, is now sufficient. This paper compares the relevant digital audio codecs: MPEG 2 and AAC in three profiles (AAC LC, HE-AAC v1 and HE-AAC v2). The well-known MP3 format is also added for a better comparison. A brief description of the basic functional principles of the codecs is followed by a comparison of their efficiency keeping in mind the subjectively comparable sound quality. The main contribution of this paper is the verification of the relationship of the bitrate level and sound quality in broadcasting environment and the finding out the influence of other, often more significant factors, such as the primary quality of the input recordings and the concatenation of non-entropic coding, on the subjective perception in the digital broadcasting chain. These findings are supported by the results of a unique research analysis providing an insight into which specific audio encoding configurations are used for DAB+ radio broadcasting in practice, in Europe as a whole and in individual European countries.
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    Compact Ultra Wide-Band and Tri-Band Antenna for Portable Device
    (Společnost pro radioelektronické inženýrství, 2020-12) Ghaffar, Adnan; Awan, Wahaj Abbas; Zaidi, Abir; Hussain, Niamat; Rizvi, Syed Muhammad; Li, Xue Jun
    A compact ultra-wideband (UWB) and triband patch antenna with the partial ground plane is presented in this paper. Initially, the antenna is designed for UWB applications, operating at the UWB portion of the spectrum ranging from 3.1 GHz to 10.6 GHz, then it is modified to operate at three distinct frequencies of 2.45 GHz, 5 GHz, and 10.2 GHz. The proposed antenna is inspired by a classic rectangular patch antenna in which slots, stubs, and defected ground structure (DGS) were introduced to increase its operational bandwidth. Good results in terms of return loss are found in all resonant frequencies as well as for the single wideband. In addition, the proposed antenna has been compared with related works in the literature, to highlight its potential for future UWB and multiband portable devices.