2020/4

Browse

Now showing 1 - 5 of 10

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.
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.
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.
An Independently Biased 3-stacked GaN HEMT Power Amplifier for Next-Generation Wireless Communication Systems
(Společnost pro radioelektronické inženýrství, 2020-12) Duy Manh Luong; Xuan Nam Tran
In this paper, a design of 3-stacked GaN highelectron-mobility transistor radio-frequency power amplifier employing an independently biased technique is presented to meet stringent requirements of next-generation wireless communication systems. The ability of independently adjusting operation conditions for each transistor of the proposed amplifier makes it possible to operate not only for high efficiency, high linearity but also for both improved efficiency and linearity. Efficiency can be optimized through varying drain bias voltages. Linearity, however, can be optimized independently through varying gate bias voltages. Importantly, both efficiency and linearity can be optimized simultaneously by making a compromise between drain and gate bias voltages. In contrast to conventional methods, the proposed configuration still ensures a compact size for design of the power amplifier. This can be feasible because the proposed solution is introduced in the device level using a MMIC technology. These superior advantages make the proposed PA a promising candidate for using in transceiver of the next-generation wireless communications systems.
Design of Miniaturized SIW Filter Loaded with Open-Loop Resonators and Its Application to Diplexer
(Společnost pro radioelektronické inženýrství, 2020-12) Barik, Rusan Kumar; Cheng, Qingsha S.; Pradhan, Nrusingha Charan; Karthikeyan, Sholampettai Submaranian
This paper presents a novel design of miniaturized substrate-integrated waveguide (SIW) filter loaded with a pair of unit-cell resonators. Two identical open-loop resonators are connected face-to-face to form a unit-cell. A pair of unit-cells is engraved on the surface of the SIW to develop an evanescent-mode bandpass filter. The proposed unit-cells behave as an electric-dipole and produce a passband smaller than the waveguide frequency. This reduction in resonant frequency allows us to achieve size miniaturization. An equivalent electrical-circuit model is developed and investigate for characterization of passband and transmission-zero. This filter structure is then employed to develop a SIW planar diplexer. Two SIW filter structures loaded with unit-cells are excited with a T-shaped feed line to achieve lower and upper channels of the diplexer. To demonstrate the analysis, both SIW filter and diplexer loaded with open-loop resonators are implemented and fabricated. The proposed SIW filter and diplexer prototypes exhibit size miniaturization, low insertion-loss and high-selectivity due to evanescent-mode transmission and sub-wavelength resonators. The measurement responses are very similar to the simulation responses.

Browse

Recent Submissions