scholarly journals Ultrawideband combined vibrator-slot Clavin type radiator

2020 ◽  
Keyword(s):  
Communication Networks ◽  
Information Transfer ◽  
Ultra Wideband ◽  
Wireless Communication Networks ◽  
Electromagnetic Pulses ◽  
Time Frequency ◽  
Wide Range ◽  
Narrow Frequency Range ◽  
Magnetic Type ◽  
Multiparameter Optimization

Background. Ultrawideband communication is a promising way of transmitting information that uses short electromagnetic pulses. It has great potential due to higher bandwidth than other methods of information transfer. This allows you to create ultra-fast wireless communication networks. But the implementation of ultra-wideband communication requires the use of compact and efficient pulsed emitters. Object. Create a compact pulsed combined antenna of electric and magnetic type, ultra-wideband analogue of the Clavin radiator, in which the necessary characteristics are provided by a strong interaction of its components. It is also necessary to analyze the directional, frequency and time characteristics of such a radiator. Methods: The numerical method of finite differences in time domain (FDTD) is used for the final calculation and optimization of the radiator. The initial design is calculated in a narrow frequency range by the method of electric and magnetomotive forces. Results. The multiparameter optimization of the antenna is carried out in order to find the optimal interaction between the electric and magnetic emitter while providing the required directional and frequency characteristics. The radiation patterns in the H and E planes for a number of frequencies are obtained, and the time dependences of the radiated field in these planes are constructed. Conclusions.The analog of the Clavin radiator can concentrate the energy of the radiation in a given direction and provide a wide range of operating frequencies, which in this implementation of antenna reaches 1 GHz. It should be noted the compactness of this structure and the presence of a number of geometric parameters, the change of which can improve the time parameters of the radiated field. The ultra-wideband combined vibrator-slot structure has several directions for further optimization of time, frequency and directional characteristics in accordance with the requirements of specific applications.

scholarly journals Intelligent reflected surfaces assisted code domain non-orthogonal multiple access scheme

2021 ◽  
Vol 72 (5) ◽  
pp. 343-347
Author(s):  
Aasheesh Shukla
Keyword(s):  
Communication Networks ◽  
Information Transfer ◽  
Multiple Access ◽  
Wireless Communication Networks ◽  
Radio Waves ◽  
Reflection And Refraction ◽  
Access Scheme ◽  
Code Domain ◽  
Efficient Code ◽  
Phase Amplitude

Abstract The propagation medium plays a crucial role in any wireless communication networks, the channel between the transmitter and the receiver, deteriorate the quality of the received signal due to the uncontrollable interactions such as scattering, reflection, and refraction in the channel with the surrounding objects. To overcome this challenge, the recent advent of recongurable intelligent surfaces can be helpful, in which the network operators can control the radio waves, eg, the phase, amplitude, frequency, and even polarization, of the impinging signals without the need of complex decoding, encoding, and radio frequency processing operations. On the other hand, few research papers reported an efficient code domain non orthogonal multiple access (NOMA) such as Interleave division multiple access (IDMA) system for wireless information transfer. Persuaded by the capability of this arising RIS technology, the present article is aimed to provide the modified framework of IDMA (code-domain NOMA) communication system based on RIS technology. Simulation results demonstrate that the proposed system achieves better SNR performance than the conventional IDMA framework.

scholarly journals Cooperative non-orthogonal multiple access for wireless communication networks by exploiting the EXIT chart analysis

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Zeyad Elsaraf ◽  
Abbas Ahmed ◽  
Faheem Ahmad Khan ◽  
Qasim Zeeshan Ahmed
Keyword(s):  
Communication Networks ◽  
Interference Cancellation ◽  
Communication Systems ◽  
Information Transfer ◽  
Multiple Access ◽  
Salient Feature ◽  
Convolutional Codes ◽  
Spectrum Efficiency ◽  
Exit Chart ◽  
Time Frequency

AbstractIn the next generation of mobile communication networks, unprecedented challenges are required to be met, such as much higher data rates and spectrum efficiency, lower latency, and massive connectivity. Non-orthogonal multiple access (NOMA) has recently been proposed as a promising technology to achieve much superior spectral efficiency compared to conventional orthogonal multiple access techniques employed in present communication systems. A salient feature of NOMA is its use of successive interference cancellation (SIC) to decode users’ information when multiple users are allowed to transmit in same time/frequency/code domain. In this paper, we aim to exploit an aspect of SIC, namely the availability of other users’ data to realize a cooperative NOMA system. EXtrinsic information transfer (EXIT) charts are utilized to examine the performance of proposed system in terms of user fairness while employing IRregular convolutional codes (IRCC)s. The EXIT chart using IRCC evaluates the convergence analysis for the proposed system. Further, to evaluate the system performances in cooperative NOMA system, we have derived the expressions for the achievable rates which are obtained independently and utilized them in evaluating the experimental data for the proposed NOMA model.

VerSA

2021 ◽  
Vol 15 (3) ◽  
pp. 65-82
Author(s):  
Oladayo Olufemi Olakanmi ◽  
Kehinde Oluwasesan Odeyemi
Keyword(s):  
Communication Networks ◽  
Wireless Communication Networks ◽  
Security Risks ◽  
Batch Verification ◽  
Wide Range ◽  
Augmented Reality Technology ◽  
Data Grouping ◽  
Aggregation Scheme ◽  
Iot Devices ◽  
The Internet Of Things

The advent of the internet of things (IoT) and augmented reality technology not only introduces a wide range of security risks and challenges but also increases traffic on the existing wireless communication networks. This is due to the enormity of the traffics generated by the connected IoT devices whose number keeps increasing. Therefore, any IoT network requires an effective security solution capable of securing data and minimizing traffic on the IoT networks. To address these, the authors propose a practicable secure data aggregation scheme, VerSA, based on data grouping aggregation, batch verification through the aggregated signature ratios, and symmetric encryption with a pairing free key distribution. The scheme is capable of grouping and aggregating sub-network data into homogeneous and heterogeneous groups, detecting and filtering injected false data. The results show that the proposed scheme is not only secure against IoT related attacks but also has the lowest computational and communication overheads compared to the recent state-of-the-art schemes.

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