shadow fading
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Electronics ◽  
2021 ◽  
Vol 10 (24) ◽  
pp. 3164
Author(s):  
Manjit Kaur ◽  
Deepak Prashar ◽  
Mamoon Rashid ◽  
Sultan S. Alshamrani ◽  
Ahmed Saeed AlGhamdi

In the last decades, flying ad-hoc networks (FANET) have provided unique features in the field of unmanned aerial vehicles (UAVs). This work intends to propose an efficient algorithm for secure load balancing in FANET. It is performed with the combination of the firefly algorithm and radio propagation model. To provide the optimal path and to improve the data communication of different nodes, two-ray and shadow fading models are used, which secured the multiple UAVs in some high-level applications. The performance analysis of the proposed efficient optimization technique is compared in terms of packet loss, throughput, end-to-end delay, and routing overhead. Simulation results showed that the secure firefly algorithm and radio propagation models demonstrated the least packet loss, maximum throughput, least delay, and least overhead compared with other existing techniques and models.


Author(s):  
Ahmad Hakimi Bin Ahmad Sa'ahiry ◽  
Abdul Halim Ismail ◽  
Latifah Munirah Kamaruddin ◽  
Mohd Sani Mohamad Hashim ◽  
Muhamad Safwan Muhamad Azmi ◽  
...  

Indoor positioning system has been an essential work to substitute the Global Positioning System (GPS). GPS utilizing Global Navigation Satellite Systems (GNSS) cannot provide an accurate positioning in the indoor due to the multipath effect and shadow fading. Fingerprinting method with Wi-Fi technology is a promising system to solve this issue. However, there are several problems with the fingerprinting method. The fingerprinting database collected has different sample sizes where the previous researcher does not indicate any standard for the sample size to be used. In this paper, the effect of the sample sizes in fingerprinting database for Wi-Fi technology has been discussed deeply. The statistical analyzation for different sample sizes has been analyzed. Furthermore, two methods which are K- Nearest Neighbor (KNN) and Deep Neural Network (DNN) are being used to examine the effect of the sample sizes in term of accuracy and distance error. The discussion in this paper will contribute to the better sample size selection depending on the method taken by the user. The result shows that sample sizes are an important metrics in developing the indoor positioning system as it effects the result of the location estimation.


Sensors ◽  
2021 ◽  
Vol 21 (19) ◽  
pp. 6534
Author(s):  
Mehdi Zeinali ◽  
John S. Thompson

In the last few years, Low-Power Wide-Area Network (LPWAN) technologies have been proposed for Machine-Type Communications (MTC). In this paper, we evaluate wireless relay technologies that can improve LPWAN coverage for smart meter communication applications. We provide a realistic coverage analysis using a realistic correlated shadow-fading map and path-loss calculation for the environment. Our analysis shows significant reductions in the number of MTC devices in outage by deploying either small cells or Device-to-Device (D2D) communications. In addition, we analyzed the energy consumption of the MTC devices for different data packet sizes and Maximum Coupling Loss (MCL) values. Finally, we study how compression techniques can extend the battery lifetime of MTC devices.


Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 1162
Author(s):  
Sangwoo Lee ◽  
Ilmu Byun ◽  
Sungjin Kim ◽  
Sunwoo Kim

This paper presents a theoretical analysis of mobility detection in connectivity-based localization, which exploits connectivity information as range measurements to anchors at a known location, to investigate how well and how precise mobility can be detected with connectivity in short-range networks. We derive mobility detection, miss detection, and false alarm probabilities in terms of a mobility detection threshold, defined as the minimum distance to detect the mobility, under the shadow fading channel and arbitrary mobility models to take into account practical and general scenarios. Based on the derivations, we address the threshold determination with the criteria in the sense of the minimum average error from miss detection and false alarm. Numerical and simulation evaluations are performed to verify our theoretical derivations, to show that increasing anchor numbers can improve the mobility detection probability with a smaller detection threshold, and that the probabilities are bounded by the weights of miss detection and false alarm. This work is the first attempt at addressing the performance of mobility detection using connectivity, and it can be utilized as a baseline for connectivity-based mobility tracking.


2020 ◽  
Vol 10 (18) ◽  
pp. 6397
Author(s):  
Jing Ke ◽  
Xiaochun Lu ◽  
Xue Wang ◽  
Xiaofei Chen ◽  
Sheng Tang

This work investigated concatenated coding schemes for Global Navigation Satellite System (GNSS) signals in order to increase their error correction capability in urban environments. In particular, a serial concatenated code that combines an outer Reed–Solomon (RS) code with an inner low-density parity-check (LDPC) code was designed, and the performance was investigated over the land mobile satellite (LMS) channel for characterizing multipath and shadow fading in urban environments. The performance of the proposed concatenated coding scheme was compared to that of a B-CNAV1 message, in which two interleaved 64-ary LDPC codes were employed. The simulation results demonstrate that the proposed concatenated code can obtain a similar error correction performance to the two interleaved 64-ary LDPC codes in both the additive white Gaussian noise (AWGN) and LMS channels at a lower complexity level.


Author(s):  
Souparnika Subhash Jadhav ◽  
Nagesh K. N ◽  
Ravi Chaurasia

<p><span>Over some few decades, the communication distance and connectivity at wireless sensor network (WSN) has got noticeable attention from the researchers. In general, the communication process in WSN ad-hoc occurs without some wired infrastructure and, the communication process done through a ‘single-hop’ transmission, where the intermediate nodes called as relay nodes are used in long distance communication and the nodes are capable to transmit and receive the data packets. In this paper, we presented a computational analysis of communication distance in WSN in the presence of fading effects such as nakagami-m fading and lognormal fading. An extensive investigation at both nakagami-m fading and lognormal fading is carried out to provide optimize communication in ad-hoc WSN. In addition, individual wireless nodes have the similar range of communication, is assumed to get the precise communication distance and coverage area in a WSN, where it is required to get mean communication distance. In result analysis section, several validation parameters such as transmitted power, attenuation constant and different number of fading factor is considered to provide proper analytical view. </span></p>


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