The rapid growing data traffic brings more and more pressure to the wireless networks,which is predicted to increase by over 10,000 times in the next 20 ***,currently,there is still large number of population without ...
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The rapid growing data traffic brings more and more pressure to the wireless networks,which is predicted to increase by over 10,000 times in the next 20 ***,currently,there is still large number of population without coverage of mobile *** addition
A multiuser Ultra Wide Band (UWB) channel suffers seriously from realistic impairments. Among this, multipath fading and interferences, such as Multiple Access Interference (MAI) and Inter Symbol Interference (ISI), t...
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A multiuser Ultra Wide Band (UWB) channel suffers seriously from realistic impairments. Among this, multipath fading and interferences, such as Multiple Access Interference (MAI) and Inter Symbol Interference (ISI), that significantly degrade the system performance. In this paper, a polar coding technique, originally developed by Arikan, is suggested to enhance the BER performance of indoor UWB based Orthogonal Frequency Division Multiplexing (OFDM) communications. Moreover, Interleave Division Multiple Access (IDMA) scheme has been considered for multiuser detection depending on the turbo type Chip-By-Chip (CBC) iterative detection strategy. Three different models as Symmetric Alpha Stable (SαS), Laplace model and Gaussian Mixture Model (GMM), have been introduced for approximating the interferences which are more realistic for UWB system. The performance of the proposed Polar-coded IDMA OFDM-based UWB system is investigated under UWB channel models proposed by IEEE 802.15.3a working group and compared with Low Density Parity Check (LDPC)-coded IDMA OFDM-based UWB system in terms of BER performance and complexity under the studied noise models. Simulation results show that the complexity of the proposed polar-coded system is much lower than LDPC-coded system with minor performance degradation. Furthermore, the proposed polar-coded system is robust against noise and interferences in UWB indoor environment and gains a significant performance improvement by about 5 dB compared with un-coded IDMA-OFDM-UWB system under the studied noise models.
Vehicle-to-everything (V2X) communication in the mmWave band is one way to achieve high data-rates for applications like infotainment, cooperative perception, and augmented reality assisted driving etc. MmWave communi...
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Flywheels are one of the promising energy storage devices for stabilizing the power quality of reusable energy, owing to their fast response time and high cycle lifetime. However, it can be catastrophic when they fail...
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Flywheels are one of the promising energy storage devices for stabilizing the power quality of reusable energy, owing to their fast response time and high cycle lifetime. However, it can be catastrophic when they fail, because they store kinetic energy that can be released in a short amount of time. Data-driven monitoring techniques have been proposed to solve fault detection tasks in several types of rotation machinery with ball bearings. In contrast to traditional approaches using human-engineered features that require a high level of expertise, a data-driven approach requires no such prior knowledge. However, flywheels differ from typical rotation machinery because they use a magnetic or pivot bearing, and it is unclear whether a data-driven method can be used to detect a fault. In the present study, the effectiveness of a data-driven fault detection system for flywheels that use pivot bearings is evaluated. A flywheel fault progresses in several stages, and vibration data were collected for a flywheel running at each of those stages. A convolutional neural network (CNN) was exploited to detect a fault of the flywheel and identify a mode of the fault. Experimental comparisons conducted using vibration signals from an actual flywheel demonstrated that faulty operational state observed at an end of the flywheel’s life can be detected with high accuracy using a data-driven method.
—Conventional multiuser detection techniques either require a large number of antennas at the receiver for a desired performance, or they are too complex for practical implementation. Moreover, many of these techniqu...
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In this paper, we study an energy efficient cluster-based multi-hop routing (ECMR) protocol to prolong the network lifetime and improve the data transmission efficiency in wireless sensor networks. The residual energy...
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Conventional interference suppression techniques based on scalar antenna array may not be effective, when the satellite and interference signals have similar directions of arrival. In this paper, a power inversion (PI...
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ISBN:
(数字)9781728109626
ISBN:
(纸本)9781728109633
Conventional interference suppression techniques based on scalar antenna array may not be effective, when the satellite and interference signals have similar directions of arrival. In this paper, a power inversion (PI) algorithm with a novel constraint is proposed which is applied to electromagnetic vector sensor (EMVS) arrays and improve the performance of the standard PI algorithm. Interference with different polarization parameters than the satellite signal can be suppressed even when they have the same incident direction. A fast implement scheme is designed for the proposed algorithm and is effective for the Beidou satellite system public service signal.
The implementation of an accurate face recognition system in a hardware device is a very important aspect of various security applications. In a security system, any type of password is used to access private and conf...
The implementation of an accurate face recognition system in a hardware device is a very important aspect of various security applications. In a security system, any type of password is used to access private and confidential data, some are hard to remember and can be stolen or guessed, misplaced, forgotten, purloined or duplicated, or become corrupted and unreadable. While there have been significant improvements in the algorithms with increasing recognition accuracy, only a few types of research were conducted on implementing these face recognitions in hardware devices. Door access control systems based on face recognition is geared towards simplifying much-difficult face recognition problems in uncontrolled environments. This report comprised mainly of three sub-phases: face detection, face recognition, and automatic door access control. The face is detected by using the Viola-Jones method and face recognition is implemented by using the Principal Component Analysis (PCA). If a face is recognized, it is known, else it is unknown. The door will open automatically for the known person due to the command of the microcontroller (Atmega328P) received from the MATLAB program. On the other hand, the alarm will ring for an unknown person.
The study has outlined the different correction codes based optical wireless communication channel and security management in free space optics communication systems. The used codes that are namely forward error corre...
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