Arabic Vowels Acoustic Characterization

International audienceA sentence is constructed using basic word units. Each word is composed of syllables and each syllable being composed of phonemes, which in turn, can be classified as vowels or consonants. Vowels may occupy the center or nucleus of a syllable, as opposed to consonants, which occur in marginal positions in a syllable (onsets and codas).Vowels appear early in speech development and are central to understanding the acoustic properties of speech. The aim of this work is to enrich the automatic speech recognition system, by the classification of Arabic vowels based on normalized energy in the formant frequency bands

A Survey on RF Energy Harvesting-RFEH- in WSNs

International audienceLately, WSNs have attracted lot of attention due to their ubiquitous nature and their varied utilization in IOT, Cyber Physical Systems, and other emerging fields. The restricted energy related to wireless sensor networks is a considerable bottleneck of these networks. To surpass this serious limitation, the design and development of high performance and efficient energy harvesting systems for WSN environments are being inspected. We present a comprehensive taxonomy of the different energy harvesting sources that can be adopted by wireless sensor networks. We discuss also many freshly suggested energy prediction models that have the ability to boost the energy harvested in wireless sensor networks. To finish, we identify some of the challenges that still need to be addressed to develop cost-effective, efficient, and reliable energy harvesting systems for the WSN environment

Smart monitoring information system based on RF 433 Mhz (SMIS)

Many research works are devoted to the design of remote control systems of objects. Remote monitoring is among the technologies of data acquisition on a remote object and its characteristics without physical contact with it. These data can be collected by acoustic waves, the distribution of forces and electromagnetic energy to process them to locate the object and its characteristics. This paper presents a smart monitoring information system based on RF 433MHz, Arduinonano and arduinouno named SMIS

ESTIMATION DU CANAL OFDM RADIO MOBILE A FORTE MOBILITE PAR UNE INTERPOLATION POLYNOMIALE DANS LE DOMAINE TEMPOREL

Ce travail s'inscrit dans le cadre des systèmes radio mobiles basés sur la modulation multi-porteuse OFDM.  L'objectif est de proposer une technique permettant l’estimation efficace du canal dynamique pour les  récepteurs OFDM à grande mobilité. Dans cet article, nous avons développé une méthode d’estimation des variations temporelles des gains complexes pour un canal dynamique à effet Doppler. Cette méthode est basée sur les valeurs moyennes des gains complexes qui sont estimées par un estimateur LS sur K blocs OFDM consécutifs, et une interpolation polynomiale dans le domaine temporel des variations du canal. La technique présentée, se base sur le fait que la valeur moyenne d’un processus de Rayleigh est extrêmement proche de la valeur centrale d’un bloc OFDM pour les récepteurs à vitesses élevées réalistes qui peuvent atteindre 300 km/h.

Energy distribution in formant bands for arabic vowels

The acoustic cues play a major role in speech segmentation phase; the extraction of these indexes facilitates the characterization of the speech signal. In this work, we aim to study Arabic vowels (/a/, /a:/, /i/, /i:/, /u/ and /u:/), especially the long ones. We are interested in characterizing this type of vowels in terms of time, frequency and energy. The cues extracted and analyzed in this work are: segment length, voicing degree and formants values

Performance Improvement for Vehicular Communications Using Alamouti Scheme with High Mobility, Journal of Telecommunications and Information Technology, 2020, nr 3

The IEEE 802.11p standard is the basic protocol for wireless access in a vehicular environment (WAVE), providing high throughput for multimedia and high quality for vehicular transmissions. However, IEEE 802.11p fails to offer any multi-antenna approaches. In this paper, a multipleinput single-output (MISO) implementation with orthogonal frequency division multiplexing (OFDM), aiming to improve the performance of IEEE 802.11p, is proposed. The authors investigate the impact of time-varying channel on the performance of Alamouti space-time block codes (STBC) in OFDM systems. The Alamouti STBC approach shows good performance in slow time-varying environments, while its Alamouti space frequency block codes (SFBC) counterpart performs better over fast time-varying environments. An adaptive switching scheme is proposed to select appropriate spaceblock coding (STBC or SFBC) in vehicular channels with high mobility levels. It is shown that the proposed adaptive scheme provides better performance compared with traditional spaceblock code

MG-leach: an enhanced leach protocol for wireless sensor network

A wireless sensor network is made up of a large number of small sensor nodes with limited energy resources, which is a real problem for this network. In this article, we will study the ingestion of node energy in these networks at the routing level. In addition, we are modifying one of the most popular routing algorithms for data communication in the WSN: LEACH (Adaptive Hierarchy with Low Power Consumption). The modified version of the LEACH base version "MG_LEACH" uses an intermediate cluster header to transmit data, extend the network lifetime and send more data than the original protocol. Our proposed algorithm is simulated using MATLAB to verify the effectiveness of improving the lifetime of this network. The results of the simulation confirmed that the system was working better than the LEACH basic system and that the network life had been improved. 

A novel coplanar slot antenna structure for wireless applications

This paper presents a new compact broadband coplanar slot antenna for multiple wireless communication applications which include WIMAX, RFID, WLAN and ISM bands. The antenna structure is based on the CPW-fed combined with a slot technique and a modified geometry antenna in order to enlarge the bandwidth. The antenna parameters have been investigated and optimized by using Momentum software integrated into ADS” Advanced Design System” from Agilent Technologies with a comparison of the results using another simulator CST Microwave Studio. The measured input impedance bandwidth, ranging from 2.15GHz to 4.4GHz, is obtained with a return loss less than - 10dB, corresponding to 66.7% at 3.27GHz as a center frequency. The design considerations for achieving broadband antenna and both experimental, simulated results are presented

A new compact printed antenna structure for multiple wideband applications

This paper presents the design of a new compact antenna structure for multiple incorporating operation service. The proposed antenna is suitable to operate at three different frequency bands, (1.77GHz-2.67GHz), (3.1GHz- 4.58GHz), and (5.5GHz-6.5GHz) with a return loss less than -10dB. The antenna structure includes a CPW fed line, the technique used to enlarge the frequency bands is the slots technique and in the same time we have developed a new antenna structure which operates in various wireless communication applications. The antenna parameters have been investigated and optimized by using CST Microwave Studio. To validate the CST Microwave Studio results before the antenna achievement, we have conducted another study by using ADS. The final circuit was achieved, measured and validated. Experimental results show that the proposed antenna with compact size of 42*32.7 mm2 has good radiation characteristics and operating in specific microwave applications ISM band, WLAN, WIFI, WIMAX and RFID