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Research ArticleOpen accessEvery word in the titlePerformance Analysis of Orthogonal Frequency Division Multiplexing Based Bidirectional Relay Network in the Presence of Phase NoiseV. N. Senthil Kumaran, S. Rajkumar, S. J. ThiruvengadamIn this study, the performance of OFDM based bidirectional relay network which employs Physical Layer Network Coding (PLNC) is analyzed in the presence of phase noise. The bidirectional relay network is assumed to consist of two sources and a relay, where each node has a single antenna and operates in half duplex mode. The PLNC based OFDM system transmits high … …American Journal of Applied Sciences, Vol. 10, Issue 11 · 9 Sep 2013 · 6,639 accessesView PDFCite
Research ArticleOpen accessEvery word in the titleAN EFFICIENT POWER REDUCTION TECHNIQUE IN ORTHOGONAL FREQUENCY DIVISION MULTIPLEXING SYSTEM USING TONE RESERVATIONV. Nandalal, S. SophiaIn a basic communication system, the data’s are modulated onto a single carrier frequency. The available bandwidth is then totally occupied by each symbol. This kind of system can lead to Inter-Symbol-Interference (ISI) in case of frequency selective fading. The basic idea of Orthogonal Frequency Division Multiplexing (OFDM) is to divide the available spectrum into several orthogonal sub channels so … …Journal of Computer Science, Vol. 9, Issue 9 · 6 Aug 2013 · 6,471 accessesView PDFCite
Research ArticleOpen accessEvery word in the titleModeling of Fundamental Frequency Contours for Thai Dialects with Large Speech DatabaseSuphattharachai ChomphanIn four core regions of Thailand, there are four main dialects including central, north, northeast and south dialects. The prosody is significantly unique for each dialect. One important factor determining the prosody is the fundamental frequency. As a result, modeling of Fundamental frequency (F0) contour is very important for the natural speech processing. Even though there are many modeling techniques … …American Journal of Applied Sciences, Vol. 9, Issue 12 · 20 Dec 2012 · 7,341 accessesView PDFCite
Research ArticleOpen accessEvery word in the titleEffects of Noises on Fujisaki’s Model of Fundamental Frequency Contours for Thai DialectsSuphattharachai Chomphan, Chutarat ChompunthProblem statement: Modeling of fundamental frequency (F0) contour plays an important role on the natural speech processing, since F0 is an important speech feature defining the human speech prosody. In Thai, there are four main dialects spoken by Thai people residing in four core region including central, north, northeast and south regions. Environmental noises are also plays an important role … …American Journal of Applied Sciences, Vol. 9, Issue 10 · 25 Aug 2012 · 6,981 accessesView PDFCite
Research ArticleOpen accessEvery word in the titleAnalytical Study of Fujisaki’s Model of Fundamental Frequency Contour for Thai TonesSuphattharachai Chomphan, Chutarat ChompunthProblem statement: Tone of a tonal language is an important feature of a prosodic syllable to identify the meanings of that syllable or that part of word. Ii is very crucial to model the feature related to tone of speech to achieve the most naturalness in speech communication. Approach: The study presents an approach to analyze the model parameters of … …American Journal of Applied Sciences, Vol. 9, Issue 10 · 16 Aug 2012 · 6,991 accessesView PDFCite
Research ArticleOpen accessEvery word in the titleEffects of Noises on Fundamental Frequency Extraction Using Cepstral Analysis for Thai DialectsSuphattharachai ChomphanProblem statement: The fundamental frequency (F0) of the human speech corresponds to the vibration frequency of the human vocal chords. To extract the F0 from a speech utterance, one approach is based on the Cepstral analysis. In Thai, there are four main dialects spoken by Thai people residing in four core region including central, north, northeast and south regions. Environmental … …American Journal of Applied Sciences, Vol. 9, Issue 9 · 28 Jul 2012 · 6,908 accessesView PDFCite
Research ArticleOpen accessEvery word in the titleFujisaki’s Model of Thai’s Fundamental Frequency Contours with Environmental NoisesSuphattharachai Chomphan, Chutarat ChompunthProblem statement: An important human speech feature is the fundamental frequency (F0) contour which represents the speech prosody. It indicates the naturalness and intelligibility of the speech. Modeling of fundamental frequency contour was an essential procedure in the natural speech processing. In speech communication, environmental noise plays an essential role in damaging the digital communication quality. The study of effects … …American Journal of Applied Sciences, Vol. 9, Issue 8 · 28 Jun 2012 · 7,284 accessesView PDFCite
Research ArticleOpen accessEvery word in the titleEffects of Environmental Noises on Fundamental Frequency Contours of Thai DialectsSuphattharachai Chomphan, Chutarat ChompunthProblem statement: Fundamental Frequency (F0) is an important speech feature defining the human speech prosody. It is the resultant of the vibration of human’s vocal chords in speech production. In Thai, there are four main dialects spoken by Thai people residing in four core region including central, north, northeast and south regions. Environmental noises are also playing an important role … …American Journal of Applied Sciences, Vol. 9, Issue 5 · 9 Mar 2012 · 7,031 accessesView PDFCite
Research ArticleOpen accessEvery word in the titleMultiple Input Multiple Output System with Space Time Block Coding and Orthogonal Frequency Division MultiplexingP. Ramesh Kumar, R. M.S. ParvathiProblem statement: A large amount of research has been performed to achieve very high data rate networks to support reliable transmission of video, data and speech at high rates to many users. One way to increase the data rate in a wireless system is to use multiple transmit and/or receive antennas (MIMO structure). Indeed, it has been shown that the … …Journal of Computer Science, Vol. 8, Issue 4 · 26 Jan 2012 · 6,759 accessesView PDFCite
Research ArticleOpen accessEvery word in the titleOptimal Decentralized Spectral Resource Allocation for Orthogonal Frequency Division Multiple Access Downlink of Femto Networks Via Adaptive Gradient Vector Step Size ApproachLamia Benmesbah, Bingo Wing-Kuen Ling, Vikram Chandrasekhar et al.Problem statement: For the Orthogonal Frequency Division Multiple Access (OFDMA) downlink of a femto network, the resource allocation scheme would aim to maximize the Area Spectral Efficiency (ASE) subject to constraints on the radio resources per transmission interval accessible by each femtocell. Approach: An optimal resource allocation scheme for completely decentralized femtocell deployments leads to a nonlinear optimization problem because … …American Journal of Engineering and Applied Sciences, Vol. 4, Issue 4 · 14 Jan 2012 · 7,637 accessesView PDFCite