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113 articles for “Channel State”
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Research ArticleOpen accessIn the abstractAnalytical Modeling of IEEE 802.11e Enhanced Distributed Channel Access under a Non-Saturation ConditionG. Prakash, P. ThangarajProblem statement: The IEEE 802.11e EDCA protocol with different access Categories (ACs) supporting for Quality-of-Service (QoS). Due to internal or external packet collision, the Contention Window (CW) of the station increases the channel idle time under high Bit Error Rate (BER). Approach: In this study, we propose an analytical model for performance evaluation of IEEE 802.11e EDCA scheme under non-saturation … …Journal of Computer Science, Vol. 7, Issue 4 · 4 Apr 2011 · 7,099 accessesView PDFCite
Research ArticleOpen accessIn the abstractPerformance Analysis of IEEE 802.16d using Forward Error CorrectionVenkatesh Sekar, V. Palanisamy, K. BaskaranProblem statement: Worldwide Interoperability for Microwave Access is the broadband wireless technology for terrestrial broadcast services in Metropolitan Area Networks. This BWA technology is based on Orthogonal Frequency Division Multiplex (OFDM) technology and considers the radio frequency range up to 2-11 GHz and 10-66 GHz. The objective of this research work is the performance analysis of AWGN, SUI-1 and SUI-2 … …Journal of Computer Science, Vol. 7, Issue 3 · 9 Mar 2011 · 7,343 accessesView PDFCite
Research ArticleOpen accessIn the abstractPerformance Analysis of Multi-user Multi Input Multi Output- Interleave-Division Multiple-Access System Employing Turbo Coding with Multi-User Detection over Frequency-Selective Wireless Communication ChannelKuttathatti Srinivasan Vishvaksenan, R. Seshasayanan, Yuvaraj KrishnamoorthyProblem statement: This study presents the performance analysis of multi-user Multi Input Multi Output (MIMO) assisted interleave based multiple-access system. In IDMA, different interleavers are used to distinguish users as against different signature sequence in a conventional code-Division Multiple-Access (CDMA) scheme. Approach: The basic principle of IDMA is that the interleaver is unique for the users. Results: In this study, … …Journal of Computer Science, Vol. 7, Issue 2 · 25 Feb 2011 · 6,885 accessesView PDFCite
Research ArticleOpen accessIn the abstractPerformance Evaluation of Multi-Pulse Based Code Excited Linear Predictive Speech Coder with Bitrate Scalable Tool over Additive White Gaussian Noise and Rayleigh Fading ChannelsSuphattharachai ChomphanProblem statement: In the modern speech communication technology, the speech coding with bitrate scalability was needed. However, various types of noises in the communication channels cause damages in the transmitted information especially speech data. Tonal-language speech was also affected by this situation. Approach: Based on the high pitch delay resolution technique, the MPCELP speech coding was proposed over the environment … …Journal of Computer Science, Vol. 6, Issue 12 · 6 Nov 2010 · 7,090 accessesView PDFCite
Research ArticleOpen accessIn the abstractProducing Television Agriculture Program: Issues and Problems among Malaysian Television ProducersMd. Salleh Hassan, Hayrol Azril Mohamed Shaffril, Bahaman Abu Samah et al.Problem statement: One of the developing sectors in Malaysia is agriculture. Agriculture doubtlessly has assisted this country in terms of enhancing the economic level, offering a huge number of employment opportunities and uplifting the socio-economy status of the community. To ensure the sustainability of this sector to the country, we must ensure that the valuable agriculture information is continuously provided … …Journal of Social Sciences, Vol. 6, Issue 3 · 30 Sep 2010 · 8,165 accessesView PDFCite
Research ArticleOpen accessIn the abstractThe Horizontal Electric Field Induced by a Lightning Return StrokeScott L. Meredith, Susan K. Earles, Niescja E. TurnerProblem statement: Develop a new formula which describes the horizontal electric field induced by a lightning return stroke in contact with an imperfect conductive surface. Approach: A new method for describing the horizontal electric field induced by a lightning return stroke will be presented. The method presented here had utilized an approach which purposely downplayed the physics of how image … …Journal of Mathematics and Statistics, Vol. 6, Issue 3 · 30 Sep 2010 · 7,420 accessesView PDFCite
Research ArticleOpen accessIn the abstractSafety Message Power Transmission Control for Vehicular Ad hoc NetworksGhassan Samara, Sureswaran Ramadas, Wafaa A.H. Al-SalihyProblem statement: Vehicular Ad hoc Networks (VANET) is one of the most challenging research area in the field of Mobile Ad Hoc Networks. Approach: In this research we proposed a dynamic power adjustment protocol that will be used for sending the periodical safety message. (Beacon) based on the analysis of the channel status depending on the channel congestion and the … …Journal of Computer Science, Vol. 6, Issue 10 · 30 Jul 2010 · 7,470 accessesView PDFCite
Research ArticleOpen accessIn the abstractHistory Based Contention Window Control in IEEE 802.11 MAC Protocol in Error Prone ChannelAli Balador, Ali Movaghar, Sam JabbehdariProblem statement: IEEE 802.11 Medium Access Control (MAC) protocol is one of the most implemented protocols in this network. The IEEE 802.11 controls the access to the share wireless channel within competing stations. The IEEE 802.11 DCF doubles the Contention Window (CW) size for decreasing the collision within contending stations and to improve the network performances but it is not … …Journal of Computer Science, Vol. 6, Issue 2 · 28 Jul 2010 · 7,667 accessesView PDFCite
Research ArticleOpen accessIn the abstractPerformance of Orthogonal Frequency Division Multiplexing System Based on Mobile Velocity and SubcarrierZulkeflee Bin Khalidin, Haitham J. TahaProblem statement: Nowadays, the mobile telecommunications industry faces the problem of providing the technology that be able to support a wide variety of services ranging from voice communication with a bit rate of a few kbps to wireless multimedia in which bit rate up to 2 Mbps. Approach: This study introduced a new performance study to enhance the Orthogonal Frequency … …Journal of Computer Science, Vol. 6, Issue 2 · 28 May 2010 · 7,043 accessesView PDFCite
Research ArticleOpen accessIn the abstractA Preamble-Based Frequency Offset Compensation Scheme in Multiple Input Multiple Output Orthogonal Frequency Division Multiplexing SystemsElnaz Ershadi, Hamidreza BakhshiProblem statement: Combining the properties of Multiple Input Multiple Output (MIMO) systems with those of Orthogonal Frequency Division Multiplexing (OFDM), MIMO-OFDM was considered to be a promising technique in the future of wireless communications. However, its sensitivity to frequency offsets which results in Inter-Carrier Interferences (ICIs) makes it necessary to use an exact frequency offset estimation method for data recovery … …Journal of Computer Science, Vol. 6, Issue 4 · 30 Apr 2010 · 7,574 accessesView PDFCite