58 results for “SNR”

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Research ArticleOpen accessIn the abstractPerformance Analysis of Global Search Algorithm Based Multiuser Detector for Multi Carrier Code Division Multiple Access System under Clipping NoiseS. Sivanesskumar, R. SukaneshProblem statement: Multi Carrier Code Division Multiple Access (MC-CDMA), a promising technology for the 4G communication systems. The major limitation of MC-CDMA system is the Multiple Access Interference (MAI) which is due to near-far effect, frequency offset and nonlinear power amplification due to clipping noise. Approach: The performance of MC-CDMA under clipping noise using Global search algorithm based Multiuser detector … …Journal of Computer Science, Vol. 7, Issue 5 · 7 May 2011 · 6,687 accessesView PDF Cite

Research ArticleOpen accessIn the abstractA New Robust Hybrid Approach to Enhance Speech in Mobile Communication SystemsManimegalai Govindan Sumithra, Keppana Gounder Thanuskodi, Bharathi DeepaProblem statement: The received voice signal in mobile communication is often disturbed by background noise and hence there is a need for good noise reduction methods for enhancing Speech. It is well known that denoising is a compromise between the removal of the largest possible amount of noise and the preservation of signal integrity. To address this issue, a new … …American Journal of Applied Sciences, Vol. 8, Issue 4 · 18 Apr 2011 · 7,299 accessesView PDF Cite

Research ArticleOpen accessIn the abstractSolving the Near-Far Problem in Dynamic Frequency Hopping-Optical Code Division Multiple Access using Power ControlW. J.M. Al-galbi, M. Mokhtar, A. F. Abas et al.Problem statement: In this study, a distributed power control algorithm is proposed for Dynamic Frequency Hopping Optical-CDMA (DFH-OCDMA) system. Approach: In general, the DFH-OCDMA can support higher number of simultaneous users compared to other OCDMA techniques. However, the performance of such system degrades significantly as the received power does lower than its minimum threshold. Results: This may obviously occur in … …Journal of Computer Science, Vol. 5, Issue 6 · 30 Jun 2009 · 7,521 accessesView PDF Cite

Research ArticleOpen accessIn the abstractOn the Probability Density Function of the Test Statistic for One Nonlinear GLR Detector Arising from fMRIFangyuan NanRecently an important and interesting nonlinear generalized likelihood ratio (GLR) detector emerged in functional magnetic resonance imaging (fMRI) data processing. However, the study of that detector is incomplete: the probability density function (pdf) of the test statistic was draw from numerical simulations without much theoretical support and is therefore, not firmly grounded. This correspondence presents more accurate (asymptotic) closed form … …Journal of Mathematics and Statistics, Vol. 3, Issue 2 · 30 Jun 2007 · 7,106 accessesView PDF Cite

Research ArticleOpen accessIn the abstractSpeech Enhancement Based on Adaptive Noise Cancellation and Particle Swarm OptimizationTayseer M.F. Taha, Summrina Kanwal Wajid, Amir HussainSpeech enhancement is used in almost all modern communication systems. This is due to the quality of speech being degraded by environmental interference factors, such as: Acoustic additive noise, acoustic reverberation or white Gaussian noise. This paper, explores the potential of different benchmark optimization techniques for enhancing the speech signal. This is accomplished by fine tuning filter coefficients using a … …Journal of Computer Science, Vol. 15, Issue 5 · 28 May 2019 · 7,729 accessesView PDF Cite

Research ArticleOpen accessIn the abstractUNUSUAL SPECTRUM OF GENETIC PATHOLOGIES AND NOVEL MUTATIONS IN PWS AND AS PATIENTS DETECTED BY A WIDE CLUSTER OF METHODSLivia Kotysova, Robert Petrovic, Jan ChandogaPrader-Willi and Angelman syndromes are clinically distinct neurodevelopmental genetic disorders that map to 15q11.2-q13 locus. The common phenotypes are attributable to loss of expression of parentally specific imprinted genes inside this region, where the gene function is dependent on parental origin. Initial diagnosis was proved for the years by methylation pattern analyses of the SNRPN exon 1/promoter region within the … …OnLine Journal of Biological Sciences, Vol. 14, Issue 3 · 12 Nov 2014 · 7,006 accessesView PDF Cite

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 · 7,570 accessesView PDF Cite

Research ArticleOpen accessIn the abstractIterative Channel Estimation Algorithm in Multiple Input Multiple Output Orthogonal Frequency Division Multiplexing SystemsMona Nasseri, Hamidreza BakhshiProblem statement: The objective of this study is improving channel estimation accuracy in MIMO-OFDM system because channel state information is required for signal detection at receiver and its accuracy affects the overall performance of system and it is essential to improve the channel estimation for more reliable communications. MIMO-OFDM system was chosen in this study because it has been widely … …Journal of Computer Science, Vol. 6, Issue 2 · 28 Feb 2010 · 8,297 accessesView PDF Cite