16 results for “MC-CDMA System”

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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 · 6,881 accessesView PDF Cite

Research ArticleOpen accessIn the abstractEfficient Detection Algorithm for a Multiple-Input and Multiple-Output Multiuser Multi-Carrier Code Division Multiple Access in Time-Varying ChannelsFares Sayadi, Mahamod Ismail, Norbahiah Misran et al.Problem statement: Maximum Likelihood (ML) decoding has been applied for the uplink of a Multi-Carrier Code Division Multiple Access (MC-CDMA) system based on Orthogonal Frequency Division Multiplexing (OFDM). Multiple-Input Multiple-Output (MIMO) channel from k users, which moves at vehicular speed, to the Base-Station (BS) is time-varying. For time-varying channels, Sphere Decoding (SD) was introduced to perform ML decoding. Whereas, computational … …American Journal of Engineering and Applied Sciences, Vol. 2, Issue 4 · 31 Dec 2009 · 7,576 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 abstractMAI Cancellation in DS/CDMA using a new Approach on WDSY. Jabrane, R. Iqdour, B. Ait Es said, N. NajaThe steeping chip weighting waveforms are used in Multiple Access Interference cancellation by emphasizing the received spreading signal, therefore, that allows to solve the problem of orthogonality for the chip waveforms. The goal of this study was to elaborate a useful method based on fuzzy systems to determine the despreading sequences weighted by the steeping chip weighting waveforms for Direct … …American Journal of Applied Sciences, Vol. 4, Issue 10 · 31 Oct 2007 · 6,884 accessesView PDF Cite

Research ArticleOpen accessIn the abstractNeural Networks for Interferences Suppression in DS/CDMA with Rayleigh Fading Channel and Power Control ErrorY. Jabrane, R. Iqdour, B. Ait Essaid et al.The exponential chip weighting waveforms have been designed with the purpose of multiple access interferences (MAI) rejection based on the concept that the optimum despreading sequence in reference emphasizes the transitions in the received spreading signal of interest. The despreading sequence weighted by exponential chip waveforms was determined by only one parameter. The objective of this study, was to introduce … …Journal of Computer Science, Vol. 3, Issue 3 · 31 Mar 2007 · 6,382 accessesView PDF Cite

Research ArticleOpen accessIn the abstractImplementation of a Novel Concatenated FEC by RS and Irregular Turbo Codes on OFDM SystemsA. Shanmugam, A. R. Abdul Rajak, S. Vishwanath, R. UpendraCode Division Multiple Access (CDMA) performs well in a multi-cellular environment where a single frequency is used in all cells. Code Division Multiple Access (CDMA) has severe problems associated with multipath and Channel news. One possible problem is that the receiver may require a very large dynamic range in order to handle the large signal strength variation among users. Due … …American Journal of Applied Sciences, Vol. 2, Issue 5 · 31 May 2005 · 7,039 accessesView PDF Cite