6 articles for “CDMA networks”

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Research ArticleOpen accessEvery word in the titleNeural 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 keywordsTurbo-coding of Coherence Multiplexed Optical PPM CDMA System With Balanced DetectionK. Chitra, V.C. RavichandranThe effects of turbo-coding on the coherence multiplexed optical PPM CDMA systems are shown by evaluating bit error rate (BER) with respect to system parameters such as interleaver length (K), number of simultaneous users (N), code length (f), initial pulsewidth (t0) and normalized threshold (θ) by including the effects of thermal noise and shot noise. Turbo-codes increase the number of … …American Journal of Applied Sciences, Vol. 4, Issue 5 · 31 May 2007 · 6,617 accessesView PDF Cite

Research ArticleOpen accessIn the abstractMultiple 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 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

Review ArticleOpen accessAll words, across the recordA Review on Cognitive Radio for Next Generation Cellular Network and its ChallengesNandhakumar Pandi, Arun KumarCognitive Radio (CR) is considered an intelligent technology. It improves the utilization of the radio spectrum. The increasing number of new devices has resulted in growing congestion of the ISM bands. FCC issued an order only permitting unlicensed users (secondary users) to operate in white space without interfering with licensed users (primary users). Cognitive Radio Networks (CRNs) provides a solution … …American Journal of Engineering and Applied Sciences, Vol. 10, Issue 2 · 4 Apr 2017 · 8,986 accessesView PDF Cite

Research ArticleOpen accessAll words, across the recordKey Success Factors of 3rd Generation Mobile Network Services for M-Commerce in MalaysiaSaravanan MuthaiyahWhile there has been a great deal of excitement in view of M-commerce, very little is actually known about conditions and critical success factors for successful introduction of the 3rd generation mobile network services here in Malaysia. This study investigates the factors for successful diffusion of 3G network services and their role in advancing an interactive marketplace. 3G which simply … …American Journal of Applied Sciences, Vol. 1, Issue 4 · 31 Dec 2004 · 6,876 accessesView PDF Cite