16 results for “Multipath Channel”

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Research ArticleOpen accessIn the abstractPerformance Evaluation of Wireless Sensor Network Channel in Agricultural ApplicationNaseer Sabri, S. A. Aljunid, R. B. Ahmad et al.Problem statement: In this study, the behavior of small scale fading channel due to a moving sink node of a Wireless Sensor Network (WSN) or moving of surrounding objects is presented. Approach: Specifically, this research introduces the effects of multipath and scattering on the transmitted signal due to mobile sink node within forest or closed field filled of reflectors and … …American Journal of Applied Sciences, Vol. 9, Issue 1 · 24 Nov 2011 · 7,096 accessesView PDF Cite

Research ArticleOpen accessIn the abstractA New Approach for Sub-Channels Assignment in Downlink Fourth Generation Mobile SystemsFakhreddine Khelifa, Abdelaziz SametProblem statement: We proposed a new heuristic method for subchannels allocation problem in the context. Approach: In this system, OFDM transmission method has been used, in order to reduce the effect of multipath fading, OFDMA to achieve multiple access schemes and flexibility in resource allocation. Results: An adaptive method for subchannels allocation is necessary in order to exploit the multiuser … …Journal of Computer Science, Vol. 7, Issue 9 · 23 Jul 2011 · 6,588 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 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

Research ArticleOpen accessIn the abstractFrequency Extended-MUSIC Method for DOA Estimation in Indoor IR-UWB EnvironmentHajer Meknessi, Ferid Harrabi, Ali GharsallahIn recent years, many researchers have been developed in order to ensure an accurate localization. So many techniques have been used the direction of arrival to estimate and track of IR-UWB signals. In this study, we propose a new direction of arrival estimation method for impulse radio UWB signals. This technique based on Extended-Music algorithm. The proposed method has high … …American Journal of Applied Sciences, Vol. 13, Issue 4 · 8 Apr 2016 · 7,285 accessesView PDF Cite

Research ArticleOpen accessAll words, across the recordNeural 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