Sharif Digital Repository

UMTS is the European standard of third generation of mobile communications and its air interface is called WCDMA. In this paper a simple WCDMA system in downlink and in FDD mode is simulated and results is presented. The simulation that is an execution of apart of physical layer functions as layer 1, is including data modulation, spreading multipath channel, AWGN noise, data demodulation, despreading and Rake receiver. It is obvious that transmission methods of data correspond with WCDMA standard. In the other word, frames and slots structure, data symbols setting and requiring parameters follow the defined standards  

UMTS is the European standard of the third generation of mobile communications and its air interface is called WCDMA. In this paper a simple WCDMA system in downlink and FDD mode is simulated and results are presented. The simulation that is an execution, apart from physical layer functions as layer 1, includes data modulation, spreading multipath channel, AWGN noise, data demodulation, despreading and Rake receiver. It is obvious that transmission methods of data correspond to WCDMA standards. In other words, frames and slots structure, data symbols setting and required parameters follow the defined standards. © 2002 St. Petersburg State Poly Univ  

Objectives: This study takes the guaranteed quality of service for operators and service providers into consideration and challenges the discussions on service assurances such as mathematical and statistical analyses of quality indicators to achieve the significance of elements relevant to the services. Methods/Analysis: In order to ensure the process, Enhanced Telecom Operation Map (ETOM) framework has been applied, the procedure is tested on the Executive Network of Iran Telecommunication Research Center (mail services) due to the lack of a practical context of UMTS network (3G). Findings: The result was to achieve a practical and logical way characterizing coefficients of significance and... 

The effect of the nucleating agent masterbatch carrier resin on the nonisothermal crystallization of a pipe-grade polypropylene block copolymer was investigated at three different cooling rates using differential scanning calorimetry (DSC). Bis(3,4-dimethylibenzylidene) sorbitol (DMDBS), a well-known, third-generation sorbitol derivative, was used as a nucleating agent in this study. Crystallization kinetic parameters obtained from DSC cooling curves showed that incorporation of a nucleating agent by means of a masterbatch increased the crystallization rate by approximately two times compared to that of the sample with the same concentration of nucleating agent without the use of a... 

We introduce a new third generation of solar cell structure which inserts different-sized quantum dots in the active region of a pin structure. Generating an intermediate band in the bandgap of the host material makes a good overlap with a part of solar spectrum. The effect of the recombination mechanisms on efficiency and currentvoltage characteristics of this intermediate band solar cell is calculated. We deduce that the increase in recombination lifetime of the excited carriers can improve the characteristics of this structure. This result can be a route which helps us to take the effect on solar cell characteristics into consideration  

The aim of the present study is to provide an Atlas of IRAN Offshore Renewable Energy Resources (hereafter called 'the Atlas') to map out wave and tidal resources at a national scale, extending over the area of the Persian Gulf and Sea of Oman. Such an Atlas can provide necessary tools to identify the areas with greatest resource potential and within reach of present technology development. To estimate available tidal energy resources at the site, a two-dimensional tidally driven hydrodynamic numerical model of Persian Gulf was developed using the hydrodynamic model in the MIKE 21 Flow Model (MIKE 21HD), with validation using tidal elevation measurements and tidal stream diamonds from...