a significant problem in multicarrier communication systems is the necessity to reduce the value of papr (peak-to-average power ratio) of transmitting signal. in this thesis we study the effect of the system parameters such as coding and modulation types on papr and ultimate ber in a mc-cdma system. in this study we consider fading channel as well as the nonlinearity of transmitter’s amplifier ...

abstract the first purpose of this study was to investigate the effect of consciousness-raising (c-r) activities on learning grammatical structures (simple present tense in this case) by iranian guidance school efl learners. the second one was to investigate the effect of gender on learning the simple present tense through c-r activities and tasks. finally, this study aimed to investigate the ...

abstract the present study was conducted in order to investigate the impact of an integrated model of form-focused and task-based instruction on iranian efl learners vocabulary learning and retention.it also aimed to detect efl learners attitude towards the implementation of form-focused task-based vocabulary instruction in the classroom. in order to address the purposes of this study, a sampl...

abstractof two mcall programs introducing 100 vocabulary items through two im the researcher of the present study was intrigued to compare the effects age modalities (pictures and streaming video) with those of a conventional method (teacher instruction) in an efl context. she set out to investigate whether such multimedia environments could provide a more effective environment for vocabulary...

the present study was conducted to investigate the role of summary in teaching grammar process on pre-university students. to this end, 48 male pre-university students in semnan were participants. they were math class that we called experimental group and science class as control group. in order to make sure there was no significant difference in proficiency level of two groups. a pre-test wa...

abstract al- muntazam by ibn al -jawzi is one of the greatest the book ancient book of texts on history of islam in the 6th century.it is very important one;because of including rare reports which are not found any where.in addition to historical reports,his outlook , in which embodies information on mythologies, milal wa nihal (sects and creeds), geography, and political, social and religiou...

one of the most important factors in study of project’s , is the study of environmental opportunities factors the permanent study of environmental opportunity factors . the study of permanent environmental changing and knowing golden threats’ cooperate with possible threats and at the result in structure forming and future skeleton of organization has a vital effects . the petrochemical industr...

the present study aimed at investigating how different news agencies using the concept of legitimation/delegitimation represent the same event differently. to this end, van leeuwens (2008) legitimatory/delegitimatory framework was applied to the data gleaned from the iranian state-run news agency fars news, british state-run news agency bbc, and also american state-run news agency voa. the resu...

the west of esfahan province, iran, is one of the most important agricultural areas throughout the country due to the climate variability and life-giving water of zayanderood river. rice is one of the major and economic crops in this area. the most important climatic elements in agricultural activities which should be considered include temperature, relative humidity, precipitation and wind. so...

background: organic nitrates relax all kinds of smooth muscle , not only vascular smooth muscle , a fact that has allowed the use of these drugs to treat many different aliments. objective.-the purpuse of this study was to examine prosepectively benefical effects , if any, of sublingual nitroglycerin on the pain of renal colic. design.- prospective , randomised , double blind, placebo- contoled...