4129

3913

كارشناسي ارشد

مخابرات

اصفهان : دانشگاه صنعتي اصفهان : دانشكده برق و كامپيوتر

1387

نه ، 74 ، [II] ص . : نمودار

ص . ع . به : فارسي و انگليسي

علي محمد دوست حسيني

محمد جواد اميدي

20/7/1387

محمود مدرس هاشمي / محمد دخيل عليان

مهندسي برق و كامپيوتر

ID3913

به فارسي و انگليسي : قابل رويت در نسخه ديجيتال

AbstractExploiting spatial diversity and space time codes multi input multi output MIMO communication systems provide high spectral efficiency and low bit error rate Therefore these systems have attracted much attention in the last decade MIMO communication systems rely strongly on the channel state information So channelestimation is an essential step in implementation of these systems and different estimationmethods such as training based blind and semi blind schemes have been proposed accordingto channel time variations In this thesis channel model for MIMO communication systems under various frequency andtime fading states is studied A few training based estimation methods and the correspondingmost desirable training sequences that minimize the mean square error MSE are introduced Also time variation of the channel and some tracking methods in time varying channels arestudied Then the effect of considering spatial correlation among different sub channels inthe estimation and tracking of channel coefficients are investigated In the case of blockfading channels a method in which the output of the least square estimator is exploited toestimate the channel correlation matrix and noise variance with the same training sequencesis proposed Using the MMSE estimator the effect of appropriate deployment of the channelcorrelation matrix in reducing the estimation error compared to the methods that ignorecorrelation among different sub channels is investigated Also in the case of non blockfading channels considering spatial correlation in addition to the temporal correlation amongsub channels state space model of the channel is modified and the effect of this modificationin decreasing the channel tracking error is presented via computer simulations

علي محمد دوست حسيني

محمد جواد اميدي