9219

8521

كارشناسي ارشد

مخابرات

اصفهان: دانشگاه صنعتي اصفهان، دانشكده برق و كامپيوتر

1393

سيزده،96ص.: مصور

ص.ع.به فارسي و انگليسي

محمدصادق فاضل

فروغ سادات طباطبا

7/8/93

مهندسي برق و كامپيوتر

ID8521

Subcarrier allocation in OFDMA based Two way Relaying networks Mohammad Mashayekhi m mashayekhi@ec iut ac ir Date of Submission 2014 08 23 Department of Electrical and Computer Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language Farsi Supervisor Mohamad Sadegh Fazel fazel@cc iut ac ir Abstract Todays various internet services and portable handheld devices have increased demands for wireless internet services Since there are many demands for high data rate services in recent years wireless technology have developed from first generation audio to present complex high data rate generation The standards for 4th generation of mobile networks have been designed in order to provide high data rate for mobile users Besides OFDM multicarrier technique has been used frequently as a method for earning high data rates This technique can overcome major problems such as frequency selective fading channel and inter symbol interference ISI because of its nature Furthermore relaying transmission methods have attracted many attentions recently therefore relay technology in combination with OFDM is considered as an effective approach in fourth generation mobile networks In these networks there are some important resources such as power subcarriers which their allocation method to users has very important effect on overall network performance and each allocation algorithm has its own advantages and disadvantages In this thesis we investigate performance of different relaying schemes in a two way multiuser single relay network with Amplify and Forward protocol in relays combined with OFDMA method for data transmission Essentially our goal is to maximize overall network achievable data rate considering limited powers on each network node There are four different two way relaying scenarios depends on different number of time phases in data transmission and existence of direct link For each relaying scenario at first we introduce resource allocation problem and since finding optimum solution is very complex a new suboptimum subcarrier allocation method is presented which provide better performance results compared to the previous presented suboptimum method in all 2 phase 3 phase and 4 phase scenarios Keywords Resource allocation Amplify and Forward AF OFDMA Two way relaying Multiuser

محمدصادق فاضل

فروغ سادات طباطبا