5823

5438

كارشناسي ارشد

مخابرات

اصفهان: دانشگاه صنعتي اصفهان، دانشكده برق و كامپيوتر

1389

ده،105ص.: مصور،جدول،نمودار

ص.ع.به فارسي و انگليسي

مهدي مهدوي، ابوالقاسم زيدآبادي نژاد

5/2/90

پژمان خديوي، نغمه السادات مويديان

مهندسي برق و كامپيوتر

ID5438

به فارسي و انگليسي: قابل رويت در نسخه ديجيتالي

105 New Schedualing algorithms and Resource Allocation and Relay Stations Placement for Increasing Capacity in Multihop Network Based on IEEE 802 16j Standard Tayebeh GHolipur Ta gholipur@yahoo com Date of Submission 20010 11 28 Department of Electrical and Computer Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language Farsi Supervisor Mehdi Mahdavi m mahdavi@cc iut ac ir Abolghasem Zeidabadinegad zeidabad@cc iut ac ir Abstract One of the most important challenges exists in WiMAX network is the problem of non line of sight In this kind of link the problem is loss of power caused by diffusion of waves into the building and access to coverage extension one of the solution of this trouble is using relays in the network which improves signal s quality IEEE 802 16j standard method that is related to multi hop network is designed for this purpose In addition one of the key points in multi hop networks is the places in which relays are located in order to increase the capacity A great deal study has been done in this area so far In these researches the criterion of finding the best position of relays in network is network s capacity based on physical layer while scheduling algorithm and resource allocation is one crucial factor in network s capacity which is neglected in the studies So in this dissertation common scheduling algorithms are investigated to estimate the influence of them on finding the location of relays Since most of the algorithms have a weak point two algorithms were firstly put forward and then a procedure is proposed to find the place of relays In the presented method in order to determine the place of relays the properties of both medium access control layer and physical layer are considered It should be taken into account that in majority of studies in the area of scheduling and resource allocation algorithms for the purpose of increasing network s capacity it is assumed that coherence time of user channel is more than time length of a frame however it may not be correct Consequently in proposed scheduling algorithms and resource allocation the situation of physical link of operators is specially considered Furthermore these algorithms are useful when coherence time of user channel is less than time length of a frame Key words multi hop network relay scheduling algorithm and resource allocation coherence time

مهدي مهدوي، ابوالقاسم زيدآبادي نژاد

پژمان خديوي، نغمه السادات مويديان