4141

3911

كارشناسي ارشد

مخابرات

اصفهان : دانشگاه صنعتي اصفهان ، دانشكده برق و كامپيوتر

1378

نه ، 78 ، [II] ص. : مصور ، نمودار

ص . ع . به : فارسي و انگليسي

علي محمد دوست حسيني

محمد جواد اميدي

20/7/1387

مهندسي برق و كامپيوتر

ID3911

به فارسي و انگليسي : قابل رويت در نسخه ديجينال

AbstractExpansion of wireless networks demand for higher rates limited resources and channel multipath fadingbehavior have led to widespread research for better utilization of the available resources Diversitytechniques in time frequency and space domains are the main tools for fading mitigation and evenexploiting this phenomenon Among various diversity schemes spatial diversity has attracted higherinterest in recent years However due to size and cost constraints all nodes in wireless networks may notbe equipped with multiple antennas In such cases cooperation among users provides the usefulalternative to exploit the intrinsically existing space diversity in the system Research has shown that nextgeneration wireless systems must be cooperative opportunistic and distributed Cooperative diversity asthe boundary between point to point and network communications is a solid candidate for upcomingwireless networks In this thesis fundamentals and various aspects of cooperative diversity have beenintroduced Capacity detection and power allocation in the two main protocols namely Amplify Forward and Decode Forward have been discussed in detail Capacity bounds and ML detector structureshave been derived from source cooperation and space time transmission view points A capacity basedalgorithm for power allocation has been developed for considering two users as information sources as aspecial case of power allocation in multi carrier cooperative diversity It is shown that water filling isoptimal in Decode Forward and may be used iteratively for approaching the optimal power allocation inAmplify Forward Finally recommendations for future works are also proposed

علي محمد دوست حسيني

محمد جواد اميدي