A Low Complexity Resource Allocation A Low Complexity Resource Allocation Algorithm with Increasing Capacity in Algorithm with Increasing Capacity in Cooperative OFDMA Systems Cooperative OFDMA Systems Choong-Wan Park, Won-Chul Choi, Seokkwon Kim and Dong-Jo Park School of Electrical Engineering and Computer Science Korea Advanced Institute of Science and Technology (KAIST) IWCMC 2008
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Choong-Wan Park, Won-Chul Choi, Seokkwon Kim and Dong-Jo Park
A Low Complexity Resource Allocation Algorithm with Increasing Capacity in Cooperative OFDMA Systems. Choong-Wan Park, Won-Chul Choi, Seokkwon Kim and Dong-Jo Park School of Electrical Engineering and Computer Science Korea Advanced Institute of Science and Technology (KAIST). IWCMC 2008. - PowerPoint PPT Presentation
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A Low Complexity Resource Allocation Algorithm with A Low Complexity Resource Allocation Algorithm with Increasing Capacity in Cooperative OFDMA SystemsIncreasing Capacity in Cooperative OFDMA Systems
Choong-Wan Park, Won-Chul Choi, Seokkwon Kim and Dong-Jo Park
School of Electrical Engineering and Computer Science
Korea Advanced Institute of Science and Technology (KAIST)
IWCMC 2008
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OutlineOutline
Introduction System Model and Problem Formulation Proposed Algorithm Simulation Results Conclusion
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IntroductionIntroduction
Dynamic resource allocation Multi-hop orthogonal frequency division multiple access
(OFDMA)
A conventional algorithm not suitable for cooperative OFDMA systems feedback channel gain information (CGI) excessive relay load balancing scheme iterative
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IntroductionIntroduction
The proposed algorithm Low complexity Practical to implement Increases the system capacity
Two types of receiver structures Selection Combining (SC) Maximum Ratio Combining (MRC)
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System Model and Problem FormulationSystem Model and Problem Formulation
In a cooperative OFDMA systems, assume that the BS can know the CGI that reports on the MS the total transmission power of each relay node
Assume The BS allocates the paths, subcarriers and power to the r
elay nodes and an MS A subcarrier is not shared by users
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System Model and Problem FormulationSystem Model and Problem Formulation
No decoding errors
MSMSMSMS
BSBSBSBS
RSRSRSRS
First Half
Second Half
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System Model and Problem FormulationSystem Model and Problem Formulation
Goal Maximizes the system capacity while minimum resources are guaranteed for
each user
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System Model and Problem FormulationSystem Model and Problem Formulation
K: the set of users. N: the set of all subcarriers. L: the set of all OFDM transceivers. ρk,n,l: the nth subcarrier usage index for user k through the lth path. pk,n,l : an allocated power to the lth path of user k in subcarrier n. hk,n,l : the nth subcarrier gain of user k through the lth path. : is the relay peak transmission power of the lrth OFDM transceiver. Rk is the total data rate of the kth user. Sth is the minimum number of subcarriers that should be allocated to each
user.
lrpeakp
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System Model and Problem FormulationSystem Model and Problem Formulation
Conventional Optimization problem
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Proposed AlgorithmProposed Algorithm
A conventional algorithm subcarrier allocation relay load balancing power distribution
2) Efficient Relay Load Balancing step 2: refer to “best2 path”s for each user step 3: calculate the channel gain gap step 4: sort all the channel gain gaps