Resource Allocation with Imperfect CSI in OFDMA Environments

碩士 === 國立中央大學 === 通訊工程學系 === 101 === The design of resource allocation in OFDMA environments have been assumed that perfect channel state information (CSI) can be estimated in previous researches. However, it is rarely possible to get perfect CSI due to channel estimation error and feedback delay. H...

Full description

Bibliographic Details
Main Authors: Cheng-han Ho, 何承翰
Other Authors: Jia-chin Lin
Format: Others
Language:zh-TW
Published: 2013
Online Access:http://ndltd.ncl.edu.tw/handle/00683937732985125043
Description
Summary:碩士 === 國立中央大學 === 通訊工程學系 === 101 === The design of resource allocation in OFDMA environments have been assumed that perfect channel state information (CSI) can be estimated in previous researches. However, it is rarely possible to get perfect CSI due to channel estimation error and feedback delay. Hence,the algorithm to solve imperfect CSI draws much more attention. In order to reduce computation amount for system, we have discussed the chunk allocation technique in OFDMA environments with perfect CSI and combine this technique into our proposed scheme in OFDMA environments with imperfect CSI. In this thesis, we proposed a novel resource allocation algorithm called “envy-free resource allocation” which could reduce the envy behavior among users due to unequal allocated resources in OFDMA environments. The proposed scheme minimizes the total average rate difference between each pair of users, subject to average BER constraints for each allocated subcarrier. Simulation results show that, a larger allocated number of chunks could guarantee a smaller total average rate difference between users, resulting in a much smaller chance for users to envy each other. Furthermore, when the allocated chunk number is big enough, then the performance of users with unequal additive error is close to users with equal additive error.