期刊名称:Journal of Theoretical and Applied Information Technology
印刷版ISSN:1992-8645
电子版ISSN:1817-3195
出版年度:2013
卷号:53
期号:3
出版社:Journal of Theoretical and Applied
摘要:Pilot-assisted channel estimation has been studied only in common cooperative AF (Amplify-and-Forward) OFDM which has no feedback mechanism. In this paper, for cooperative AF-OFDM system, we propose a feedback technique in which the pilot allocation mechanism is adapted to the cooperative mobile channel. Then we show how uniform pilots may no longer be optimal compared with our pilots. After deducing the instantaneous system SNR is the function of the pilot allocation, we optimize the pilot locations using optimization method at the destination node. We examine the feedback overhead that is associated with our method and make comparisons with the conventional uniform pilot allocation. To improve system capacity, we suggest reduce the feedback information using K-means clustering algorithm. Simulation results confirmed that the proposed optimization method has an ideal performance gains and the algorithm of feedback reduction can reduce the feedback information under the premise of ideal performance.
关键词:AF-OFDM system; Feedback mechanism; Optimization of pilot allocation; Reduce feedback.