Application of LMS Algorithm with Fuzzy Updated Step Size on Channel Prediction for OFDM Systems

• Main Authors: Cheih-Yao Chang, 張傑堯
• Other Authors: Jyh-Horng Wen
• Format: Others
• Language: en_US
• Published: 2006
• Online Access: http://ndltd.ncl.edu.tw/handle/50166153743521180527

碩士 === 國立中正大學 === 電機工程所 === 94 === The adaptive filter applied to channel predictor for orthogonal frequency division multiplexing (OFDM) systems is investigated. Different algorithms of adaptive filter, such as normalized least mean square (NLMS) and recursive least square (RLS), are applied to predict the channel response. We proposed the algorithm which is based on the least mean square (LMS) and periodically updates the step size by a fuzzy logic controller. The computation load of proposed algorithm is smaller than both NLMS and RLS algorithms. The simulation results show that the tracking ability of proposed algorithm is slightly better than the NLMS algorithm. Therefore, the proposed algorithm is an efficient method which can be applied to channel prediction.