Parameter Estimation of RAKE Receiver Using the EM Algoritm

• Main Authors: Chia-Wei Pai, 白嘉煒
• Other Authors: Jung-Jae Chao
• Format: Others
• Language: zh-TW
• Published: 1999
• Online Access: http://ndltd.ncl.edu.tw/handle/30804610925140418226

碩士 === 國立海洋大學 === 航運技術研究所 === 87 === We employ the RAKE receiver with EM (expectation-maximization) algorithm to solve the problems of multipath propagation and fading. The key issue is to decompose the observed data into their channel components, then to estimate the unknown parameters of each channel separately. Using the maximal ratio combiner, the estimated parameters are applied to the RAKE receiver to improve the performance. EM algorithm produces maximum-likelihood estimates of parameters when there is a many-to-one mapping from an underlying distribution to the distribution governing the observed data. With the property of convergence, the algorithm is iterated with increasing likelihood. As a result, the proposed RAKE receiver has a better performance than the traditional one in terms of BER.