Title :
Basis Expansion Model and Doppler Diversity Techniques for Frequency Domain Channel Estimation and Equalization in DS-CDMA Systems
Author :
Tianqi Wang ; Cheng Li ; Chen, Hsiao-hwa
Author_Institution :
Memorial Univ. of Newfoundland, St. John´s
Abstract :
In this paper, we propose a frequency domain adaptive estimation of Doppler shifts for multiple Doppler subpaths in direct sequence code division multiple access (DS-CDMA) systems. By modeling the doubly selective channel using a basis expansion model (BEM), the proposed expectation-maximization (EM) algorithm-based estimation method can obtain accurate information of Doppler shifts. Based on the estimated information of Doppler shifts, a FDE-based receiver architecture is developed to exploit Doppler diversity in frequency domain. Simulation results demonstrate that this receiver structure features a low computational complexity while achieving good performance compared with traditional receiver structures in DS-CDMA systems.
Keywords :
Doppler effect; channel estimation; code division multiple access; equalisers; expectation-maximisation algorithm; frequency-domain analysis; spread spectrum communication; DS-CDMA systems; Doppler diversity; basis expansion model; channel equalization; direct sequence code division multiple access systems; expectation-maximization algorithm-based; frequency domain channel estimation; multiple Doppler subpaths; Adaptive estimation; Channel estimation; Computational complexity; Computational modeling; Computer architecture; Direct-sequence code-division multiple access; Doppler shift; Frequency domain analysis; Frequency estimation; Multiaccess communication;
Conference_Titel :
Communications, 2007. ICC '07. IEEE International Conference on
Conference_Location :
Glasgow
Print_ISBN :
1-4244-0353-7
DOI :
10.1109/ICC.2007.810