EM-based adaptive frequency domain estimation of Doppler shifts with CRLB analysis for CDMA systems

Tianqi Wang, Cheng Li, Weixiao Meng, Hsiao Hwa Chen, Mohsen Guizani

Research output: Contribution to journalArticlepeer-review

8 Citations (Scopus)


Combating time and frequency selectivity in wireless channels is one of the most challenging tasks in next generation wireless networks. In this paper, we propose an adaptive estimation algorithm to estimate Doppler shifts in a direct sequence code division multiple access (DS-CDMA) radio system with multiple Doppler subpaths. By modeling doubly selective channels using a basis expansion model (BEM), an expectationmaximization (EM) algorithm based adaptive estimation method is developed to extract accurate Doppler shift information. The Cramer-Rao lower bound (CRLB) analysis is conducted to study the performance bound of the proposed estimation algorithm. Based on the estimated Doppler shift results, a frequency domain equalizer (FDE) based receiver architecture is developed to exploit Doppler diversity in the frequency domain. Our analysis and simulation results demonstrate that this receiver architecture features a low complexity while still achieving a good performance compared with traditional CDMA receivers.

Original languageEnglish
Article number6068203
Pages (from-to)198-208
Number of pages11
JournalIEEE Transactions on Communications
Issue number1
Publication statusPublished - 2012 Jan

All Science Journal Classification (ASJC) codes

  • Electrical and Electronic Engineering


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