The Extended-Window Channel Estimator for Iterative Channel-and-Symbol Estimation

Autor: Lopes Renato R., Barry John R.
Jazyk: angličtina
Rok vydání: 2005
Předmět:
Zdroj: EURASIP Journal on Wireless Communications and Networking, Vol 2005, Iss 2, Pp 92-99 (2005)
Druh dokumentu: article
ISSN: 1687-1472
1687-1499
DOI: 10.1155/WCN.2005.92
Popis: The application of the expectation-maximization (EM) algorithm to channel estimation results in a well-known iterative channel-and-symbol estimator (ICSE). The EM-ICSE iterates between a symbol estimator based on the forward-backward recursion (BCJR equalizer) and a channel estimator, and may provide approximate maximum-likelihood blind or semiblind channel estimates. Nevertheless, the EM-ICSE has high complexity, and it is prone to misconvergence. In this paper, we propose the extended-window (EW) estimator, a novel channel estimator for ICSE that can be used with any soft-output symbol estimator. Therefore, the symbol estimator may be chosen according to performance or complexity specifications. We show that the EW-ICSE, an ICSE that uses the EW estimator and the BCJR equalizer, is less complex and less susceptible to misconvergence than the EM-ICSE. Simulation results reveal that the EW-ICSE may converge faster than the EM-ICSE.
Databáze: Directory of Open Access Journals
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