Title :
EM-based sparse channel estimation in OFDM systems
Author :
Carvajal, Rodrigo ; Godoy, Boris I. ; Agüero, Juan C. ; Goodwin, Graham C.
Author_Institution :
Centre for Complex Dynamic Syst. & Control, Univ. of Newcastle, Newcastle, NSW, Australia
Abstract :
In this paper, we address the problem of estimating sparse communication channels in OFDM systems. We consider the case where carrier frequency offset is present. The problem of estimation is then approached by maximizing a regularized (modified) likelihood function. This regularized likelihood function includes a new term accounting for the a priori probability density function for the parameters, represented by a Gaussian mean-variance mixture. The maximization of the regularized likelihood function is carried out by using the Expectation-Maximization (EM) algorithm. We show that the E-step in the proposed algorithm has a closed-form solution, and in the M-step, the cost function is concentrated in one variable (carrier frequency offset).
Keywords :
Gaussian processes; OFDM modulation; channel estimation; expectation-maximisation algorithm; probability; EM-based sparse channel estimation; Gaussian mean-variance mixture; OFDM system; carrier frequency offset; cost function; expectation-maximization algorithm; probability density function; regularized likelihood function; sparse communication channel; Channel estimation; Maximum likelihood estimation; OFDM; Signal processing algorithms; Training; Wireless communication;
Conference_Titel :
Signal Processing Advances in Wireless Communications (SPAWC), 2012 IEEE 13th International Workshop on
Conference_Location :
Cesme
Print_ISBN :
978-1-4673-0970-7
DOI :
10.1109/SPAWC.2012.6292965