Title :
Maximum Likelihood Estimation and Correction of Carrier Frequency Offset in OFCDM Systems
Author :
Khalid, Lamiaa ; Anpalagan, Alagan
Author_Institution :
WINCORE Lab., Ryerson Univ., Toronto, ON
Abstract :
In this paper, a Carrier Frequency Offset (CFO) correction scheme is proposed for a downlink Variable Spreading Factor (VSF) OFCDM system based on the maximum likelihood principle. We first derive the likelihood function for VSF- OFCDM system with CFO, and then propose to use a gradient algorithm to estimate and minimize the effect of CFO in a tracking mode. The maximal ratio combining receiver is considered for detection. Our results show that the BER performance in the low SNR environment can be improved significantly with few number of iterations.
Keywords :
OFDM modulation; code division multiple access; gradient methods; maximum likelihood estimation; carrier frequency offset correction scheme; gradient algorithm; maximum likelihood estimation; orthogonal frequency and code division multiplexing; variable spreading factor OFCDM system; Bit error rate; Diversity reception; Downlink; Frequency diversity; Frequency domain analysis; Frequency estimation; Maximum likelihood estimation; Multicarrier code division multiple access; Multiple access interference; OFDM;
Conference_Titel :
Global Telecommunications Conference, 2008. IEEE GLOBECOM 2008. IEEE
Conference_Location :
New Orleans, LO
Print_ISBN :
978-1-4244-2324-8
DOI :
10.1109/GLOCOM.2008.ECP.848
