Title :
Joint 2D-pilot-symbol-assisted-modulation and decision-directed frequency synchronization schemes for coherent OFDM
Author :
Garcia, M. Julia Fernández- Getino ; Edfors, Ove ; Paez-Borrallo, J.M.
Author_Institution :
Dept. de Senales, Sist. y Radiocom, Univ. Politecnica de Madrid, Spain
Abstract :
A new frequency offset tracking approach for OFDM has been addressed. Two-dimensional pilot-symbol assisted modulation (2D-PSAM) is employed in coherent OFDM for channel estimation and it is based on inserting known symbols spread out through the 2D time-frequency grid. We show that these scattered symbols can also be employed to perform frequency synchronization. Maximum likelihood estimation has been derived for both time and frequency domains. Also, if a decision-guided strategy is used jointly with the 2D-PSAM signalling, an improvement in performance can be attained
Keywords :
OFDM modulation; maximum likelihood estimation; parameter estimation; synchronisation; telecommunication channels; telecommunication signalling; tracking; 2D time-frequency grid; 2D-PSAM signalling; channel estimation; coherent OFDM; decision-directed frequency synchronization; decision-guided strategy; frequency domain; frequency offset tracking; joint 2D-pilot-symbol-assisted-modulation; maximum likelihood estimation; performance; scattered symbols; time domain; Channel estimation; Doppler shift; Frequency domain analysis; Frequency estimation; Frequency synchronization; Gaussian noise; Maximum likelihood estimation; OFDM modulation; Oscillators; Scattering;
Conference_Titel :
Acoustics, Speech, and Signal Processing, 2000. ICASSP '00. Proceedings. 2000 IEEE International Conference on
Conference_Location :
Istanbul
Print_ISBN :
0-7803-6293-4
DOI :
10.1109/ICASSP.2000.861155
