Title :
Downlink channel estimation and tracking in mobile WiMAX systems
Author :
Mohamad, M.F. ; Saeed, M.A. ; Priantoro, A.U.
Author_Institution :
Wireless Broadband, MIMOS Berhad, Kuala Lumpur
Abstract :
Mobile WiMAX is a new promising technology based on IEEE 802.16-2005 that supports high-speed, broadband fixed and mobile services through using orthogonal frequency division multiple access (OFDMA). In mobile communications, channel estimation is important for system performance, but at the same time it is very crucial when the fading channel is fast time-varying. In this paper, a cluster-based downlink channel estimation and tracking in mobile WiMAX is evaluated based on least square (LS) methods. Interpolation between channel estimates at pilots is carried out both over frequency and time to compensate between high data transfer rate as well as efficient channel estimation. Simulation results in terms of mean square error (MSE) and bit error rate (BER) show that channel estimation over two OFDM symbols exhibits better performance compared to that of single OFDM symbol even at high Doppler frequencies.
Keywords :
OFDM modulation; WiMax; channel estimation; error statistics; frequency division multiple access; interpolation; least squares approximations; mean square error methods; mobile radio; 802.16-2005; Doppler frequencies; Mobile WiMAX Systems; OFDM symbol; OFDMA; bit error rate; channel tracking; downlink channel estimation; high-speed, broadband fixed services; interpolation; least square methods; mean square error; mobile communications; mobile services; orthogonal frequency division multiple access; Bit error rate; Channel estimation; Downlink; Fading; Frequency conversion; Frequency estimation; Mobile communication; OFDM; System performance; WiMAX;
Conference_Titel :
Computer and Communication Engineering, 2008. ICCCE 2008. International Conference on
Conference_Location :
Kuala Lumpur
Print_ISBN :
978-1-4244-1691-2
Electronic_ISBN :
978-1-4244-1692-9
DOI :
10.1109/ICCCE.2008.4580823
