Symbol-by-Symbol Based Multilevel Transmit Power Control for OFDM Based Adaptive Modulation under High Mobility Terminal Conditions

Tomoaki YOSHIKI  Seiichi SAMPEI  Norihiko MORINAGA  

IEICE TRANSACTIONS on Communications   Vol.E86-B   No.1   pp.230-237
Publication Date: 2003/01/01
Online ISSN: 
Print ISSN: 0916-8516
Type of Manuscript: Special Section PAPER (Special Issue on Multiple Access and Signal Transmission Techniques for Future Mobile Communications)
OFDM,  adaptive modulation system,  high mobility,  extrapolation,  space diversity,  

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This paper proposes a symbol-by-symbol-based multilevel transmit power control (MTPC) scheme for orthogonal frequency division multiplexing (OFDM) based adaptive modulation system (AMS) to achieve high quality broadband wireless transmission for high mobility terminals. In the proposed system, delay profile for each OFDM symbol is estimated by linearly extrapolating previously received delay profile information (DPI) sequence to improve tracking ability of OFDM based AMS with MTPC to the fast fading variation. Moreover, 2-branch reception diversity is applied to reduce dynamic range and variation speed of the multipath fading. Computer simulation confirms that the proposed system is effective in supporting higher mobility terminals with keeping high transmission quality.