Performance of the OFDM based adaptive modulation system with a multilevel transmit power control scheme using delay profile extrapolation technique for high mobility terminals

摘要

This paper proposes an orthogonal frequency division multiplexing (OFDM) based adaptive modulation system (AMS) with a multilevel transmit power control (MTPC) using delay profile extrapolation technique to achieve high quality broadband wireless transmission for high mobility terminals. In the proposed system, delay profile information (DPI) that is important to know the received signal level for each subcarrier is estimated by linearly extrapolating the preciously received DPI sequence to improve tracking ability of OFDM AMS and 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 can achieve high quality data transmission for high mobility terminals.