A delay profile information based subcarrier power control combined with a partial non-power allocation technique for OFDM/FDD systems

This paper proposes a delay profile information based subcarrier power control combined with a partial non-power allocation technique for OFDM/FDD systems to achieve high bit-rate and high quality non-voice data transmission for wireless communication systems. To improve the bit error rate (BER) performances for the convolutionally encoded OFDM system, the proposed system controls the transmit power for each subcarrier in order to keep the received power of each subcarrier constant using a measured delay profile and noise level given by a delay profile information (DPI) channel in the return-link. To further reduce the transmit power needed to achieve high quality data transmission, a partial non-power allocation (PNPA) scheme combined with a punctured coding technique is further applied to the subcarrier power control. In this scheme, the deleted bits by the punctured coding are allocated to the nonreliable subcarriers and transmit power for these subcarriers are power-suppressed. Computer simulation confirms that the proposed system can achieve high quality data transmission and reduction of transmit power as compared with that of a conventional system in frequency selective fading environments