High bit rate transmission scheme with a multilevel transmit power control for the OFDM based adaptive modulation systems

This paper proposes a multilevel transmit power control (MTPC) for OFDM based adaptive modulation systems (OFDM AMS) to achieve high bit rate transmission services without increasing the transmit power. In the proposed system the modulation level for each subcarrier is controlled according to the channel conditions. Moreover to further increase average bit rate, the proposed system employs a multilevel transmit power control (MTPC) in which the modulation level and transmit power for each subcarrier is controlled to maximize transmitted bits per OFDM symbol while keeping its transmit power constant using a conventional transmit power control (TPC) technique. Computer simulation confirms that the proposed system is effective in achieving higher bit rate transmission without increasing its transmit power