A study on adaptive uplink resource control scheme for asymmetric packet radio communication systems using OFDMA/TDD technique

摘要

This paper proposes an orthogonal frequency division multiple access/time division duplex (OFDMA/TDD) packet transmission system with an adaptive resource control scheme to support wireless multimedia communication services. In the proposed scheme. spectral resource ratio between uplink and downlink is adaptively controlled according to the uplink traffic load estimated by the ratio of used to unused subcarriers at the base station. Moreover, the proposed system copes with dynamical traffic variation by changing the flame format, coding rate and transmit power in the OFDMA/TDD system. For suppression of inter-subchannel interference, packet-switching based transmission is employed in the uplink. Computer simulation confirms that the proposed system achieves good average delay performances.