Adaptive sub-carriers control scheme for OFDM cellular systems

This paper proposes a control scheme that can achieve high bit rate transmission and high system capacity in the OFDM cellular system. The proposed system controls a transmitting rate of each user by selecting the number of available OFDM sub-carriers according to the traffic conditions adaptively. When the traffic is low, the proposed system can achieve high bit rate transmission with larger number of sub-carriers. On the other hand, when traffic is high, the proposed system can prevent service quality degradation due to interference among users by using fewer sub-carriers and conducting TDM transmission. Computer simulation confirms that the proposed system can achieve high capacity without degrading service quality.