Sub-band rate and power control for wireless OFDM systems

Adaptive resource allocation with water-filling has been considered to be an efficient way of increasing data throughput for multicarrier systems. However, the water-filling technique usually requires perfect channel state information; thus, its application is very limited in wireless environments where only partial channel knowledge is available at the transmitter. A sub-band rate and power control algorithm is proposed as a sub-optimal scheme of resource allocation for wireless OFDM systems. We analyze the effect of Doppler frequency in the sub-band rate and power control algorithm and show the capacity increase with the proposed algorithm. We also extend the algorithm to multiuser cases. For both single and multiuser cases, the rate and power control is evaluated in two senses: ergodic capacity and outage probability.