A power-efficient resource allocation scheme for multiuser OFDM

We present a new power-efficient resource allocation scheme for downlink multiple access communications based on OFDM for indoor wireless systems. A theoretical bound on the minimum total transmit power at the base station while satisfying the bit-rate (BR) and bit-error rate (BER) criterion of the various portable users in the system is derived. As this cannot be realized in a simple manner, we present a new method for allocating subcarriers, modulation mode, and power to the signals transmitted to the different users. We present simulation results comparing the performance of our algorithm with an OFDM-TDMA system. The effect of frequency-domain correlation on the performance is also presented. We have considered an indoor wireless system with a quasi-static fading channel for our simulations. The new algorithm achieves a gain of about 3 dB over the OFDM-TDMA scheme.