Efficient adaptive loading algorithm with simplified bandwidth optimization method for OFDM systems

A crucial aspect for adaptive bit and power loading algorithms is to determine all usable subchannels. In this paper, a simplified bandwidth optimization method is proposed to search for all usable subchannels for loading algorithms which aim at the minimization of power consumption with constraint of constant data rate and target bit error rate (BER). Based on this method, an efficient loading algorithm is developed. Simulation results show that the proposed algorithm can achieve the same bit allocation results to that of the well-known Hughes-Hartogs and Fischer et al. algorithm. This algorithm is appropriate for OFDM systems in time-varying channels due to its low complexity.