A Hughes-Hartogs Algorithm Based Bit Loading Algorithm for OFDM Systems

This paper proposes a bit loading algorithm for orthogonal frequency division multiplexing (OFDM) systems. With the restrictions of available transmit power and required bit-error-rate (BER) performance, the algorithm aims at achieving the maximal data rate. Although the proposed algorithm is based on the Hughes-hartogs algorithm, the computational complexity is only $O(k \times M)$,where k denotes the number of iterations required to meet the constraints and M denotes the number of subcarriers. Simulation results show that $15$ iterations are sufficient to meet the constrains, and the degradation of information bits loaded per OFDM symbol is less than one percent over the entire available transmit power. The proposed algorithm is appropriate for practical OFDM systems with either uniform or different SNR gaps in wireless channels for its low computational complexity and good performance.