Simple bit loading algorithms for OFDM-based systems with limited feedback

In this paper, we give low complexity bit loading algorithms with limited feedback for an Orthogonal Frequency Division Multiplexing (OFDM) system. We propose to simplify the incremental bit loading algorithm by turning off the subcarriers having a weak Signal to Noise Ratio (SNR) before applying the algorithm. We also propose to divide the subcarriers into groups to further simplify the bit loading algorithm and decrease the number of feedback bits. We emphasize that there are two methods to return the bit allocation from the receiver to the transmitter and precise which method minimizes the number of feedback bits. Simulations show that our proposed algorithms present close results in terms of the data throughput and give significant gains in terms of the computation time compared with the incremental algorithm.