Sound quality and transmission characteristic improvement for acoustic OFDM

In this paper, we propose a novel method to embed information data on DCT(Discrete Cosine Transform) domain and control transmission power of each sub-carrier using frequency masking for acoustic OFDM(Orthogonal Frequency Division Multiplex) in order to improve the sound quality and the transmission characteristic. In the acoustic OFDM, information data is placed on the phase of each sub-carrier, so that the sound quality deteriorates as the transmission rate increases. Moreover, sub-carriers with low electric power deteriorate the whole transmission characteristic due to additive noise because the frequency spectrum of audio signal is not flat. We therefore propose an embedding method using DCT for the deterioration of the sound quality and a power control method using frequency masking for the deterioration of the transmission characteristic. Moreover, we demonstrate that the combination of the proposed methods can simultaneously realize an increased transmission rate and an improved sound quality through some simulation results.