Computationally efficient implementation of recursive single-sideband amplitude modulation modulation for parametric loudspeaker

Modulation techniques play an important role on the performance of parametric loudspeaker. One of the most popular among them is the recursive single-sideband amplitude modulation (SSB-AM) technique due to its low distortion and bandwidth requirement. The recursive SSB-AM modulation consists of two basic parts: the Hilbert filter and the equalization filter. Usually, these two parts operate at a sample rate several times higher than the carrier frequency, which incurs a heavy computational load. In this paper, a novel implementation of the recursive SSB-AM technique is proposed. Simulations showed that the computational load is significantly reduced by the proposed implementation without any performance degradation.