Effects on the Performance of Parametric Loudspeaker Caused by Nonideal Ultrasound Transducer

Abstract

In this paper, we report the effects on the performance of a parametric loudspeaker caused by a nonideal ultrasound transducer. The frequency contents of self-demodulated secondary wave pressure for the nonideal ultrasound transducer are first derived on the basis of Berktay's solution. Then, according to the relationship between the input signal and the envelope of primary wave pressure, the harmonic distortion and intermodulation distortion are obtained for different modulation techniques. Simulation experiments show that in the case of using the double-sideband amplitude modulation (DSB-AM) technique, the amplitudes of the fundamental frequency and intermodulation distortion components are affected by both the phase and magnitude response of the ultrasound transducer, whereas the harmonic distortion component is only affected by the phase response. In the case of using the single-sideband amplitude modulation (SSB-AM) technique, the amplitudes of the fundamental frequency component and intermodulation distortion components are only affected by the magnitude response of the transducer.

An efficient subcarrier arrangement for airborne OFDM communication using parametric loudspeaker

“…It is known that not only the fundamental sound but also the second harmonic sound occurs. [23][24][25][26][27][28][29] On the basic of the principle the parametric loudspeakers produce secondary nonlinear components, we propose an efficient subcarrier arrangement for OFDM communication using parametric loudspeakers that do not cause inter-carrier interference (ICI) even if the secondary nonlinear component occurs. Specifically, we consider two subcarrier arrangement designs: odd-comb OFDM and narrow-band OFDM.…”

Digital acoustic communication in air using parametric loudspeaker

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