SSB modulation with dynamic carrier control and n-order distortion compensation for micro audio directional system

SSB modulation method with both dynamic carrier control and n-order distortion compensation is investigated to realize low power consumption and high fidelity for micro audio directional system. The fundamental signal processing method of audio directional system is clarified with the review of Berktay's far-field solution. With the general SSB modulation analysed on the harmonic distortion and output power, a dynamic carrier control system is proposed to control the dissipation of power consumption. A n-order compensation method is developed to reduce the distortion. With dynamic control law of √x and 1-order compensation, the modulating algorithm is realized on a prototype of micro audio directional loudspeaker. The intermodulation distortion and power consumption are measured compared with the general SSB modulation. The results indicates that the distortion and the power consumption are reduced drastically. It is demonstrated experimentally that the signal processing algorithm proposed in the paper is feasible for utilizing in micro audio directional system.