Method and apparatus for driving digital loudspeaker based on amplitude modulation and phase modulation

Abstract

The present invention discloses a method and an apparatus for driving a digital loudspeaker based on amplitude modulation and phase modulation. The method comprises the steps of: performing modulation processing for a sound source signal to generate (2L+1) coded signals x at a level grade; performing selection processing for the coded signals x and a feedback vector signal b of M channels to generate a state vector signal s of the M channels, and then performing amplitude modulation processing for the state vector signal s to generate an amplitude modulation vector signal a of the M channels; performing shaping processing for the amplitude modulation vector signal a to generate a next feedback vector signal b of the M channels; performing phase modulation processing for the state vector signal s to generate a driving vector signal p of the M channels; and achieving electro-acoustic conversion of the driving vector signal p through a power amplification driving multichannel power amplifier and energy transducer unit. The method and the apparatus of the present invention can simultaneously adjust amplitudes and phases of various channels, thereby achieving better spatial domain directivity.

Description

technical field [0001] The present invention relates to a digital loudspeaker driving method and device, in particular to a digital loudspeaker driving method and device based on amplitude modulation and phase modulation. Background technique [0002] With the rapid development of VLSI manufacturing technology, the design and manufacture of loudspeaker systems, the leading product in the electro-acoustic industry, are gradually developing in the direction of low power consumption, miniaturization, and portability. In recent years, the semi-digital loudspeaker system driven by the wave of digitalization has successfully solved the power consumption and heat generation problems due to its use of Pulse Width Modulation (PWM) Class D power amplifier drive technology, and greatly improved the overall The electroacoustic conversion efficiency of the system. However, the rear stage of the semi-digital loudspeaker system still needs to rely on a bulky LC low-pass analog filter to f...

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Problems solved by technology

There are two main defects of this method: (1), dividing the original pulse into N small pulses of equal width will further increase the clock sampling frequency, which will break through the upper limit of the switching rate of the power switch tube, thus making the switch The tube is in a saturated state, which introduces nonlinear distortion and reduces the signal quality; (2) There are restrictions on the magnitude of the amplitude coefficient. First, the amplitude coefficient cannot be too large, otherwise the distortion of the switching tube will be too large. Secondly, the amplitude coefficient can only be an integer, which cannot be realized. Arbitrary amplitude phase modulation, so this method is not applicable in practice

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