振幅调制-非线性调频信号测量声场的脉冲响应

提出采用振幅调制-非线性调频（AM-NLFM）信号测量声场的脉冲响应，AM—NLFM信号基于相位驻留原理的调制方法．该信号在测量声场脉冲响应时，具有良好的抗系统非线性失真和时变影响的能力，可以降低非周期傅里叶变换时的频谱泄漏，且可以根据任意频谱调制而能保持很低的波峰因数．实测表明该信号可以有效提高脉冲响应测量的速度与精度．该信号也可用于电声系统传递函数的测量中．

Impulse Response Measurement of Sound Fields with AM-NLFM Signal

Amplitude modulation and nonlinear frequency modulation(AM-NLFM) is proposed as excitation signal to measure impulse response of sound field.The modulation method of the signal is introduced on the basis of the stationary phase principle.Immunity against system nonlinearly distortion and time variance can be improved significantly with the signal.Also it can minimize leakage errors involved in fast fourier transform(FFT) based measurement and can be pre-emphasized by keeping low crest factor.The practical measurements show that the measurement speed and accuracy can be efficiently improved with the signal as excitation signal,which can also be used in transfer-function measurement in audio system.