分频段数字音频动态范围处理器的设计、仿真与测试

本文提出一种分频段数字音频动态范围处理器的设计方法。传统的分频段方法主要采用滤波器组，而本文则利用扬声系统中的LR分割器来分割频段。传统的动态范围处理器通常利用前馈包络法和低通滤波器来平滑增益曲线。但面对快速变化的信号或噪声，此类方法得到的结果可能会有较大的失真。针对此问题，本文提出了一种创新的时间幅度并行控制法，在时间和幅度域内同时对信号进行控制，能很好地降低噪声并改善输出信号的失真度。最后，本文给出了MATLAB仿真和基于ADSP21364的实测结果，验证了本方法的性能。 

Design,Simulation and Measurement of Split-band Digital Audio Dynamics Processor

A new method of split-band audio dynamics processor is proposed. Traditionally, band splitting is realized with filter banks. In this paper, we use the LR crossover in loudspeaker system to split the audio spectrum. The feed-forward envelope detection and low-pass filters are usually employed to smooth the gain curve and control the dynamic range of the signal. But these methods may suffer large distortion when facing rapidly-changing signal or noise. To solve this problem, we propose a new parallel control method both in time and amplitude domain, which can reduce the noise and distortion. The results of MATLAB simulation and measurement on ADSP21364 are provided to verify the advantage and efficiency of the proposed method finally.