Design And Implementation Of Front-End Interface Board For Multi-Microphone Audio DSP Chip Assessment Platform

With rapid development of mobile communication technology and the emergence of smart phone, new technology and application have put higher requirements on audio frequency processing of mobile phone. This thesis, in view of test requirement of audio frequency chip of multiple microphones mobile phone, with purpose of measuring objective index of voice and audio frequency, combining microphone array technology and multiple microphones voice enhancement algorithm, designs and realizes the front end interface board of audio frequency test platform.This thesis, according to test requirement of beam forming characteristic of multiple microphones, studies the hardware and software realization program of front end interface board, and designs the hardware circuit composed of multiple embedded processors. This thesis also analyses the USB audio frequency protocol, designs the USB descriptor and callback function on embedded processor; analyses the effect on beam forming test result exerted by audio stream time delay, and designs synchronization program for multiple channels audio stream.Main function of the interface board is format conversion and signal synchronization for USB audio equipment and audio data. According to requirement, functions of descriptor and recording and playing of USB audio equipment are realized, and conversion from USB audio format to DSP audio format is realized. Besides, by analyzing the effect on beam forming test result exerted by audio stream time delay, multiple channels audio stream synchronization is realized.This thesis tests the function of the interface board, and test result shows that its function meets the preset design requirement. At last, complete audio test platform composed of the front end interface board and back end host tests the audio frequency index of multiple microphones DSP chip, which gets the audio performance index such as voice quality, noise inhibition, beam forming etc.This thesis treats of the realization of the front end interface board with characteristics of low cost, multiple channels supporting and DSP audio frequency format output, which has great significance in the market.