Research And Design Of Real-time Network Audio Distribution Unit

With the popularity and development of network, especially the development of Ethernet, high-quality-multiple-channel audio transmission is the basic demand for the broadcast industry, big stadium, high building broadcast, and big entertainment place. The traditional analog transmission can not satisfy the modern broadcast need. Transmitting audio digitally over the network becomes the developing trend.The design of the network real-time audio transmission unit is to transmit the audio over the network. First, it converts the sampling analog signal to digital signal. FPGA harmonizes the interoperation of all modules. Finally the digital signal processing unit compresses the audio to standard Ethernet messages, which are transmitted to the receiving device. So the design can achieve the real-time audio transmission. And my work is as follows.(1)The digital network audio processor is studied. And network audio tansmission suit scheme is adopted, which is consisted of multiple audio transmission devices. According to signal processing modules, the dissertation adopted the function achievement, modulized design is easy to realize.(2) Hardware modules are designed, including digital audio processor, Ethernet controller, Flash, multiple-channel audio importing module, exporting modole, LED mutiple-channel audio supervision module. First, the digital audio processing combined with Ethernet controller and Flash can achieve compressing the audio to standard Ethernet messages, which are transmitted to the receiving device and uncompressed to the audio signal. Then the dissertation mainly studies the audio importing and exporting modules.(3) FPGA implements the port input of digital signal processing unit,A/D calibration, D/A mute etc. Routing 16-channel audio, converting the stero audio to single channel audio, convertting IIS audio to 24 bit parallel data, and comparing audio status through VHDL program are to achieve multiple-channel audio intensity display.To sum up, the dissertation achieves the fuctions of the high-quality audio transmission and multiple-channel audio supervision by the interaction of audio importing modules, digital signal processing unit, audio exporting modules and FPGA multiple-channel audio supervision circuit. Modularized software and hardware design is useful to the secondly development, easily be used in all kinds of situation. The whole design achieves the design requirement.