Research And Design Of A Centralized Digital Audio Matrix

As digital signal processing technology and network technology continuouslyintegrate into audio technology, large halls, radio stations, entertainment places, airports,and railway stations raise stricter requirement to audio technology. Traditional analogaudio system can hardly meet the demands of modern construction. Digitization andnetworking will be an inevitable trend of the development of audio technology. As animportant equipment to build a large-scale audio system, digital audio matrix is widelyused in audio signal processing, distribution and transmission. Its performance willdirectly affect whether the audio system can normally work, and its stability also playsan important role to the reliability of entire audio system.The digital audio matrix designed in this paper is a new kind of audio matrix,which is built based on double-star-bus structure. The digital audio matrix consists of2master modules,15IO processing modules and back-plane which connects mastermodules and IO processing modules. This two modules connects in double-star-busstructure, avoiding the disadvantage of TDM centralized audio matrix excessivedependence on the Switching-Bus, enhances the security and stability of audio matrix.In this paper, we will realize some related improvement and design, against theshortcomings and deficiencies of the existing audio conversion module and audioprocessing module. The mainly contents of this thesis are as following:1. The structure design of star-bus and double-star topology, and the analysis ofthe function of three modules in this structure.2. The design and analysis of the protocol used in the digital audio matrix.3. The improvement and design of the audio conversion module. We mainlyfocuses on breaking the dependence of AES3digital audio converter module’s workingclock to AES3input signal. Our purpose is making the conversion free between IISstereo audio and AES3professional digital audio. By the way, we design anotherCobraNet network audio conversion module, which makes our Digital Audio Matrixsupport the interface of network audio.4. The improvement and design of audio processing modules. In this section, we mainly improve the capability of DSP processing source audio, including theequalization, gain and limitation of8-channel audio signals, and the mixing of4-channel stereo signals. In addition, we also develop the capability of monitoring theamplitude and phase of the audio signal in Digital Audio Matrix. This function enablesusers to monitor the quality of the audio signal in visual perspective directly.The improved Digital Audio Matrix develops a new CobraNet network audiointerface, and it also has a better support to the AES3digital audio signal interface. Bythe way, its ability of processing digital audio signal and monitoring audio quality havebeen greatly improved.