Research And Application Of Intranet Digital Audio Broadcast Platform

Audio signals can be transmitted conveniently from one terminal to another by the traditional analogue audio broadcast technology.However,it will meet a series of problems to transmit audio signals in a large-scale broadcast system.Firstly,the audio signal quality, including signal-to-noise ratio and high-frequency response characteristics,will decline sharply with the increase in transmission distance.Secondly,due to the existence of huge modern buildings,how to reduce the wiring cost and decrease the signal attenuation in analogue audio broadcast system is a troublesome problem.Thirdly,it is difficult to realize some new functions, such as packet broadcast,fault location,system redundancy and so on.With the development of the Intranet real-time application technology,the traditional analogue audio broadcast technology will be replaced by the IDBP technique gradually.In this paper,based on the analysis of CobraNet and EtherSound audio broadcast technology,we introduced a kind of Intranet Digital Broadcast Platform(IDBP) with independent intellectual property rights,which is suitable for the audio public broadcast with low requirement of real-time characteristics.The main work and the results are as follows:1.The technical proposal of IDBP is introduced.The primary techniques include: low-delayed intranet audio data communication scheme,advanced adaptive jitter buffering control algorithm,applicable IDBP protocol,high-performance digital audio compression scheme,systematic architecture and redundancy backup.2.Based on the IDBP technique,a suit of demonstrating prototype is built.A kind of audio server control software with independent intellectual property rights is designed,and the terminal equipment of IDBP and real-time audio data sampling based on the NiosⅡsoft core embedded processor andμC/OS-Ⅱreal-time operating system are developed.3.The software design of terminal equipment based onμC/OS-Ⅱreal-time operating system,HAL(Hardware Abstraction Layer) library and LwlP(Lightweight IP) protocol is introduced in detail,and the hardware design of terminal equipment based on SOPC(System on Programmable Chip) technique is described.Due to the online update of the hardware/software design and the independent intellectual property rights,the industrial application of the technique is prospective.4.The functions of the designed IDBP system include:all the functions of traditional broadcast system,dynamic partition broadcast,real-time intercut broadcast,mobile broadcast, remote management,real-time monitoring.