Design Of Voice Gateway In Coalmine Communication System

The occasional coal mine accidents bring huge loss of personnel and property.Based on the analysis of the most widely used voice communication system, thisthesis proposes a solution of accessing the underground CAN bus and RS-485busbroadcasting system to the Ethernet uniformly via voice gateway to avoid or minimizethe accident damage. The broadcast system can initiate emergency broadcast call overthe whole network and guide workers to get away from dangers scientifically duringthe accidents. It is also a helpful to the daily management of the coal mine.According to the current application situation of coal mine voice communicationsystem, the design scheme of voice gateway and both its software and hardware aregiven in this thesis. Considering the characteristics of the application environment, theecho cancellation technique combined with silence detection is added to the gateway,in order to improve the quality of voice communication and save the preciousbandwidth resource. In silence detection technology, the detection algorithm based onenergy is improved to achieve the purpose of saving bandwidth. In the aspect of echocancellation, in order to realize the detection of double talk state, double-talkdetection based on GEIGEL is introduced for the judgment of double-talk state, andthe adaptive filter is modified to improve the quality and real-time of the voicecommunication. Finally, the system is simulated and analyzed its performance byMATLAB. The effects of echo cancellation on system performance are obtained andthe results show that the system can indeed save bandwidth and improve the quality ofvoice communication system in application. Besides the storage method is optimized.