在嵌入式Blackfin平台實作網路語音交換機之回音消除

Implementation of IP-PBX Echo Cancellation on Embedded Blackfin Platform

陳俊仁(Chun-Jen Chen)

指導教授 ： 李清坤

大同大學/電機資訊學院/通訊工程研究所/碩士(2012年)

摘要

電話用戶交換機的市場已逐漸從傳統分時多工(Time-Division Multiplexing, TDM)技術朝向由網路傳輸SIP語音協定的網路語音交換機開發。網路語音交換機比傳統交換機的優勢為透過網路語音傳輸可節省高額的跨國通信費用，硬體設備也利用遠端網路連接方式降低支出。
本篇論文使用Analog Device公司的Blackfin系列晶片BF533平台，建立一套開放式網路語音交換機軟體Asterisk並使用SiliconLABs公司的FXO/FXS晶片建構一套完整的網路語音交換機(IP-PBX)。本論文研究重點是模擬使用在公眾電話網路上Asterisk IP-PBX的回音消除處理效果分析。

關鍵字

網路交換機 ； 回音消除

並列摘要

The technology trend of private branch exchange (PBX) for telephony communication has gradually shifted from the traditional time-division multiplexing (TDM) technology toward session initiation protocol (SIP) voice protocol by the network transmission on internet. The advantages of internet voice PBX is not only in the huge cost saving of international communication, but also the reduction of spending in hardware network and remote control investment.
In this thesis, we use the Blackfin series chip BF533 platform provided by the Analog Device to build the Asterisk open source software for internet voice PBX and apply the SiliconLABs FXO/FXS chip solution to construct a complete set of IP-PBX system. The research of this thesis focuses on the simulation and analysis of the echo cancellation effect on the Asterisk IP-PBX in the public switched telephone network (PSTN).

並列關鍵字

echo cancellation ； blackfin ； asterisk ； IP-PBX

參考文獻

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[3] S.Goel and M.Bhattacharya, ”Speech Based Dialog Query System over Asterisk PBX server,” in Proc. IEEE International Conference on Signal Processing (ICSP), 2010.

[9] Cisco, ”Echo Analysis for Voice over IP,” 2002.

[12] 邵世祥,聲學回音消除於免持式網路電話之分析研究,大同大學通訊工程研究所碩士論文,2010.

[13] K. Ochiai, T. Araseki and T. Ogihara, ”Echo Canceler with two echo path models,” IEEE Trans. on Commun., vol.25, pp. 589-595, 1977.