本文選題：鐵路 + 應(yīng)急通信��； 參考：《天津大學(xué)》2014年碩士論文

【摘要】：鐵路應(yīng)急通信系統(tǒng)走過(guò)了30多年的發(fā)展道路，為鐵路搶險(xiǎn)指揮提供了有效保障。高速鐵路和客運(yùn)專線建設(shè)的不斷提速，鐵路改革的不斷深入，對(duì)鐵路應(yīng)急通信提出了新的要求。現(xiàn)有單一應(yīng)急指揮中心與應(yīng)急現(xiàn)場(chǎng)的應(yīng)用模式已不能滿足鐵路應(yīng)急事件搶險(xiǎn)的需求，急需升級(jí)為多中心應(yīng)急指揮系統(tǒng)。作者承擔(dān)的鐵路總公司、若干鐵路局調(diào)度指揮中心通信工程設(shè)計(jì)中，都有升級(jí)改造現(xiàn)有應(yīng)急通信系統(tǒng)的需求。通過(guò)對(duì)鐵路應(yīng)急通信系統(tǒng)新需求和升級(jí)方案的研究得知，，實(shí)現(xiàn)多中心通信功能的技術(shù)難題是聲音信號(hào)的混音，實(shí)現(xiàn)混音有兩個(gè)關(guān)鍵技術(shù)——重采樣算法和混音算法。 文中首先對(duì)音頻信號(hào)處理、傳輸、交換過(guò)程中的幾個(gè)關(guān)鍵概念和技術(shù)進(jìn)行了簡(jiǎn)單的介紹，如聲波、混音、VoIP、軟交換、SIP協(xié)議、RTP協(xié)議等。其次，通過(guò)對(duì)音頻信號(hào)數(shù)字化過(guò)程的分析和計(jì)算機(jī)中音頻信號(hào)WAVE格式的分析，提出了音頻重采樣的線性算法、多項(xiàng)式算法，分析了兩種算法的優(yōu)缺點(diǎn)，確定了參數(shù)選擇，通過(guò)計(jì)算機(jī)編程實(shí)現(xiàn)了多項(xiàng)式重采樣算法并對(duì)結(jié)果進(jìn)行了驗(yàn)證。再次，對(duì)常用的微軟DirectSound環(huán)境進(jìn)行了詳細(xì)的分析，找出了其在鐵路應(yīng)急通信系統(tǒng)中難以使用的原因。根據(jù)DirectSound的設(shè)計(jì)思路研究了新的混音算法，對(duì)線性混音、限幅混音、平均混音和權(quán)重混音算法進(jìn)行了效果分析、模擬試驗(yàn)，確定了權(quán)重混音作為推薦算法，通過(guò)編程實(shí)現(xiàn)權(quán)重混音算法并在實(shí)驗(yàn)環(huán)境下進(jìn)行了驗(yàn)證。最后，介紹了多中心應(yīng)急通信系統(tǒng)的設(shè)計(jì)過(guò)程，對(duì)混音處理模式進(jìn)行了方案比選，確定了系統(tǒng)總體架構(gòu)，具體研究了多中心鐵路應(yīng)急系統(tǒng)實(shí)現(xiàn)的內(nèi)容并進(jìn)行了模擬測(cè)試，達(dá)到了研究的預(yù)期目的，為實(shí)現(xiàn)多中心多用戶通話組的混音功能提供了理論和技術(shù)支持。
[Abstract]:Railway emergency communication system has been developed for more than 30 years, which provides an effective guarantee for railway emergency command. With the rapid construction of high-speed railway and passenger dedicated line and the deepening of railway reform, new requirements are put forward for railway emergency communication. The existing application mode of single emergency command center and emergency scene can no longer meet the needs of railway emergency response and need to be upgraded to multi-center emergency command system. In the communication engineering design of the dispatching and command center of several railway bureaus, the author has the need to upgrade and transform the existing emergency communication system. Through the research on the new requirement and upgrade scheme of railway emergency communication system, it is known that the technical problem to realize the multi-center communication function is the mixing of sound signal, and there are two key technologies to realize the mixing: resampling algorithm and mixing algorithm. In this paper, several key concepts and techniques in audio signal processing, transmission and switching are introduced, such as acoustic wave, VoIP, SIP protocol and RTP protocol. Secondly, through the analysis of the digitization process of audio signal and the analysis of wave format of audio signal in computer, the linear algorithm and polynomial algorithm of audio resampling are put forward, and the advantages and disadvantages of the two algorithms are analyzed, and the selection of parameters is determined. The polynomial resampling algorithm is realized by computer programming and the result is verified. Thirdly, the Microsoft DirectSound environment is analyzed in detail, and the reason why it is difficult to use in railway emergency communication system is found out. According to the design idea of DirectSound, a new mixing algorithm is studied, and the effects of linear mixing, amplitude limiting mixing, average mixing and weight mixing are analyzed, and the simulation results show that the weighted mixing is the recommended algorithm. The weight mixing algorithm is realized by programming and verified in the experimental environment. Finally, the design process of the multi-center emergency communication system is introduced, the scheme of mixing processing mode is compared and selected, the overall structure of the system is determined, and the contents of the multi-center railway emergency system are studied and simulated. It provides theoretical and technical support for the realization of the mixing function of multi-center multi-user call groups.
【學(xué)位授予單位】：天津大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2014
【分類號(hào)】：TN914

【參考文獻(xiàn)】

相關(guān)期刊論文 前1條

1 黎劍兵,李永強(qiáng),徐敏;基于DirectSound的混音與放音實(shí)現(xiàn)[J];電子科技;2004年03期

本文編號(hào)：2078651