【摘要】：隨著手機(jī)通信的不斷發(fā)展,一個新的“手機(jī)電視”概念隨之產(chǎn)生。國外的ISDB-T、DVB-H、MediaFLO、DMB手機(jī)電視標(biāo)準(zhǔn)逐漸成熟并投入商業(yè)運(yùn)營。作為我國自主研發(fā),具有完全知識產(chǎn)權(quán)的移動多媒體廣播(CMMB, China Mobile Multimedia Broadcast)標(biāo)準(zhǔn)也正式成立,并投入到建設(shè)運(yùn)營中。移動多媒體廣播以UHF頻段的信號覆蓋地面,作為一種新興的無線廣播技術(shù),如何進(jìn)行信號覆蓋,如何解決覆蓋中所遇到的一些問題,是本文重點研究的對象。 文章中介紹了電磁波的分類、信道環(huán)境分類、信號損耗分類。電磁波的分類是根據(jù)電磁波經(jīng)過不同路徑到達(dá)終點所區(qū)分的。傳播信道的分類則是根據(jù)不同的地理環(huán)境,經(jīng)過概率學(xué)計算得出的數(shù)學(xué)模型。信號損耗分類體現(xiàn)了電磁波在不同情況下的功率損耗的特性。論文中還著重介紹了OFDM、保護(hù)間隔、信道編碼、同步技術(shù),這些技術(shù)是CMMB的關(guān)鍵組成部分。以上知識為CMMB的無線覆蓋提供了理論依據(jù)。 作為本文的研究對象,CMMB的無線覆蓋是重點探討的問題。首先,介紹了CMMB的網(wǎng)絡(luò)架構(gòu),解釋了信號由衛(wèi)星傳輸至地面,再由發(fā)射機(jī)發(fā)射至移動終端上的過程。根據(jù)技術(shù)標(biāo)準(zhǔn)和工程實踐經(jīng)驗,歸納總結(jié)了CMMB的三種覆蓋方式,分別是單發(fā)射臺站、單頻網(wǎng)、信號補(bǔ)盲。文中針對這三種覆蓋方式,從概念、適用范圍、原理等多方面進(jìn)行分析。單頻網(wǎng)作為一種CMMB無線覆蓋的重要的方式,文中提出了同頻干擾、保護(hù)間隔等概念,通過OFDM中信道編碼的特性,計算出兩個發(fā)射機(jī)臺站之間的間隔不得超過15.36公里,否則兩個發(fā)射機(jī)臺站之間的區(qū)域必定會產(chǎn)生同頻干擾。 其次,通過對本人主持和參與的兩項CMMB工程,對上述無線覆蓋相關(guān)理論和設(shè)計方法進(jìn)行應(yīng)用和驗證。通過南昌市單頻網(wǎng)的網(wǎng)絡(luò)仿真計算來判斷規(guī)劃是否可行,根據(jù)仿真結(jié)果發(fā)現(xiàn)存在有效覆蓋范圍減少、同頻干擾、時間不同步、頻率不同步等問題,根據(jù)理論知識和實踐經(jīng)驗針對這些問題分別提出了解決辦法。上海市虹橋樞紐西航站樓室內(nèi)分布系統(tǒng)包含了CMMB和GSM、CDMA、WLAN、WCDMA等多種通信信號的覆蓋,從這個設(shè)計實例中可以歸納CMMB與其他系統(tǒng)之間的合路設(shè)計思路及方式,為將來CMMB更多的與其他信號合路共建室內(nèi)分布系統(tǒng)提供了參考。 最后,總結(jié)了論文的結(jié)構(gòu)和研究對象,并提出了CMMB無線覆蓋中需要進(jìn)一步研究的方向和思路。
[Abstract]:With the development of mobile phone communication, a new concept of mobile TV has come into being. ISDB-T,DVB-H,MediaFLO,DMB mobile TV standards abroad gradually mature and put into commercial operation. As an independent R & D, mobile multimedia broadcasting (CMMB, China Mobile Multimedia Broadcast) standard with full intellectual property rights has been established and put into construction and operation. Mobile multimedia broadcasting covers the ground with the signal of UHF band. As a new wireless broadcast technology, how to cover the signal and how to solve some problems encountered in the coverage are the main research objects of this paper. In this paper, the classification of electromagnetic wave, channel environment and signal loss are introduced. The classification of electromagnetic waves is based on the electromagnetic waves passing through different paths to the end point. The classification of propagation channel is a mathematical model based on different geographical environment and probabilistic calculation. Signal loss classification reflects the characteristics of electromagnetic wave power loss under different conditions. In this paper, OFDM, protection interval, channel coding and synchronization techniques are also introduced, which are the key components of CMMB. The above knowledge provides a theoretical basis for wireless coverage of CMMB. As the object of this paper, the wireless coverage of CMMB is an important issue. Firstly, the network architecture of CMMB is introduced, and the process of signal transmission from satellite to ground and then from transmitter to mobile terminal is explained. According to the technical standard and engineering practice, three coverage modes of CMMB are summarized, which are single transmitter station, single frequency network and signal blind compensation. In this paper, the concept, scope of application, principle and other aspects of the three coverage methods are analyzed. As an important way of CMMB wireless coverage, the concepts of co-frequency interference and protection interval are put forward in this paper. Through the characteristic of channel coding in OFDM, the distance between two transmitter stations is calculated not to exceed 15.36km. Otherwise, the area between the two transmitter stations must produce the same frequency interference. Secondly, the above theories and design methods of wireless coverage are applied and verified through the two CMMB projects which I host and participate in. The network simulation calculation of Nanchang single frequency network is used to determine whether the plan is feasible or not. According to the simulation results, it is found that the effective coverage range is reduced, the same frequency interference, the time is out of sync, the frequency is not synchronized and so on. According to theoretical knowledge and practical experience, respectively, solutions to these problems are put forward. The indoor distribution system of the west terminal of Hongqiao Hub in Shanghai contains the coverage of many kinds of communication signals such as CMMB and GSM,CDMA,WLAN,WCDMA. From this design example, we can conclude the design ideas and methods of the road combination between CMMB and other systems. It provides a reference for CMMB to build indoor distribution system together with other signalling roads in the future. Finally, the structure and research object of the thesis are summarized, and the directions and ideas for further research in CMMB wireless coverage are put forward.
【學(xué)位授予單位】：東華大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2014
【分類號】：TN943

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 殷新;劉蕾;劉鵬;;CMMB中國移動多媒體廣播[J];中國傳媒科技;2008年01期

2 潘長勇;馮景鋒;王勁濤;;地面數(shù)字電視廣播單頻網(wǎng)應(yīng)用實踐[J];電視技術(shù);2010年08期

3 張若文;;室內(nèi)分布系統(tǒng)的設(shè)計[J];電信技術(shù);2007年12期

4 宋衛(wèi)星;潘和;過寶寶;胡仲羽;;移動無線信道中Hata模型的仿真分析[J];大眾科技;2011年01期

5 何劍輝;李熠星;馮景鋒;;地面數(shù)字電視廣播覆蓋網(wǎng)絡(luò)規(guī)劃方法研究[J];廣播與電視技術(shù);2007年01期

6 馮景鋒;劉駿;李國松;;國家地面數(shù)字電視標(biāo)準(zhǔn)單頻網(wǎng)技術(shù)研究[J];廣播與電視技術(shù);2008年06期

7 房雪蓮;蒲云東;;同頻直放站原理及其帶外抑制能力測試[J];江西通信科技;2009年02期

8 黃東巍;;價格不菲 標(biāo)準(zhǔn)龐雜 手機(jī)電視面臨多重考驗[J];通信世界;2009年16期

9 張安峰;;虹橋樞紐綜合交通規(guī)劃[J];上海建設(shè)科技;2007年02期

10 胡珍仁;劉峗;肖幼軍;;吉安市城區(qū)CMMB覆蓋網(wǎng)絡(luò)的建設(shè)[J];聲屏世界;2009年01期

，

本文編號：2314857