【正文】 Tokyo Denki UniversityThis article describes the latest trends in wireless munication technology, as well as the position of the four parts of the wireless munication technology. The first and most important development is the growth of the global Internet traffic. Summary of important trends in the global Internet traffic growth in the global geographic regions and their Internet penetration. The second part of the supporting hardware necessary to realize the wireless munication backbone network technology development. The third part is the central issue of wireless munications, in particular, local individuals, and the fourth and final part of the concluding remarks.The development of many technologies is clearly through the realization of wireless munications in order to meet the environmental requirements of the social background of this technology development. For example, Internet traffic per year doubled, and this rapid growth in Internet traffic and WWW (WWW) as the backbone network to configure the wireless does not necessarily require huge bandwidth of the vital, but for local wireless munications. Backbone network depends mainly on the technical development of fiberoptic cable and related ancillary technical support to support the run. This and other supporting technologies including information processing and WDM (Wavelength Division Multiplexing) and achieved efficient wireless munications bee possible. Wireless munication, wireless Internet, in particular, wireless Internet focus, even moving a short distance within the scope of local individual users is very important. The IEEE wireless LAN for and cooperation with media access control protocol of the general principles can be extended to other types of wireless networks, such as wireless personal area network (WPAN). The scope of the service area to bee smaller, to allow local individuals to take full advantage of wireless munication media.For wireless Internet traffic. Wireless munication is the most convenient wireless Internet transmission medium, the effective use of the wireless transmission medium is critical. Reliable access to dozens of MHz geographic area across fairly large in which the wireless Internet will require ten times more cells in the voice system, the small size of each of monocles will measure dozens of square meters is about percent the size of the conventional cell. Than traditional batteries, it can acmodate more for a given data rate of the active device. In order to make this possible, the radio spectrum spatial reuse is necessary, in order to allow individual users access closer to the lowpower transmission point.The overall munication system for the rapid growth of Internet traffic can be supported by three key areas of technology development, 1) hardware technology needs of individual users wireless transmission of highdensity implementation, 2) supporting hardware technology of fiberoptic cable, 3 ) the overall munication system operation and maintenance of software technology, we reviewed the first two parts of the hardware aspects.The highest Internet penetration rate highest in 24 countries. The highest penetration rate (% of the population) is % ( million Internet users in Sweden), Han Hong Kong, the second % ( million), the third Danish % (370 million), followed by Norway % ( million) and percent ($ 2,010,000). The world39。衷心的感謝評審老師在百忙中抽出寶貴時間仔細(xì)審閱我的論文。本人在此對諸位領(lǐng)導(dǎo)、老師和工作人員表示衷心的感謝。同時感謝所有執(zhí)教我們的老師，你們淵博的知識、嚴(yán)謹(jǐn)?shù)闹螌W(xué)、高尚的道德、濃厚的學(xué)習(xí)氛圍給我們留下了難忘的印象。此次課題研究與論文的完成傾注著他的巨大心血。另外，本文也存在一定不足之處：① 程序設(shè)計過程中，針對信號解調(diào)過程中濾波器階數(shù)選擇存在一定問題，依照計算出的理論值來設(shè)定的話，存在一定誤差；② 該仿真平臺未對數(shù)字通信系統(tǒng)中的多進(jìn)制調(diào)制信號進(jìn)行仿真，以后進(jìn)一步完善。在模擬通信系統(tǒng)中完成了針對AM、DSB、SSB、FM、PM五種信號的仿真實(shí)現(xiàn)，仿真過程中可以自由的改變各信號的仿真參數(shù)，可以觀看各部分仿真波形；在數(shù)字通信系統(tǒng)中完成了針對2ASK，2FSK，2PSK，2DPSK四種信號的仿真實(shí)現(xiàn)，仿真過程中也可以自由的改變各信號的仿真參數(shù)，可以觀看各部分仿真波形。結(jié) 論 通信原理課程較為抽象，存在難理解、難消化、不直觀的特性，為此本設(shè)計對通信原理課程通用性仿真平臺進(jìn)行詳細(xì)設(shè)計，旨在開發(fā)一種適用于通信原理課程的教學(xué)仿真軟件。 2DPSK解調(diào)后的信息碼時域與頻域波形 仿真結(jié)果及分析通過對四種數(shù)字信號2ASK，2FSK，2PSK，2DPSK的仿真可知，在無噪聲干擾的情況下，解調(diào)出的信號與基帶信號完全一致；在加入高斯白噪聲的情況下，存在一定誤碼，這與課程理論相吻合，進(jìn)而說明了程序設(shè)計的正確性。、。其頻譜由連續(xù)譜和離散譜組成，在頻率為100處的地方出現(xiàn)波峰，與2DPSK信號的調(diào)制原理一致。經(jīng)傅里葉變換。在零點(diǎn)處出現(xiàn)波峰。 解調(diào)后信號的時域波形與頻譜 二進(jìn)制差分相移鍵控(2DPSK)信號仿真⑴ 相對碼時域波形與頻譜圖未經(jīng)調(diào)制的基帶信號為隨機(jī)產(chǎn)生的信息碼，轉(zhuǎn)換成相對碼。、。其頻譜由連續(xù)譜和離散譜組成，在頻率為100處的地方出現(xiàn)波峰，與2PSK信號的調(diào)制原理一致。經(jīng)傅里葉變換，[39][40]。在零點(diǎn)處出現(xiàn)波峰。 解調(diào)后的信號時域波形與頻譜 二進(jìn)制相移鍵控(2PSK)信號仿真⑴ 信息碼時域波形與頻譜圖未經(jīng)調(diào)制的基帶信號為隨機(jī)產(chǎn)生的信息碼，為雙極性不歸零波形。、。近似表示成中心頻率為150Hz和100Hz的兩個2ASK頻譜組合。 載波的時域波形與頻譜⑶ 2FSK信號的時域波形與頻譜圖。 隨機(jī)碼元的時域波形與頻譜⑵ 載波時域波形與頻譜圖采用正弦波作為調(diào)制基帶信號的載波。經(jīng)傅里葉變換后得到頻譜圖。 加噪后2ASK信號的時域波形與頻譜⑸ 相干解調(diào)后得到的信息碼時域波形與頻譜圖經(jīng)過相干解調(diào)器后，在信噪比為10的情況下，原輸入信息碼一致。 2ASK信號時域波形與頻譜⑷ 加噪后2ASK信號的時域波形與頻譜圖信號經(jīng)過信道傳輸時總會受到噪聲的干擾，這樣形成了正弦波與高斯噪聲的混合波形。 載波時域波形與頻譜⑶ 2ASK信號的時域波形與頻譜圖。 信息碼時域波形與頻譜⑵ 載波時域波形與頻譜圖采用正弦波作為調(diào)制基帶信號的載波。隨機(jī)脈沖序列沒有確定頻譜函數(shù)，經(jīng)傅里葉變換后得到頻譜圖。生成的界面如下： GUI界面的設(shè)計 總體設(shè)計參數(shù) 總體設(shè)計參數(shù)參數(shù)碼元速率載波頻率采樣頻率信噪比碼元長度碼元個數(shù)總時間時間間隔參考位2ASK5100100010520011/10002FSK5100/150100010520011/10002PSK5100100010520011/10002DPSK5100100010520011/10000 仿真實(shí)現(xiàn) 信號調(diào)制解調(diào)程序流程圖。界面中設(shè)置2個Push Button（畫圖與清空），11個radio button（四種調(diào)制方式，五種信號表現(xiàn)形式以及時域與頻域）。因此，在GUI界面中設(shè)置系統(tǒng)的這4個參數(shù)。 總體設(shè)計方案下面以二進(jìn)制幅度鍵控鍵控(2ASK)為例，說明基于MATLAB的數(shù)字通信仿真系統(tǒng)的設(shè)汁。使人們對不同數(shù)字通信系統(tǒng)的性能差別有更進(jìn)一步的認(rèn)識。利用GUI圖形用戶界面，輸人參數(shù)，設(shè)置按鈕，并通過用戶界面看到仿真結(jié)果。5 數(shù)字通信系統(tǒng)仿真實(shí)現(xiàn) 仿真平臺功能在數(shù)字通信的教學(xué)和設(shè)計中，傳統(tǒng)的方法主要是手工分析與電路板試驗(yàn)，通信系統(tǒng)中所有變量相互之間是非線性的關(guān)系，大部分是較為繁瑣的數(shù)字理論和推導(dǎo)，容易使學(xué)生感到乏味和難以接受。利用自動增益控制和帶通限幅還可以消除快衰落造成的幅度變化效應(yīng)。SSB調(diào)制的優(yōu)點(diǎn)是功率利用率和頻帶利用率都較高，抗干擾能力和抗選擇性衰落能力均優(yōu)于AM，而帶寬只是AM的一半；缺點(diǎn)是發(fā)送和接收設(shè)備都較復(fù)雜。 總體設(shè)計參數(shù)（AM）參數(shù)設(shè)計要求 AM參數(shù)設(shè)計采樣頻率（）基帶頻率（）載波頻率（）信噪比（）任意值任意值雙邊帶調(diào)制（DSB）參數(shù)設(shè)計要求 DSB參數(shù)設(shè)計采樣頻率（）基帶頻率（）載波頻率（）信噪比（）任意值任意值單邊帶調(diào)制（SSB）參數(shù)設(shè)計要求 SSB參數(shù)設(shè)計采樣頻率（）基帶頻率（）載波頻率（）信噪比（）任意值任意值頻率調(diào)制（FM）參數(shù)設(shè)計要求 FM參數(shù)設(shè)計采樣頻率（）基帶頻率（）載波頻率（）信噪比（）調(diào)制指數(shù)（K）任意值任意值任意值相位調(diào)制（PM）參數(shù)設(shè)計要求 PM參數(shù)設(shè)計采樣頻率（）基帶頻率（）載波頻率（）信噪比（）調(diào)制指數(shù)（K）任意值任意值 模擬通信系統(tǒng)仿真實(shí)現(xiàn) 信號調(diào)