【正文】 At present, a number of mobile streaming media service has been able to achieve the networks, 3G networks will provide mobile service development to provide more effective support. 由于3G網(wǎng)絡(luò)擁有更高的數(shù)據(jù)傳輸速率和數(shù)據(jù)業(yè)務(wù)支撐能力，3G運(yùn)營(yíng)商不僅可以向用戶提供高質(zhì)量的語(yǔ)音業(yè)務(wù)，而且還能。s leading international financial in which, in the spectrum efficiency, flexibility of business support, frequency, flexibility and cost etc. unique advantage. 另外，由于中國(guó)內(nèi)的龐大的市場(chǎng)，該標(biāo)準(zhǔn)受到各大主要電信設(shè)備廠商的重視，全球一半以上的設(shè)備廠商都宣布可以支持TDSCDMA標(biāo)準(zhǔn)。 As the procurement of the equipment prior to support CDMA2000 standard, China Tele does not require rebuilding of networks, 3G license issuance, the need to do a software upgrade, China Tele will be the first time since the building of a national 3G network coverage. TDSCDMA是由中國(guó)大陸?yīng)氉灾贫ǖ?G標(biāo)準(zhǔn)，該標(biāo)準(zhǔn)將智能無(wú)線、同步CDMA和軟件無(wú)線電等當(dāng)今國(guó)際領(lǐng)先技術(shù)融于其中，在頻譜利用率、對(duì)業(yè)務(wù)支持具有靈活性、頻率靈活性及成本等方面的獨(dú)特優(yōu)勢(shì)。s wireless Internet access. 中國(guó)電信還發(fā)布了“天翼”品牌并啟動(dòng)了189號(hào)段放號(hào)。One結(jié)構(gòu)直接升級(jí)到3G，日前， 中國(guó)電信集團(tuán)公司獲得增加基于CDMA2000技術(shù)制式的3G業(yè)務(wù)經(jīng)營(yíng)許可，中國(guó)電信在收購(gòu)了中國(guó)聯(lián)通CDMA網(wǎng)絡(luò)之后，啟動(dòng)了44個(gè)重點(diǎn)城市的網(wǎng)絡(luò)優(yōu)化工程，并于去年年底前完成了340多個(gè)城市的CDMA網(wǎng)絡(luò)建設(shè)工作，滿足了82個(gè)無(wú)線城市的無(wú)線上網(wǎng)需求。MultiCarrier，由美國(guó)高通北美公司為主導(dǎo)提出，這套系統(tǒng)是從窄頻CDMA WCDMA or WidebandCDMA, also known as CDMA Direct Spread, which means the broadband code division multiple access, its supporters are mainly the European GSM system, the main manufacturer, the system can be set up in the existing GSM network on the , for system providers, the transition can be a lesser exsitu, while the GSM system, quite popular in Asia for the acceptance of this new technology expected to be quite high. 因此WCDMA具有先天的市場(chǎng)優(yōu)勢(shì)。Direct 3G base station with a programmable electronic phase relationship with adaptive antenna arrays, can be written beamforming, adaptive adjustment of power, reducing the system selfinterference and improve receiver sensitivity, increasing the system capacity, another softwaredefined radio technology in the the base station and terminal products application, improving the system flexibility and reduce costs is essential.3, 3G technical standards 國(guó)際電信聯(lián)盟（ITU）在2000年5月確定WCDMA、CDMA2000和TDSCDMA三大主流無(wú)線接口標(biāo)準(zhǔn)，寫(xiě)入3G技術(shù)指導(dǎo)性文件《2000年國(guó)際移動(dòng)通訊計(jì)劃》（簡(jiǎn)稱IMT2000）。 In the broadband channel, can be flexible application of time multiplexing, code multiplexing, individual control of each business, power and quality, by selecting a different spreading factor, will have different QoS requirements of various speeds of broadband service is mapped to channel to realize multiservice, multirate transmission. （四）快速功率控制 (D) Fast power control 3G主流技術(shù)均在下行信道中采用了快速閉環(huán)功率控制技術(shù)，用以改善下行傳輸信道性能，這一方面提高了系統(tǒng)抗多徑衰落能力，但另一方面由于多徑信道影響導(dǎo)致擴(kuò)頻碼分多址用戶間的正交性不理想，增加了系統(tǒng)自干擾的偏差，但總體上快速功率控制的應(yīng)用對(duì)改善系統(tǒng)性能是有好處的。 To achieve the goal of global roaming, according to ITU planning IMT2000 will be uniform application of 2G spectrum, the available bandwidth of up to 230MHz, assigned to the terrestrial network of 170MHz, satellite network 60MHz, which the network capacity for 3G development, and achieve global multiservice environment provides a broad spectrum space, while better meet the broadband business. （二）采用寬帶射頻信道，支持高速率業(yè)務(wù) (B) the adoption of broadband radio channel to support highspeed services 充分考慮承載多媒體業(yè)務(wù)的需要，3G網(wǎng)絡(luò)射頻載波信道根據(jù)業(yè)務(wù)要求，可選用5/10/20M等信道帶寬，同時(shí)進(jìn)一步提高了碼片速率，系統(tǒng)抗多徑衰落能力也大大提高。 Cellular mobile munication system of wireless technology, including cell multiplexing, multiple access / duplex mode, the application frequency, modulation techniques, radiofrequency channel parameters, channel coding and error correction techniques, frame structure, the physical channel structure and reuse patterns and other aspects. 縱觀3G無(wú)線技術(shù)演變，一方面它并非完全拋棄了2G，而是充分借鑒了2G網(wǎng)絡(luò)運(yùn)營(yíng)經(jīng)驗(yàn)，在技術(shù)上兼顧了2G的成熟應(yīng)用技術(shù)，另一方面，根據(jù)IMT2000確立的目標(biāo)，未來(lái)3G系統(tǒng)所采用無(wú)線技術(shù)應(yīng)具有高頻譜利用率、高業(yè)務(wù)質(zhì)量、適應(yīng)多業(yè)務(wù)環(huán)境，并具有較好的網(wǎng)絡(luò)靈活性和全覆蓋能力。 In order to provide this service, wireless network must be able to support different data transfer rate, ie indoor, outdoor, and driving environment can support at least the respective 2MBps (MB / sec), 384KBps (1000 bytes / sec) as well as the transmission speed of 144KBps. 二、3G技術(shù)基本特點(diǎn) 2, 3G technology, the basic characteristics of 從目前已確立的3G標(biāo)準(zhǔn)分析，其網(wǎng)絡(luò)特征主要體現(xiàn)在無(wú)線接口技術(shù)上。 Relative firstgeneration analogue phones (1G) and secondgeneration GSM, TDMA and other digital mobile phones (2G), thirdgeneration mobile phones generally speaking, refers to wireless munications and the Internet and other multimedia munications with a new generation of mobile munications systems. 它能夠處理圖像、 音樂(lè) 、視頻流等多種媒體形式，提供包括網(wǎng)頁(yè)瀏覽、電話會(huì)議、 電子商務(wù)等多種信息服務(wù)。Generation的縮寫(xiě)，指第三代移動(dòng)通信技術(shù)。 3G is currently still in its infancy, but its prospects are extremely good. 隨著通信網(wǎng)絡(luò)和技術(shù)的不斷發(fā)展，3G技術(shù)環(huán)境下電信增值業(yè)務(wù)進(jìn)入了高速發(fā)展，業(yè)務(wù)范圍持續(xù)擴(kuò)大，經(jīng)營(yíng)主體趨向多元，經(jīng)營(yíng)模式日益創(chuàng)新的新階段。 This paper introduces the 3G (third generation mobile munication systems), and the meaning of the basic characteristics of 3G technology, analysis of the 3G technology in munications applications. 面向未來(lái)，人們對(duì)3G技術(shù)充滿了美好的期待。 Abstract: Currently, 3G is still in its infancy, but its development prospects are extremely good. 隨著通信網(wǎng)絡(luò)和技術(shù)的不斷發(fā)展，3G技術(shù)環(huán)境下電信增值業(yè)務(wù)進(jìn)入了高速發(fā)展，業(yè)務(wù)范圍持續(xù)擴(kuò)大，經(jīng)營(yíng)主體趨向多元，經(jīng)營(yíng)模式日益創(chuàng)新的新階段。 power。 munications。感謝我的父母，感謝他們對(duì)我的養(yǎng)育之恩，感謝他們給予我的學(xué)業(yè)以最大的支持。感謝朱彬，李軼婷，田玉剛以及所有通信062班的全體同學(xué)在學(xué)習(xí)和工作中所給予的幫助，與你們的朝夕相處和對(duì)學(xué)術(shù)問(wèn)題的討論使我受益匪淺，和你們?cè)谝黄鹫娴暮瞄_(kāi)心，真心的感謝你們，預(yù)祝你們學(xué)業(yè)有成，早日實(shí)現(xiàn)自己的抱負(fù)。無(wú)論在學(xué)業(yè)上還是在生活上，導(dǎo)員們都給了我很多幫助，也教會(huì)我很多知識(shí)，在此表示衷心的謝意。在這里作者對(duì)吳麗華老師三年來(lái)的關(guān)心和教誨表示衷心的感謝。吳麗華老師以其豐富的知識(shí)和嚴(yán)謹(jǐn)?shù)闹螌W(xué)態(tài)度關(guān)心指導(dǎo)了作者的每一步工作，使我受益匪淺。致謝值此論文完成之際，我首先要感謝我的導(dǎo)師吳麗華老師?？傊?，本系統(tǒng)的設(shè)計(jì)打破了傳統(tǒng)的設(shè)計(jì)方式，性能價(jià)格比高。通過(guò)管理軟件，上位機(jī)可以獲取各糧倉(cāng)的當(dāng)前溫濕度數(shù)據(jù)，并將數(shù)據(jù)存入數(shù)據(jù)庫(kù)中；同時(shí)，上位機(jī)軟件還有強(qiáng)大的數(shù)據(jù)顯示功能，通過(guò)訪問(wèn)數(shù)據(jù)庫(kù)，軟件為用戶提供溫度數(shù)據(jù)的表格顯示，各層溫度的曲線變化圖和總體溫度變化趨勢(shì)圖，以便進(jìn)行糧情分析。通訊控制站與各個(gè)分機(jī)之間采用了RS485協(xié)議，形成一點(diǎn)對(duì)多點(diǎn)的主從式多機(jī)串行通訊。通訊控制站實(shí)現(xiàn)與上位機(jī)的串行數(shù)據(jù)傳輸和對(duì)分機(jī)的溫濕度數(shù)據(jù)采集和存儲(chǔ)。整個(gè)系統(tǒng)具備抗干擾能力強(qiáng)，數(shù)據(jù)通訊速度快，通訊誤碼率低，容量大的特點(diǎn)?！敖Y(jié)論”以前的所有正文內(nèi)容都要編寫(xiě)在此行之前。糧庫(kù)的儲(chǔ)糧信息不是一成不變的，季節(jié)的變換和糧食的不斷流入流出，糧食品種、來(lái)源會(huì)發(fā)生改變，同時(shí)由于規(guī)模上會(huì)存在擴(kuò)建等情況，參數(shù)信息需要進(jìn)行變更；參數(shù)的變化會(huì)導(dǎo)致整個(gè)系統(tǒng)在測(cè)溫系統(tǒng)配置等多方面的不同，在軟件已經(jīng)運(yùn)行的情況下，如參數(shù)信息發(fā)生改變就要重新更改軟件的源程序并進(jìn)行重新安裝顯然是不可取的，另外，也是為了適應(yīng)不同的糧庫(kù)，達(dá)到可移植的目的，因此更改后的信息會(huì)自動(dòng)存入數(shù)據(jù)庫(kù)，刷新數(shù)據(jù)庫(kù)的存儲(chǔ)信息，而軟件的整個(gè)運(yùn)行過(guò)程對(duì)于糧倉(cāng)各參數(shù)信息的獲取都是和數(shù)據(jù)庫(kù)是緊密相連的，很多檢測(cè)、管理的相關(guān)參數(shù)都是與數(shù)據(jù)庫(kù)鏈接，運(yùn)行時(shí)通過(guò)查詢數(shù)據(jù)庫(kù)得到的，因此數(shù)據(jù)庫(kù)信息的變更直接帶動(dòng)整個(gè)軟件管理系統(tǒng)參數(shù)的自行變動(dòng)。例如檢測(cè)信息表中1號(hào)倉(cāng)測(cè)溫點(diǎn)數(shù)為64，則當(dāng)測(cè)溫點(diǎn)數(shù)變動(dòng)為60時(shí)，上位機(jī)相應(yīng)收到的數(shù)據(jù)點(diǎn)數(shù)信息會(huì)有所不同，通過(guò)輸入新的參數(shù)信息，則軟件即應(yīng)用于新的糧庫(kù)中而不是大量更改源程序，這樣一來(lái)就大大節(jié)省了軟件開(kāi)發(fā)的周期和成本降低了整個(gè)系統(tǒng)的開(kāi)發(fā)成本。比如，要改變糧庫(kù)布局示意圖，只需修改“系統(tǒng)維護(hù)”中的有關(guān)糧庫(kù)的一些參數(shù)信息，像儲(chǔ)備倉(cāng)數(shù)目，安裝分機(jī)數(shù)目，各倉(cāng)內(nèi)電纜總數(shù)、測(cè)溫點(diǎn)數(shù)等，就可以進(jìn)行對(duì)不同糧庫(kù)的檢測(cè)監(jiān)控。實(shí)踐已經(jīng)證明，軟件復(fù)用技術(shù)不僅可以