碼分多址通信系統(tǒng)、擴頻通信外文翻譯-其他專業(yè)-文庫吧資料
2025-01-27 03:02本頁面
【正文】 y play an important role. 譯文正文 擴頻通信，即擴展頻譜通信（ Spread spectrum munication)，它與光纖通信、衛(wèi)星通信，一同譽為進入信息時代的三大高技術(shù)通信傳輸方式，擴頻通信是將待傳送的信息數(shù)據(jù)被偽隨機碼調(diào)制，實現(xiàn)頻譜擴展后再傳輸；接收端則采用相同的編碼進行解調(diào)及相關(guān)處理，恢復(fù)原始信息數(shù)據(jù)。 chirp frequency system is a linear extension of the process of change. Combination of a number of ways of hybrid systems are often applied. The most important measure pf spreadspectrum system is an indicator of spreading gain, also known as processing gain. It is precisely because of the spread spectrum system itself with its performance characteristics with a series of advantages. Code division multiple access Code division multiple access (CDMA) is a channel access method used by various radio munication technologies. It should not be confused with the mobile phone standards called cdmaOne, CDMA2021(the 3G evolution of cdmaOne) and WCDMA (the 3Gstandard used by GSM carrier), which are often referred to as simply CDMA, and use CDMA as an underlying channel access method. One of the concepts in data munication is the idea of allowing several transmitters to send information simultaneously over a signal munication channel. This allows several users to share a band of frequencies (see bandwidth). This concept is called multiple access. CDMA employs spreadspectrum technology and a special coding scheme( where each transmitter is assigned a code) to allow multiple user to be multiplexed over the same physical channel. By contrast, time division multiple access (FDMA) divides it by frequency. CDMA is a form of spreadspectrum signaling, since the modulated coded signal has a much higher data bandwidth than the data being municated. Spreadspectrum characteristic of CDMA Most modulation schemes try to minimize the bandwidth of this signal since bandwidth is a limited resource. However, spread spectrum use a transmission bandwidth that is several orders of magnitude greater than the minimum required signal bandwidth. One of the initial reasons for doing this was military applications including guidance and munication systems. These system were designed using spread spectrum because if its security and resistance to jamming. Async hronous CDMA has some level of privacy built in because the signal is spread using a pseudorandom code。 Frequencyhopping system using pseudorandom code to control the carrier frequency in a wider band of the change。 中文 2800 字 畢業(yè)設(shè)計英文翻譯 專 業(yè) 電子信息工程 班 級 2021級 學(xué)生姓名 學(xué) 號 課 題 碼分多址通信系統(tǒng)的建模、仿真和設(shè)計 —— 初始化模塊、基站接收模塊 指導(dǎo)教師 2021 年 06 月 10 日 譯文原文 The basic concept of spreadspectrum munication Spread spectrum municati
范文總結(jié)相關(guān)推薦
鄂ICP備17016276號-1