基于C語言實(shí)現(xiàn)的QPSK通信系統(tǒng)

通信工程論文編號:TX334  論文字?jǐn)?shù):10005,頁數(shù):36

目錄

摘要 I
ABSTRACT II
第1章 引言 1
 1.1 背景 1
 1.2 研究內(nèi)容 3
第2章 QPSK系統(tǒng)的基本原理 4
 2.1 QPSK基本原理 4
 2.2數(shù)字頻帶傳輸系統(tǒng) 5
第3章 QPSK系統(tǒng)的主要技術(shù) 7
 3.1信道編碼 7
 3.1.1卷積碼 7
 3.2 信道解碼 9
 3.2.1 Viterbi譯碼 9
 3.3 數(shù)字調(diào)制 10
 3.3.1 QPSK 10
第4章 基于卷積碼的QPSK系統(tǒng)設(shè)計(jì) 13
 4.1 系統(tǒng)模型及仿真流程 13
 4.2信道 14
 4.2.1 瑞利衰落信道 14
 4.2.2 AWGN信道 15
 4.2.3 萊斯信道 15
第5章 仿真及結(jié)果分析 16
 5.1 仿真平臺 16
 5.2 仿真結(jié)果分析 16
 5.2.1 在瑞利衰落信道下的QPSK系統(tǒng)的仿真 16
 5.2.2 在AWGN信道下的QPSK系統(tǒng)的仿真 17
第6章 結(jié)束語 19
致謝 20
參考文獻(xiàn) 21
附錄（程序） 22

摘要

 QPSK是一種頻譜利用率高、抗干擾性強(qiáng)的數(shù)調(diào)制方式，它被廣泛應(yīng)用于各種通信系統(tǒng)中，如現(xiàn)在3G通信系統(tǒng)中的WCDMA系統(tǒng)，其下行鏈路調(diào)制采取了QPSK調(diào)制。采用QPSK 調(diào)制方式，同時保證了信號傳輸?shù)男�率和誤碼性能。加入了卷積碼編碼能有效降低QPSK通信系統(tǒng)的誤碼率，更能確保信號傳輸?shù)臏?zhǔn)確性和可靠性。
 本文設(shè)計(jì)了一個基于卷積碼的QPSK通信系統(tǒng)，并在計(jì)算機(jī)上進(jìn)行了仿真和結(jié)果分析。全文主要由四部分構(gòu)成：QPSK系統(tǒng)基本原理、基于卷積碼編碼的QPSK系統(tǒng)設(shè)計(jì)、基于Viterbi譯碼的QPSK系統(tǒng)設(shè)計(jì)、仿真及結(jié)果分析。
 本文完成了對一個完整的QPSK系統(tǒng)的設(shè)計(jì)與仿真，用C語言實(shí)現(xiàn)了整個系統(tǒng)的計(jì)算機(jī)仿真并給出參考設(shè)計(jì)程序。先進(jìn)行QPSK調(diào)制，對比特?cái)?shù)據(jù)用卷積碼編碼，再通過信道，然后進(jìn)行解調(diào)，最后對其進(jìn)行Viterbi譯碼，計(jì)算出誤碼率和描繪仿真圖。
 
關(guān)鍵詞：QPSK，卷積碼編碼，Rayleigh信道，Awgn信道，Viterbi譯碼，誤碼率

ABSTRACT

 QPSK is a kind of modulation which has high spectrum efficiency and strong anti-jamming, it is widely used in various communication systems. Such as WCDMA system in the 3G communication systems,Its Downlink Modulation take QPSK modulation. Using QPSK modulation, while ensuring that the signal transmission efficiency and BER. Joined the convolutional code encoder can be reduced effectively QPSK communication system bit error rate. can also ensure the signal transmission accuracy and reliability.
 In this paper, based on convolutional code ,a QPSK system is analyzed, designed and simulated on computer. This paper mainly consists of four parts: the basic principles of QPSK system, the design of QPSK system witch based on convolutional coding, the design of QPSK system witch based on Viterbi encoding, the system simulation and the analysis of the results.
 This paper has designed and simulated an intergrated baseband QPSK system, simulated the system with C language and given reference design process, First QPSK modulation，using convolutional codes to encode bits of data,through channel，then Demodulator and Viterbi decoding,calculating its error rate and depicting Simulation diagram.
 
 Keywords：Quadrature Phase Shift Keying，Convolutional Coding，The Rayleigh channel，AWGN channel，Viterbi decoding，Code error rate