QAM的FPGA實現(xiàn)

電子通信論文編號:TX206 附外文翻譯,原理圖及PCB,論文字?jǐn)?shù):20278,頁數(shù):40

以下為一級目錄,詳細目錄及內(nèi)容請與本站聯(lián)系

目錄

引言………………………………………………………………………………………………1
1  Quartus軟件介紹……………………………………………………………………2
2  數(shù)字調(diào)制技術(shù)…………………………………………………………………………5
3  QAM原理…………………………………………………………………………………10
4  DDS介紹…………………………………………………………………………………25
5 16QAM調(diào)制的FPGA實現(xiàn)……………………………………………………………32 
6  結(jié)論………………………………………………………………………………………36
謝辭……………………………………………………………………………………………37
參考文獻……………………………………………………………………………………38
附錄……………………………………………………………………………………………39

摘  要
 
    正交幅度調(diào)制解調(diào)QAM(quadrature amplitude modulation and emodulation)頻譜利用率，功率利用率高以增強抗干擾性能，是一種高效的數(shù)字調(diào)制解調(diào)方式。他在中、大容量數(shù)字微波通信系統(tǒng)、有線電視網(wǎng)絡(luò)高數(shù)據(jù)傳輸、衛(wèi)星通信等領(lǐng)域被廣泛應(yīng)用。DDS技術(shù)的實現(xiàn)依賴于高速、高性能的數(shù)字器件。，根據(jù)需要方便地實現(xiàn)各種比較復(fù)雜的調(diào)頻、調(diào)相和調(diào)幅功能。DDS 是從相位的概念出發(fā)進行頻率合成的一項新型技術(shù)。本文簡要介紹了DDS 的工作原理，提出了一種選用Altera 公司新發(fā)布嶄新體系的大容量Cyclone系列FPGA來實現(xiàn)DDS 系統(tǒng)的核心部分的設(shè)計方案。并用QUARTUSⅡ6.0 波形仿真。實驗結(jié)果表明，通過各種優(yōu)化措施，設(shè)計開發(fā)的DDS 系統(tǒng)，達到了預(yù)期的目的，具有較高的性價化。AD9761是完成雙通道，高速，10bit CMOS DAC。AD9761主要應(yīng)用于超帶寬通信，I和Q路信息在傳輸時處理。該論文是基于FPGA的QAM實現(xiàn)，用VHDL語言對QAM調(diào)制過程進行編程，主要是QAM星座圖映射和DDS信號源模塊。對輸入信息先經(jīng)過星座圖映射來控制DDS來產(chǎn)生相應(yīng)幅度，相位的數(shù)字已調(diào)信號。該過程要使用Quartus II這軟件，和下載芯片Cyclone。由芯片輸出的信號通過D/A轉(zhuǎn)換，該電路使用AD9761芯片。然后通過低通輸出就是我們想得到的已調(diào)的QAM信號。

關(guān)鍵詞：QAM；VHDL；DDS；QAM星座圖；Quartus II；AD9761；數(shù)字調(diào)制解調(diào)；Cyclone；D/A轉(zhuǎn)換

Abstract

The quadrature amplitude modulation and demodulation QAM(quadrature amplitude modulation and demodulation) frequency  utilization ratio and the power utilization ratio is a high efficiency digitized modulation and demodulation  solution to strengthen the anti- interference function. In the medium  and big capacity digital microwave correspondence system,the high  cable TV networks  data transmission  and  the satellite correspondence etc was extensively applied. DDS  technical realization depend on digitized spare part of the high speed,high performance. According to the need to carry out various more complicated frequency complicated phase complicated range function expediently. The DDS(Direct Digital Synthesis) is a new digital frequency synthesis technique based on theconcept of phase. This paper presents the work principle of DDS. And by using the big capacity FPGA (Cyclone)which is the latest product declared by the Altera company, here brings up a design project to realize thecore of the DDS system. And we also use the QUARTUSⅡ6.0’simulation to wave form. By making use of some optimizing measure, the performance of the DDSsystem designed comes to our anticipant purpose, finally, the experiment result demonstrate that the proposed method has relatively high cost performance ratio. The AD9761 is a complete dual channel, high speed, 10-bit CMOS DAC. The AD9761 has been developed specifically for use in wide bandwidth communication applications where digital I and Q information is being processed during transmit operations. This paper is depended on  FPGA for QAM realization, Use the VHDL language to make process of the QAM modulation，Mainly is the reflection of QAM constellation and  the DDS signal source module. Through the reflection of QAM constellation of the input  information to control DDS to produce to correspond range, phase already modulated digital signal. That process need the Quartus II software and  the download chip Cyclone.  the chip export   pass the D/A conversion, which  use AD9761 chip electric circuit . Then pass a low pass filter are the already modulated of QAM signal we want to get.

Key words: QAM；VHDL；DDS；QAM constellation；Quartus II；AD9761；
digitized modulation and demodulation；Cyclone；D/A conversion