【作者】 刘庆丰；

【导师】 陈金鹰；

【作者基本信息】 成都理工大学 ， 通信与信息系统， 2010， 硕士

【摘要】 随着数字时代的到来,信息化程度的不断提高,人们相互之间的信息和数据交换日益增加。正交幅度调制器(QAM Modulator)作为一种高频谱利用率的数字调制方式,在数字电视广播、固定宽带无线接入、卫星通信、数字微波传输等宽带通信领域得到了广泛应用。近年来,集成电路和数字通信技术飞速发展,FPGA作为集成度高、使用方便、代码可移植性等优点的通用逻辑开发芯片,在电子设计行业深受欢迎,市场占用率不断攀升。本文研究基于FPGA与BCM3034实现QAM调制的全过程。FPGA实现信源处理、信道编码输出基带I/Q信号,BCM3034实现对I/Q信号的调制,输出中心频率为36MHz、带宽为8MHz的中频信号,通过上变频器对中频信号进行上变滤波放大,输出中心频率为110MHz～870MHz的可变射频频率,并且步进100KHz可调。输出功率的范围为-7dBm～3dBm,并且步进为1dBm连续可调。本文具体内容总结如下:1.介绍了国内外数字电视发展状况、国际的数字广播电视标准,并详细介绍了数字有线电视广播系统的系统结构及论文选题意义等。2.研究了QAM调制解调的基本原理,然后重点论证QAM调制器的系统方案设计,提出了以FPGA为核心的硬件解决方案并对其进行了主要功能模块的划分,划分成系统接口模块、TS流处理模块、信道编码及调制模块和射频调制模块,并对每个模块逐一加以讨论。3.深入研究了基于FPGA与BCM3034电路设计,其中包括对BCM3034芯片介绍、FPGA型号的选取及详细研究BCM3034部分电路设计,做成成品。4.深入研究了数字电视上变频器电路设计,从数字电视上变频工作原理出发,讲述了对本振源设计、滤波器设计、电平可调衰减电路设计、分段滤波选择电路设计和射频功率衰减器设计五个模块进行了软硬件重点讨论,然后展示电路成品。5.研究测试与实验结果,主要由三方面内容,其中包括DVB-C国家广电总局指标要求及指标的描述、电路测试和指标测试。总体测试结果表明设计成功。所以基于FPGA与BCM3034 DVB-C调制器总体设计完全成功。更多还原

【Abstract】 When stepping into the digital era, the information exchange among people became more and more popular. As a high band-efficiency digital modulation scheme, QAM (Quadrature Amplitude Modulation) Modulator is widely adopted in the wide-band communication era, such as Digital Video broadcasting, Fixed Broadband Wireless Access, Satellite Communication, Digital Microwave Transmission and so on.Paper research mainly embodies in the following aspects: Firstly,by compareing the development of international digital television and the standard of international digital TV broadcasting,analyse the structure of digital TV broadcasting and the basic principle of demodulation QAM modulation, come up with the way of making FPGA to be core,controlling BCM3034 to realize QAM demodulation hardware system resolution.The content include system interface to handle modules, TS stream, channel code modulation, RF module, and for each module has a hardware circuit design. Secondly, by researching digital TV changing fluence,and then accord system structure to do power、RF power design.Thirdly, according the request and description of DVB-C, by using number and spectrum analyser vector analyzer, net analyzer, code stream player to analyse the designed circuit,including DVB-C demodulation tesing,MPEC-2 code stream tesing,modulation error rate testing.In recent years, with the great progress made in the field of IC and digital communication, FPGA become more and more popular in Electronic Industry, as it features high integration, convenience, code portability and so on. This paper studies the implementation of QAM modulation on the FPGA and BCM3034, source process and base band I/Q signal output from channel coding are implemented on FPGA, IF signal output by modulating I/Q signal are implemented on BCM3034. The frequency is 36MHz and the bandwidth is 8MHz. Through used up-converter, the IF signal are up-converted、filtered and amplified. The RF signal are outputted, which’s frequency is 110MHz～870MHz. The RF signal’s frequency is adjustable with 100 KHz step. The output signal power range from -7dBm to 3dBm, which is adjustable with 1dBm step. The main contribution of this paper can be concluded as following:1. Current situation of International and Domestic digital TV development and general situation of International standards of digital TV are introduced. The composition of Community Antenna Television and significance of the paper are described in detail.2. The basic principle of QAM modulation and demodulation are studied, and QAM modulator system design is elaborated. The solution based on FPGA is offered and is divided into four modules which are the system interface module, the TS stream processing module, the channel coding and modulation module, the RF modulator module. Then each module is introduced one by one.3. Circuit Design Based on FPGA and BCM3034 is studied, including the introduction of the BCM3034 chip and FPGA model selection. The BCM3034 circuits are detailed study. The product is demonstrated.4. Digital TV up-converter circuit is studied. Based on digital television up-converter working principle, the paper describes the design of the local oscillator, the design of filter, the design of power adjustable attenuation circuit, the design of the selectable filter circuit and the design of RF power attenuator circuit. The product is demonstrated.5. Testing and experimental results are introduced. Three aspects mainly are elaborated, which are DVB-C standard index’s demand and description, circuit test and index test. Overall test results meet requirements. The test results indicate that DVB-C modulator based on FPGA and BCM3034 has met the national standards.更多还原