地面数字电视传输系统中信道调制的设计与实现

【作者】 张拥军；

【导师】 朱维乐；

【作者基本信息】 电子科技大学 ， 信号与信息处理， 2005， 硕士

【摘要】 本文主要论述地面数字电视传输系统中信道调制的实现,内容涉及到两个系统的信道调制部分,第一个系统是符合欧洲DVB-T 标准的信道编码调制器,文中论述了OFDM 调制的设计与实现;第二个系统是以我国在2004 年9 月份暂定的地面数字电视融合传输方案(以下简称融合方案)为基础的信道编码调制器,文中论述了信号成形的设计与实现。以上模块基于Altera 公司的Stratix 系列器件实现,具体的设计流程包括了算法仿真、VerilogHDL 描述、FPGA 仿真和实际系统测试。在DVB-T 系统OFDM 调制的FPGA 实现中,使用了基于存储器的FFT 结构,只消耗很少的逻辑资源,而且使用了块浮点处理来提高运算精度。经仿真和实际系统测试表明,能够满足实际需求。对FFT 中复数乘法器的实现,作者比较了几种方法,也设计出了相关的FPGA 程序。文中还提出了一种既能实现2k 点又能实现8k 点FFT 运算的电路结构。在融合方案的信号成形的FPGA 实现中,讨论了内插滤波器的FPGA 设计和优化方法。更多还原

【Abstract】 This paper focuses on the implementation of channel coding & modulating of terrestrialdigital television transmission system, and involves channel coder & modulator of two systems.The first section is channel coder & modulator according with Europe’s DVB-T standard. Thedesign and realization of OFDM modulator are discussed in this article. The second system, inwhich design and realization of signal shaping are discussed, is based on mixed transmissionscheme of terrestrial digital television temporarily proposed by China in Sep, 2004(briefly calledmixed scheme below). All the modules are implemented on Altera’s Stratix series FPGA(EP1S25F780) chips. The design flows such as algorithm simulation, Verilog HDL description,FPGA simulation and debug on real system are included in the projects.A FFT architecture based on memory, which consumes less resources comparative to usualFFT architecture, is adopted in OFDM modulator of DVB-T system. Furthermore, block floatingpoint processing is used to increase computing precision. It has been proved that the design canmeet the requirements. Various methods to implement complex multiplication are discussed andan architecture including 2k points FFT processing and 8k points FFT processing in the samecircuits is proposed.In the last section, the FPGA implementation of the interpolating filter for signal shaping ofmixed scheme are discussed.更多还原