【作者】 李延生；

【导师】 余宁梅；

【作者基本信息】 西安理工大学 ， 电路与系统， 2008， 硕士

【摘要】 数字音频广播（Digital Audio Broadcasting-DAB）是继调幅（AM）、调频（FM）之后的第三代广播,其以数字技术为基础,对信号进行音频数字编码、数据压缩、纠错编码和数字调制。目前国内对DAB基带解码芯片的研究多是基于DSP,面对未来DAB未来巨大的消费市场必须要设计基带解码专用集成电路,而且国内对发射基站的建设研究也很少。针对这种情况,本文分析了DAB基带系统结构,并利用MATLAB与SIMULINK相结合的平台搭建了基带系统的模型并进行仿真,模型可以在规范规定的四种模式下正常工作,为基带解码芯片的专用集成电路设计提供了必要测试平台,同时为发射基站的设计提供了重要依据。模型加入多径衰落信道模型和高斯白噪声信道,本文仿真中把AWGN信道分为E_b/N₀=2.5dB,5dB,10dB,20dB四种情况,分别讨论分析了多普勒频移对控制信道和主信道在最低级、最高级音频编码保护等级下的性能影响,其它保护等级的性能位于这两者之间。从而得到不同情况下的信道误码率,最后通过一副768*768的Lena图像与经过信道传输解码恢复后的Lena图像对比,使信道性能更为直观。最后进行了信道解码（解能量扩散、Viterbi译码、解时间交织）的电路设计,完成了RTL代码编写、功能仿真。模型仿真结果表明,本文所搭建的模型完全符合我国广播电影电视总局于2006年5月10日颁布的我国数字音频广播标准——((30MHz～3000MHz地面数字音频广播系统技术规范》,电路设计部分在本文搭建的模型平台上测试证明功能正确。更多还原

【Abstract】 Digital Audio Broadcast is the third era broadcast after the AM、FM traditional broadcast based on digital technology with digital audio coding,data compression,error correcting coding, and digital modulation.Most of domestic researches on DAB base-band decoding are based on DSP at present.We must make an ASIC design of DAB decoder on base-band facing the huge market.Moreover, the research on transmitting station is very rare in our country.System model in this paper is built based on SIMULINK and MATLAB.The model can Operate at four transmission modes. And it provides test platform for ASIC design of DAB base-band decoding and provides important proof for design of transmitting station.Multipath fading channel and AWGN channel are added to the model.AWGN channel is divided into four cases:E_b/N₀=2.5dB,5dB,10dB,20dB and then discuss and analyze properties of FIC and MSC under the highest and the lowest coding protection level respectively affected by Doppler shift.The others are between the highest and the lowest level.We get BERs of the channel under different conditions at last.A Lena gray image is transformed through the system for intuitive experience of properties of channel.At the last of this paper,circuit design of channel decoding including energy de-dispersal, Viterbi decoder and time de-interleaver is gave out.RTL codes and function simulations have been done.Model Simulation results show that the structures are fully consistent with "Specification of 30MHz-3000MHz terrestrial digital audio broadcasting system" which was issued by The State Administration of Radio Film and Television of China on May 10th,2006,and circuit design of channel decoder work well which is tested by the system model.更多还原