文档介绍：南京航空航天大学
硕士学位论文
软件无线电系统数字中频接收模块的设计与实现
姓名:周丽君
申请学位级别:硕士
专业:通信与信息系统
指导教师:朱钢
20070101
南京航空航天大学硕士学位论文
摘要
传统无线电收发系统硬件依赖性强、信号适应能力差,软件无线电技术的出
现导致了收发机的革新。其基本思想是对射频进行采样,在高速 DSP 处理平台
上加载不同的软件实现不同的功能。鉴于目前器件水平的限制,现阶段尚无法对
射频直接采样,只能在中频进行采样并使用专用芯片来完成中频模块的设计。
本文讨论了软件无线电中频接收模块的实现方法。首先从阐述软件无线电的
理论基础入手,对多速率采样技术、数字下变频以及数字信号的调制/解调技术
等问题进行了分析与探讨。然后建立系统的实现方案,选择合适的芯片设计系统
的硬件电路,接着叙述了数字下变频、系统的 DSP 以及信号解调算法的程序流
程设计步骤。最后,基于 MATLAB 仿真环境建立 Simulink 仿真框图。对 DSB
信号和 QPSK 信号进行相干解调中频接收仿真和分析。
关键词:软件无线电,中频,多速率采样,数字下变频,相干解调
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软件无线电系统数字中频接收模块的设计与实现
Abstract
Conventional transceiver depends on hardware much more. The emergence of
software radio results in transceiver’s renovation. The basic idea is to sample RF
signal, process the digital signal by installing different software to implement different
functions on a high-speed DSP platform. Due to the limitation of device level, it is
impossible to sample RF signal in direct now and have to choose the middle
project---sampling IF signal, using special chips to build the intermediate frequency
module.
This paper discusses the realization of the digital intermediate frequency receiver
module in software radio system. Firstly it expatiates on the theory of software radio,
discussing the Multi-rate Sampling, Digital Down Converting(DDC) and the Digital
Signal Modulation/Demodulation and so on. Then on the basis of those, a scheme of
the system is given, and the hardware circuits are built with appropriate chips. In
ession, it discusses the software programme development flow. Finally, its
establishment simulation diagram of Simulink under the MATLAB environment.
Carrying on the coherent demodulation intermediate frequency receive simulation and
the analysis to the AM signal and the QPSK signal are on the system of Simulink.
Keywords: software radio, intermediate frequency, Multi-rate sample, Digital Down
Converting(DDC), coherent demodulation
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南京航空航天大学硕士学位论文
图表清单
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