【摘要】 扩频通信是一种有着极其优异性能的通信方式,自其诞生之日起就受到了广泛的关注。论文围绕数字化DS-BPSK接收机的解扩模块展开,主要研究了直扩接收机中的数字下变频、伪码快捕与跟踪等内容,设计了针对DS-BPSK信号的解扩解调方案,并进行了理论分析和性能仿真,最后在FPGA上实现了该方案,相应的测试结果证明了方案的正确性。伪码捕获采用多通道并行伪码相位搜索策略,兼顾了捕获速度和硬件复杂度的要求;在非相干超前滞后延迟锁定环的基础上增加了载波辅助功能,提高了伪码跟踪电路在高动态环境下的适应能力。通过在硬件平台上对接收机方案的性能指标测试,表明提出的方案和实现结果达到了接收机要求指标。更多还原

【Abstract】 Spread Spectrum(SS)communication is a kind of communication system with excellent performance,and has attracted wide attention and interest of researchers since it was born.This dissertation discusses the de-spreading and demodulation of the digital Direct Sequence(DS)BPSK receiver,which will be used in aircraft telemeter,with focus on the techniques of digital down-convert(DDC),fast acquisition and tracking of pseudo noise(PN)sequence etc.This dissertation designs a scheme of de-spread and demodulation about DS-BPSK signal,analyzes its feasibility through simulation,and finally implements it on FPGA.Considering acquisition time and complexity of hardware,phase searching simultaneously in multi-channel,is used in PN acquisition.Then non-coherent delay lock loop aided with carrier tracking,which has good performance of high dynamic range,is chosen to realize the PN tracking.The whole scheme is implemented on FPGA concretely and skillfully.The Despreading module is one of the key techniques in direct-sequence spread-spectrum systems(DSSS).This paper proposes an implementation scheme using FPGA,and also gives the results of simulation after place & route.Debugging results on the hardware confirms the scheme.更多还原