摘要
阐述了交替二进制偏移载波(AltBOC)调制技术的基本原理,分析了其调制方式和信号产生方法及调制后信号的频谱特性,与普通BOC调制进行了比较,提出了一种基于Matlab/Simulink环境实现AltBOC调制仿真模型构建的方法,并对每个模块的实现进行了说明,获得了调制后信号的频谱图和星座图。给出了基于VHDL的FPGA调制硬件实现,以及实验测得的调制频谱图、眼图和星座图。研究结果证明仿真方法有效可靠,实验结果与仿真结果吻合好,用FPGA实现E5频段的调制简单易行。
The principle of alternative binary offset carrier (AltBOC) modulation was introduced, and the modulation technology, signal generation method and the modulation power spectrum density were analyzed in this paper. Advantages of AltBOC modulation compared with the BOC modulation were also given out. A method for building the module of AltBOC modulation based on the Matlab/Simulink was proposed. The implementation of each module was presented and the simulated modulation power spectrum density and consellation were gained. A hardware scheme of the modulation based on FPGA, and the measured spectrum density, the eye diagram and the consellation were also presented. The results showed that this simulation method was effective and reliable. The measured results were agreed with the simulated ones well. The modulating the Galileo E5 signal in FPGA was simple and feasible.
出处
《上海航天》
2013年第2期45-50,共6页
Aerospace Shanghai
关键词
卫星导航
AltBOC调制
二进制偏移载波调制
扩频
Satellite navigation
AltBOC modulation
Binary offset carrier modulation
Spread spectrum