摘要
在基于统一载波体制的深空测控通信中,为了有效消除大调制度下的多普勒频偏,提出一种利用频谱对称性、基于圆自卷积的主载波捕获新算法。首先对已下变频的采样信号做FFT变换计算出信号频谱;然后利用圆自卷积法计算出频谱的对称点,即为主载波频率。仿真分析和FPGA验证表明,该算法能够实现各种调制度下的主载波捕获,解决了深空测控通信中大调制度下的多普勒频偏问题。
In deep space telemetry, telecommand and communication（TT＆C） based on universal carrier, a new approach based on circular self-convolution algorithm to eliminating Doppler frequency effectively under large modulation index is proposed, which makes use of symmetrical spectrum for main carrier acquisition. Firstly, the FFT transformation is performed to calculate the signal spectrum after down conversion; then the circular self-convolution algorithm is used to calculate the spectrum symmetrical point, that is, the frequency of main carrier. The simulation and the FPGA demonstration show that this algorithm could realize main carrier acquisition under each kind of modulation index, and has solved the problem of large Doppler frequency deviation under large modulation index in deep space TT＆C communication.
出处
《通信技术》
2010年第1期57-60,共4页
Communications Technology
基金
国家"973"重点基础研究基金项目(批准号:2007CB310600)
国家自然科学基金资助项目(批准号:60532070)
国家863计划(编号:2007AA01z2b3)
关键词
深空测控通信
主载波捕获
圆自卷积
大调制度
deep space TT＆C communication
main carrier acquisition
circular self-convolution
large modulation index
