摘要
针对卫星遥测体制下低信噪比、大频偏载波捕获速度慢的情况,提出了一种基于FFT载波捕获方法。根据载波的频域幅值特性,采用FFT频率估计法和扫频法相结合,使载波在较低信噪比、大频偏的情况下被快速、准确捕获,解决了数据速率连续可调的大频偏情况下的载波捕获问题。利用Xilinx Vertix4系列FPGA芯片在系统时钟为110 MHz时对文章提出的方法进行验证。结果表明,该方法载波捕获精度高,系统稳定可靠。此方法已成功应用于卫星模拟测试站中。
A method of carrier acquisition is proposed in this paper for improving the capture speed in the satellite telemetering systems even if the system has low SNR and large frequency offset. Based on the frequency amplitude characteristic of the residual carrier, by using the method of frequency domain search, FFT frequency estimation combined with the frequency sweep method, the carrier in the low signal-to-noise ratio, large frequency offset can be quickly and accurately capture, and the problem that carrier acquisition in data rate continuously adjustable and large frequency offset limit can be solved . The method proposed to using Xilinx Vertix4 FPGA in 110MHz system clock is verified .The results show that the carrier acquisition of high precision, stable and reliable system .The method has been successfully applied to the satellite simulation test station.
出处
《电子设计工程》
2017年第5期103-106,共4页
Electronic Design Engineering
关键词
卫星遥测
FFT
载波捕获
信噪比
频偏
satellite telemetering
FFT
carrier acquisition
SNR
frequency offset
