摘要
当无人机处在任务路径末端,或者受到电波传输环境和电磁干扰的影响,数据链接收端信号将变为低信噪比信号,用于载波提取的锁相环性能严重下降或失锁。因此,为了保证无人机顺利完成预定任务,低信噪比信号的载波恢复成为无人机数据链的关键技术之一。本文从循环谱的基本概念出发,研究并给出了BPSK调制信号的循环谱密度函数。重点介绍了基于时域平滑FFT累加算法的循环谱计算机仿真实现方法,并利用该方法,验证了在信噪比为-10dB条件下,循环谱依旧可以准确的对信号的载波频率进行估计。
When UAV works on the end of the task path, or affected by waves transmission environment and the influence of the electromagnetic interference, the signal of receiver will be made low signal-to-noise ratio （SNR） signal and the PLL using for carrier extraction will performance serious decline or loss locks. Therefore, in order to ensure UAV completed a predefined task successfully, low SNR carrier recovery has become one of the key technologies in the UAV data chain. In this paper, based on the basic concept of cyclic spectral, we research and give the cyclic spectral density function of the BPSK modulation signal. We emphasis a computer simulation method based on the time-smoothing FFr accumulation method and use this method to verify cyclic spectral is still effective to estimate the carrier frequency when the SNR is -10 dB.
出处
《电子设计工程》
2013年第11期97-100,共4页
Electronic Design Engineering
基金
总装预研基金(9140A25030511HK03)
西北工业大学研究生创业种子基金(Z2012088)
关键词
低信噪比
循环谱
BPSK
时域平滑FFT累加算法
low signal-to-noise radio
cyclic spectrum
BPSK
the time-smoothing FFT accumulation method
