摘要
针对基于北斗信号的星载双站SAR成像频率同步误差,提出一种在高噪声情况下新的频率同步方法。以北斗卫星直达波信号为同步信号源建立同步通道,使用单周期积累的扩频信号优化时频捕获算法得到较精确伪码时延,在码同步后使用已知时延的多周期积累的时频捕获算法获到频率误差。连续10次计算机仿真在SNR=-50db的高噪声环境下频率误差均不超过1.5Hz。
In view of the frequency synchronization error to the star-star bistatic SAR imaging with signal of COMPASS Navigation Satel ite System （CNSS）, a novel frequency synchronization method for strong noise environment was presented. A synchronizing channel was constructed with the direct wave of CNSS as the signal source for synchronization. The high accuracy pseudo-random code delay can be got by capture algorithm of the time-frequency optimization in single period . then, base on the synchronization of pseudo-random code , the frequency synchronization error can be got by capture algorithm of the time-frequency with Multi period accumulation. The frequency synchronization errors are less than 1.5Hz in 10 computer simulations with strong noise as SNR=-50db.
出处
《中国新通信》
2015年第1期102-103,共2页
China New Telecommunications
关键词
北斗信号
频率同步
高噪声
多周期积累
signal of CNSS
frequency synchronization
strong noise
Multi period accumulation
