基于数字匹配滤波器的扩频码捕获技术研究

Research on Technology of Spread Spectrum Code Acquisition Based on Digital Matched Filter

介绍并分析了匹配滤波器扩频码捕获算法的数字实现方式。数字匹配滤波器(Digital Matched Filter,DMF)在扩频码长较长时,耗费的硬件资源较多,实现困难,针对该问题提出了差动解决方案,在不损失性能的前提下大大降低了DMF的硬件复杂度。针对DMF对多普勒频移过于敏感这一缺点,提出了加窗方案,使得其在同一多普勒频移下输出增益衰减较小。通过仿真,证明了改进方案的优越性。

This paper introduces and analyzes the digital implementation method of matched filter. In the condition of longer spread spectrum code,the Digital Matched Filter （DMF） consumes more hardware resource. Aiming at this problem,this paper puts forward an differential solution. By using this solution, the complexity of hardware of DMF can be significantly decreased without performance reduction. Aiming at the problem that DMF is too sensitive to Doppler frequency shift,the windowed solution is proposed to realize the less attenuation of output gain under the same Doppler frequency shift. The simulation results prove the superiority of the improved scheme.