一种基于差分匹配滤波的高效捕获算法

扩频接收机系统中,载波的捕获是衡量系统性能的重要指标。当系统接入多路叠加并行信号时,若需要在二维对信号进行捕获,所需捕获时间、所耗资源和接收机功耗将成倍增加。文中针对此问题,提出了一种基于差分滤波器的分集接收方案,大幅降低了系统资源的占用,从而减少了功耗、成本和捕获时间。利用伪随机码的双极性和差分滤波结构减少了所用加法器的数量,并结合对伪随机码并行分集的结构,在多路中对滤波结果进行复用。通过对传统快速相关捕获算法、快速捕获算法、频率相关法以及文中基于差分滤波的并行分集结构进行了复杂度对比。其结果显示,基于差分滤波的并行分集结构在节省资源、提高效率上均具有较大优势。

An Efficient Algorithm for Acquisition Based on the Differential Digital Matched Filter

Frequency acquisition is an important indicator of system performance of the spread spectrum receiver. Much more captured time and additional resources are required when the received signal that is a combination of several signals. The paper introduces the application of the differential digital matched filter in the spread spectrum communication systems. A multipurpose receiver architecture for acquisition based on the differential digital matched filter is proposed. A two-dimensional search method for Doppler frequency and code phase is converted into one-dimensional search approach for Doppler frequency. The correlation structure in the spread spectrum communication systems is developed, which proves much superior in saving resources and improving efficiency to conventional ones.