多普勒频移环境中水声通信伪随机码快速捕获方法

A new PN code acquisition algorithm for underwater communication in high doppler environment

伪随机码应用于水声通信时,需解决接收信号在多普勒频移情况下的快速捕获问题。本文在全数字通讯系统的框架内,提出了基带信号相关检测的数字下移频算法,显著减小了计算量,并针对数字处理的灵活性,提出了多普勒频移的概率搜索策略,根据多普勒频移的分布概率来对其进行搜索,进一步减小多普勒频移搜索的计算量。

It is inevitable that the spread spectrum system of underwater communication will face the difficulty of the PN code acquisition in high Doppler environment. A new approach, which can be used in Software Defined Radio, can reduce the amount of calculation. This approach consists of two parts. One is a new type of DDC (Digital Down Converter) which shifts the signal in the frequency domain and cuts short the length in frequency domain. The other is a probability strategy to reduce the amount of the Doppler shifts searching.