摘要
提出了利用DSP进行辅助捕获的PN码快捕实现新方法。利用DSP强大的数据处理能力,通过软件算法估计出接收信号和本地产生PN码信号的相对时延,指导串行搜索系统从接收信号最可能的相位位置附近开始搜索,从而达到快捕的目的。实验结果表明:通过DSP器件进行辅助捕获,不仅能在很短的时间内完成PN码的捕获;同时,通过对“超前码片数”置不同的值,可以很方便地控制串行捕获电路从开始捕获到完成捕获所需的捕获时间。
We propose a new scheme for rapid acquisition of PN signals in direct sequence spread spectrum （DS/SS） systems by estimating the phase of the received PN signal with the application of a DSP. The phase of the incoming PN signal is estimated using the time domain correlation between the PN signal and the local PN sequence utilizing DSP. True phase alignment is detected using a conventional in coherent serial search scheme, where the initial phase of the local PN generators is set to a value obtained by the DSP. The performance of the proposed acquisition scheme is evaluated in terms of the acquisition time. The results show that the proposed scheme can achieve acquisition faster than the conventional scheme in nominal operating condition.
出处
《全球定位系统》
2005年第6期27-29,42,共4页
Gnss World of China
关键词
DSP
伪随机码
串行捕获
辅助捕获
捕获时间
DSP
PN code
serial acquisition
auxiliary acquisition
acquisition time.
