密集多径信道下超宽带信号捕获方法的分析

Analysis of acquisition for UWB over dense multipath channel

在不考虑虚警的假设下,重点推导了几种捕获方法完成捕获所需的平均搜索次数,特别考虑了搜索单元数N和多径数K的情形,并进一步分析了各方法的优缺点。通过比较可知K步跳变法是所有搜索方法中最优的,但由于此方法要预先知道K的值,使其不可行,而比特翻转法和折半法在一些情况下虽然只是近似最优,但在实际中却是可行的。比特翻转法在使用时有一定限制条件,而新提出的折半法却适用于任何情况,因而不失为一种好的捕获方法。

In this paper,the authors analyze the rapid acquisition of UWB signals in the dense multipath channel. The performance of several algorithms is deduced and disadvantages are pointed out. The analysis shows that the optimal search strategy is a simple ＂Jump-by-K＂ structure. However, the number of multipath K must be clear in advance, so it isn＇t practicable. Although the bit-reversal search and reduce-by-half search are no good than the Jump-by-K, it＇s practicable. Bit-reversal search has some restrictions while reduce-by-half search can work in arbitrary conditions,so the reduce-by-half search is a very excellent search algorithm.