DS—CDMA伪随机码的捕捉时间

The catching time of PN code for DS-CDMA

分析了扩频伪随机码的捕捉过程,建立了捕捉时间与正确检测概率、虚警概率、积分时间等变量的函数关系。根据直接序列扩频通信的仿真模型,研究了单径信道与多径信道、静止信道与衰落信道情形下捕捉时间的差异,以及匹配滤波器输出指标变化对捕捉时间的影响。结果表明:在正确检测概率相对较低时静止信道能获得较好的捕捉性能,且单径信道比多径信道捕捉时间值小;而在慢衰落信道中,多径信道的捕捉性能较好。

This paper analyzes the process of the PN code catching for DS-CDMA communication system. Functional relationships between catching time, correct probabilities for detection, error probabilities for warning and integral time are established. It discusses the differences of catching time under the situation such as single-path channel vs multi-path channel, stationary channel vs fading channel, and the effect on catching time from the change of matching filter's export. The result shows that better performance of catching can be gained in stationary channel when correct probabilities for detection is relatively low, and single-path channel uses less time than multi-path channel. But the performance of catching in multi-path channel is better in fading channel.