分析了理想功率控制的多用户环境下DS-UWB系统采用串行搜索策略的捕获性能.对于多用户干扰,当干扰用户多时,根据中心极限定理,检测器输出端的多用户干扰可近似为一个高斯随机变量,推导了一定干扰用户下系统检测概率和虚警概率的闭合表达式,在给定的信噪比和一定的捕获门限下,求出捕获时间的均值和方差.数值结果表明,不同数目的多用户干扰下,系统的最佳平均捕获时间近似相同.
The acquisition performance of DS - UWB signal employing the serial acquisition scheme in the multiple access environment under perfect power control is analyzed. For multiple access interference, when the number of interference users is large enough, it is reasonable to model the interference of the output of the detector as a Gaussian random variable by the center limit theory. Thus, the closed - form expression of the detection probability and false alarm probability of the system can be derived under some interference users. Given a fixed SNR and acquisition threshold, we can get the mean and variance of the acquisition time. From the numerical results, we can find the best mean acquisition time of the system is approximately equal under different interference users.