多用户DS-UWB信号的伪码周期估计*

在单用户直接序列超宽带(DS-UWB)信号的伪码(PN)周期估计的基础上，采用信号功率谱二次处理的方法，实现了多用户DS-UWB信号的PN码周期盲估计。该方法对接收信号的功率谱进行二次谱处理，最后得到的二次谱就会在接收的多用户DS-UWB 信号的PN码周期整数倍处出现一系列的尖峰脉冲，通过检测这些脉冲的间距就可以得到PN码周期的估计。通过理论推导表明了该方法的可行性，利用计算机仿真，验证了多用户DS-UWB信号在PN码周期的整数倍确实存在二次功率谱的脉冲串，这些脉冲串还具有类似高斯脉冲二次功率谱的形状。同

Blind estimation of PN sequence period for multi-user DS-UWB signals

Based on the blind estimation of pseudo-random (PN) sequence period for single-user DS-UWB signals, this paper used the reprocessing of the power spectrum of signal to ahieve the estimation of PN sequence period for multi-user DS-UWB signal. Firstly, estimated the power spectrum of the received multi-user signals. Secondly, took the estimated power spectrum for input signals and computed its power spectrum again. Finally, a sequence of peak pulses with interval will appear, which equated to the PN sequence period of the DS-UWB signals, and so could accept the estimation of PN sequence period through estimating the intervals. The expression of the reprocessed power spectrum could reveal the feasibility of the method. Then, used computer simulation to prove that the pulse peaks of power spectrum reprocessing really exist in multi-user DS-UWB signal on the location of the integral times of PN sequence period and the shape of every pulse of the pulse train is similar to that of power spectrum reprocessing of the original Gaussian pulse. Computer simulation results also show that the proposed method can work well at lower signal-to-noise ratio.