中文摘要：

针对TDT（timing with a dirty temple）同步捕获算法只适于脉冲幅度调制（PAM）超宽带（UWB）系统的问题,提出了脉冲位置调制（PPM）下使用Hermite脉冲的基于脏模板（TDT）的同步捕获算法,推导出了PPM调制下接收信号的表达式,分析了接收信号在相邻符号的互相关函数的特点。分析结果表明,在不同于脉冲幅度调制（PAM）的互相关函数,由于PPM调制的非线性,同步参数不能通过互相关函数求期望获得。因此,分析利用正交Hermite脉冲的方法来解决这个问题,采用一串交替的正交Hermite脉冲来调制要发送的信号,并对原TDT算法进行了相应的修改来实现同步,在借助训练序列时,性能更加优越。理论分析和仿真结果表明,该算法结构简单、性能良好、捕获时间短、实现复杂度低。

英文摘要：

Due to the ultra-short information bearing pulses and the low transmitting power,ultra-wideband（ UWB） receiver faces great challenge of timing acquisition. This paper proposed a timing acquisition algorithm with Hermite pulse for pulse position modulation （ PPM ） based on the synchronization criterion termed TDT. It deduced the expression of the received PPM signal,and analyzed the cross-correlation function of nearby symbols. The results show that different from that of PAM,the cross-correlation function of PPM cannot be directly used to acquire timing due to the nonlinearity of PPM. Consequently,the algorithm adopted a train of alternating orthogonal Hermite pulses to modulation the transmitted symbols was proposed for PPMUWB system,which got synchronizing information from the calculating of the difference values of the cross-correlation function. Furthermore,the algorithm could get better performance when using a simple training pattern. Theoretical analysis and simulation results demonstrate that the implementation complexity of the algorithm is low and show performance improvement in terms of the mean square error（ MSE） .