【摘要】 本文提出了一种基于多天线辅助估计的UWB(超宽带)快速捕获算法,利用UWB信号的循环平稳特性,将接收信号与它自身延迟一个信息位产生的模板相关,应用最大似然方法就可得到一个粗略的同步时间估计,在充分利用线性天线阵空间分集增益的情况下,这种估计相当准确。在此基础上继续进行精确同步,直到捕获任一符号位的第一帧第一个到达脉冲。文中采用流图法给出了本算法平均捕获时间的闭式解。理论分析和计算机模拟表明,该算法与同等硬件复杂程度和同等捕获精度的其他捕获方法相比可明显地缩短平均捕获时间。更多还原

【Abstract】 A rapid timing acquisition scheme with multiple antennas is proposed for Ultra Wideband(UWB)signals,in which coarse estimation of initial frame is obtained in this paper based on Cyclostationarity(CS)inherent to UWB signals.We develop a data- aided approach to correlate the received waveform with the template taken from received signals a symbol earlier to get the estimation based on the maximum likelihood(ML)criterion.Through utilizing spatial diversity from multiple antennas to improve system perform- ance,the results of coarse estimation are very precise.After finishing coarse acquisition,fine synchronization works until finding the signal with maximum energy among all received signals.The performance of the proposed acquisition scheme is analytically evaluated in terms of the mean acquisition time,which is derived by the generating function flow graph technique.Analysis in theory and numerical results show that the proposed scheme can drastically reduce the mean acquisition time for UWB signals in a dense multi-path environ- ment,compared with the schemes with the same hardware complexity and in the same synchronization precision.更多还原