关键词: PPM，同步捕获，最小二乘，近完美序列

Abstract: A rapid timing acquisition algorithm was proposed in the paper, which is based on least square estimation (LSE),which is developed for UWI3 (ultra-wideband) communication based designed training symbols. Using almost perfect sequcnce,a novel training sequence was judiciously designed. Compared to the conventional algorithm with GHz sample rate, the algorithm can realize timing acctuisition at receiver using simple correlation operations over the samples at the symbol rate(several MHz to several hundreds MHz) , which reduces considerably implementation complexity. The computational efforts of the algorithm is only a third of conventional algorithm. The acquisition performance in the multipath channel was also provided in terms of simulation, which indicates that with a 12-bit training sequences, the scheme achieves a high synchronization performance,when there are 24-bit training sequences,the bit error-rate(I3ER)is close to that of the case with perfect.

Key words: PPM, Liming acquisition, Least square, Almost perfect sequence