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对于CDMA系统中序列捕捉的相位搜索策略,当PN序列的相位分布没有任何先验信息时,可采用串行直线搜索策略整个PN序列相位的不定区间;但当能得到相位的分布先验概率时,可以根据先验概率的分布采用适当的搜索策略以缩短捕捉时间,本文的研究表明遵循最大后验概率准则的相位搜索是最佳相位搜索,在此基础上,本文提出了一种基于最大后验概率准则的相位搜索策略,同目前已有的相位搜索策略相比,利用此搜索策略可明显地缩短捕捉时间,提高系统性能,且其适用于任何类型的检测器。文中给出的数值结果表明了该搜索策略具有优越的性能。
For the phase search strategy in CDMA system, when the phase distribution of the PN sequence does not have any prior information, a series of linear searching strategies can be used to search for the indefinite interval of the phase of the PN sequence. However, when the prior probability of the phase distribution is obtained , The appropriate search strategy can be used according to the distribution of prior probabilities to shorten the capture time. The research in this paper shows that the phase search based on the maximum a posteriori probability criterion is the best phase search. On this basis, Compared with the existing phase search strategy, this search strategy can significantly reduce the capture time and improve the system performance, and it is suitable for any type of detector. Numerical results given in this paper show that the search strategy has superior performance.