LTE小区搜索中定时与频偏估计算法研究

Research on time and frequency offset estimation algorithm for LTE cell search

在长期演进(LTE)的小区搜索中,定时同步与频偏估计是一个非常重要的同步过程。基于分段相关算法,提出了一种改进算法。利用分段相关算法具有抗频偏的优点结合差分运算,并采用对接收端信号进行累积处理方法,提高了定时同步精度。将本地PSS信号累积相加的结果与接收信号进行相关运算,有效降低了算法的运算量。同时利用本地PSS信号与接收PSS信号的相关性,提出一种有效的频偏估计算法。理论分析与仿真实验表明,与传统算法相比,提出的定时与频偏估计算法有效提高了估计精度,减小了运算量。

In the cell search scheme of Long Term Evolution（LTE）, time and frequency offset estimation is the crucial process in the synchronization procedure. Based on partial correlation algorithm which can combat the frequency offset, it proposes a new symbol timing synchronization algorithm which combines with differential correlation and the method for accumulation of the received signals. The correlation between the sum of three groups of local PSS signals and the received signals is employed which can reduce computational load. An efficient frequency offset estimation algorithm is proposed by using the correlation between local PSS signals and the received signals. Both theory analysis and simulation results show that the proposed algorithm improves the accuracy and reduces the computational load compared to the conventional algorithm.