一种改进的LTE系统下行同步算法

LTE（Long Term Evolution）系统中，作为小区搜索的第一步，符号定时算法需要具备很强的鲁棒性。为了进一步增强现有符号同步算法的抗频偏性能，提出了一种优化的符号同步算法。该算法一方面保持已有分段相关同步算法的优点，同时考虑结合预频偏处理来进行符号定时与粗频偏的联合估计，再将多个相关运算集做叠加处理。理论分析和仿真实验结果表明，在多径信道下，所提算法在完成符号定时和粗频偏估计的同时，大大提高了系统抗频偏性能。

An improved synchronization algorithm for LTE downlink system

In 3GPP Long Term Evolution (LTE) system, symbol timing algorithm, as the first step of cell search, is required a very strong robustness. An improved symbol synchronization algorithm is proposed for further enhancing the performance of anti-frequency-offset of the existing symbol synchronization algorithm. The algorithm keeps the advantages of partial correlation synchronization algorithm, and combines with frequency offset pre-processing to perform timing and coarse frequency offset joint estimation effectively, and then accumulates multiple correlation operation sets. Both the theoretical analysis and simulation results show that the proposed algorithm greatly improves the performance of anti-frequency-offset, while completing the timing and coarse frequency offset estimation under the multi-path channel.