卫星移动通信中基于前导的定时同步算法

针对正交频分复用(orthogonal frequency division multiplexing,OFDM)系统中应急数据每帧长度一般为ns级或s级不等,如果无法检测到数据帧的准确到达时刻,便有可能丢失掉整帧数据的问题,提出了一种基于OFDM符号前导的联合检测同步算法(combined detecting synchronization OFDM-based preamble,CDSOP).该算法在利用改进的发送帧前导结构完成粗定时,在粗定时的基础上对接收的数据帧进行细定时,即可完成对OFDM符号定时同步的联合检测.仿真结果表明,在卫星信道环境下,该算法在定时估计标准误差等方面表现出了较好的定时同步性能.

Pilot-based timing synchronization algorithm in satellite mobile communication system

The length of each emergency data frame is generally ranging from milliseconds or seconds, if you can not detect the exact arrival time of the data frame, it is possible to lose the whole data frame. Aiming to the problem, we propose OFDM-based preamble algorithm (Combined Detecting Synchronization OFDM-based Preamble, CDSOP). In this algorithm ,we firstly use the modified preamble structure of the sending frame to complete coarse timing, and then finish fine timing on the basis of the coarse timing for the received data frames. Simulation results show that, the proposed algorithm has good timing synchronization performance in terms of the timing estimate standard error under the satellite channel compared with other algorithms.