卫星发射与地面接收信号位同步算法仿真研究

Investigation on the Bit Synchronization Algorithm Simulation of the Satellite Launching And Receiving Signal

针对卫星接收信号位同步问题传统算法无法满足卫星与地面之间越来越高的实时传输要求,特别由于目前急剧增加的数据量更无法解决上述问题。提出依据全数字接收机的原理,运用选择控制逻辑的方式,在matlab/simulink中搭建了位同步仿真模型。设计并实现了一种Farrow结构的插值滤波器与Gardner定时误差检测算法的QPSK调制基带信号位同步系统。仿真结果显示,相对于传统插值算法,减少了运算量并提高了位同步系统的性能,并且在加入频率偏移的情况下,具有更好的同步精度和较快的收敛速度。结果为高速全数字接收机中位同步优化设计实现提供了参考。

In view of the higher demand of real-time transmission between the satellite and the ground, the traditional bit synchronization algorithm may not satisfy the enormous amount of data calculation. Based on the basic theory of all-digital receiver, we built a bit synchronization simulation model based on the method of selective control logic with Matlab/Simulink. In this paper, we designed and implemented a bit synchronization system of QPSK modulation baseband signal based on Farrow structure interpolator and Gardner timing error detection algorithm. Simulation resuits show that compared with traditional interpolation algorithm, the new interpolation controller can reduce the calculating amount of the traditional algorithm. Meanwhile, it proves the performance of bit synchronization system. The bit synchronization system has a better synchronization precision and faster convergence speed under the circumstance of frequency offset. The result provides a reference for the implementation of the bit synchronization module in high speed all-digital receiver.