基于导频辅助的定时与载波同步环路设计

Design of data-aided symbol timing and carrier synchronization loop

针对突发通信系统中定时与载波联合同步存在运算复杂度高的问题,提出了一种基于导频辅助的同步算法.首先针对基于匹配滤波器多项实现形式的定时环路,讨论了滤波器的实现形式及各支路采样时钟的控制方法;接着按照最优导频放置方式设计了一种基于相关函数和的频率估计器,该频率估计器运算简单并且其估计精度可接近CRB(Cramer-RaoBound)界;最后用仿真验证了所提出的接收机性能.结果表明新算法采用较小的导频数目就可以实现理想同步,同时复杂度低,适合于工程实现.

Considering the problem of joint symbol timing and carrier estimation with high complexity for burst communication systems,a data-aided synchronization algorithm was proposed.First,the matched filter was implemented by the architecture of polyphase filter bank which avoids the use of interpolation filter.And then,the implementation and control of sample phase in polyphase filter bank was discussed.Second,a carrier synchronization estimator with optimal pilot placement was constructed based on the sum of autocorrelation function of the pilots,whose estimation accuracy can attain Cramer-Rao bound and has a low complexity.Lastly,the simulations were presented to verify the new algorithm performance.The results show the new receiver is easy to realize and can achieve perfect synchronization with a certain amount of pilots.