数字通信中的多普勒频偏估计技术研究，采用开环大频偏估计算法，调制是4/pi_DQPSK-Doppler shift estimation in digital communications technology, the use of open-loop large frequency offset estimation algorithms, modulation is 4/pi_DQPSK

用于实现多普勒频移和时延的估计，是基于离散信号的频域周期性实现的。-jiontly doppler and delay estimation based on ambiguity function

frft用于线性调频信号多普勒调频率估计-frft transform for doppler frequency rate estimation