Abstract: Pedestrians may induce Doppler and micro-Doppler modulations on radar echoes. These Doppler and micro-Doppler signatures extracted from radar echoes could help us to obtain speeds and vibration periods of pedestrians which are of great help to improve detection and identification of human beings. In this paper, an improved human walking model which describes a pedestrian as a linear-rigid target is introduced firstly, and radar echoes of the pedestrian are acquired under the condition of continuous wave (CW) radar signal. Then formulas of instantaneous Doppler of the target are derived and instantaneous Doppler and instantaneous movement signatures of the target are analyzed qualitatively based on the model. Finally, the improved model is verified by open real measurements in Internet, instantaneous signatures of a pedestrian are analyzed by simulation studies with time-frequency transform, and instantaneous movement signatures of the target are extracted from simulation results. The model and signature extraction method discussed in the paper can be extended to calculate radar echoes of other kinds of signals, and can be also adopted in analyzing other movement states of pedestrians.