Aiming at the acquisition problem of direct sequence spread-spectrum (DSSS) signals with large Doppler offset, a new method based on fast Fourier transform (FFT) is proposed.

This might include moving them a little further from an open window (just outside the direct rays), or aiming your flash at a nearby wall or ceiling.

Aiming at the control accuracy of rotational speed resulting from direct current speed regulation system, a direct current speed regulating system depending on CNC is proposed.