A time-shift model for OFDM radar

Active and passive detection using CP-OFDM modulated signals traditionally assume that targets do not move significantly during the entire observation period. In this paper, a “time-shift” model that compensates for the motion of targets between pulses during the observation period is introduced. Matched filtering based upon this model can be efficiently performed using a combination of the chirp-z transform and the fast Fourier transform algorithms. The resulting delay-Doppler plots are less “smeary” in the range axis than plots generated when using the traditional techniques over extended observation intervals, allowing better resolution of closely spaced targets.