2D Sinc Interpolation-Based Fractional Delay and Doppler Estimation Using Time and Frequency Shifted Gaussian Pulses

An accurate delay and Doppler estimation method for a radar system using time and frequency-shifted pulses with pseudo-random numbers is proposed. The ambiguity function of the transmitted signal has a strong peak at the origin and is close to zero if delay and Doppler are more than the inverses of the bandwidth and time-width. A two-dimensional (2D) sinc function gives a good approximation of the ambiguity function around the origin, by which fractional delay and Doppler are accurately estimated.