Synthesis of Optimum Chirp Signals for the Time Delay Superresolution

The Cramer-Rao bound for the variances of time delay estimates of two interfering signals is determined. It is shown that in superresolution area the bound depends on algebraic moments of the signal energy spectrum and signal-to-noise ratio (SNR). The bound can be used to find an optimum signal waveform to achieve the potential time delay superresolution. A new methodology is proposed to search for parameters of the polynomial frequency modulation of chirp signals.