Gradient-Based Optimization of Pseudo-Random PRI Staggering

Pulse repetition interval (PRI) staggering is known to provide expansion of unambiguous Doppler. Random PRI staggering provides further diversity since each stagger sequence can be unique, though doing so tends to incur higher Doppler sidelobes. Expanding on recent work where the Doppler response is posed as a function of the sequence of continuously-parameterized stagger values, here the formulation of a gradient-based optimization framework is shown to flatten the response over a prescribed extended Doppler interval when applied to arbitrary random stagger sequences. A metric for uniqueness between PRI sequences is also examined. Both simulated and open-air measurements demonstrate that optimization significantly improves peak sidelobe performance while maintaining uniqueness of the random instantiation (i.e. does not collapse to a single solution).