Parameter estimation of hybrid hyperbolic FM and polynomial phase signals using the multi-lag high-order ambiguity function

Parameter estimation for a combination of a polynomial phase signal (PPS) and a hyperbolic frequency modulation (FM) is addressed. A novel approach is proposed that allows one to decouple estimation of the FM parameters from that of the PPS, exploiting the properties of the multi-lag high-order ambiguity function (ml-HAF). The accuracy achievable by any unbiased estimator of the hybrid FM-PPS parameters is investigated by means of the Cramer-Rao lower bounds (CRLB). Performance analysis is carried out and the CRLBs are compared with simulation results.