Improving Doppler Robustness for Optimized Complementary FM Waveform Subsets

In theory, complementary sequences are known to provide no sidelobes in the ideal scenario of zero-Doppler scattering and a distortionless transmitter. Since these conditions are not realistic in practice, a random frequency modulation (RFM) design approach was developed based on the notion of independent complementary subsets, where the FM nature mitigates some of unavoidable transmitter distortion and subset independence facilitates incoherent sidelobe averaging as a backup to complementary cancellation.While this complementary FM approach demonstrated greater resilience compared to theoretical codes (e.g. Golay), it did still only address zero-Doppler. Here, a generalization of that method is developed to enable complementary cancellation over a prescribed Doppler band. Simulation and open-air demonstration of these robust complementary FM waveforms validates that complementary sidelobe cancellation is preserved under Doppler effects.