Raised-Cosine Frequency Domain Pulses for Doppler-Tolerant Radar Ambiguity Functions

Recent ideas for handling doppler in communications such as Orthogonal Time-Frequency Space (OTFS) modulation have explicitly connected to radar concepts through the auto-ambiguity function. Leveraging the OTFS framework, some works have explored signal structure for frequency (but not time) dispersive channels. The resulting systems use a pulse with a flat frequency representation to create a ‘frequency-domain’ cyclic prefix, effectively the time/frequency dual of OFDM. In this paper, we take the pulse structures of those communication signals and explore their potential use as doppler tolerant radar waveforms, with the belief that they can be implemented either approximately, or directly through envelope tracking amplification.