Doppler Tolerant and Detection Capable Discrete Frequency-Coding Waveform Sets

This paper introduces discrete frequency-coding waveform (DFCW) sets designed by digitizing the instantaneous frequency of linear FM (LFM) waveform-based code sets. The DFCW sets are based on frequency-shifted LFM sets. It is shown that the entire DFCW set can be received using a smart extended matched filter, constructed by extending the instantaneous frequency on either side and can detect the higher energy distribution within the filter before summation (i.e., the Hadamard product). This higher energy distribution location determines the frequency shift, which could identify a particular member of the DFCW set or the Doppler shift of a DFCW based on the LFM waveform. The result is Doppler detection of an LFM based DFCW or detection of a particular member of the DFCW set. The frequency offset between the different members of the set is chosen to enable the detection of Doppler shifts of the individual code members. It is shown that such good code sets could be constructed by digitizing the instantaneous frequency of up-chirps of varying slopes, where a bank of extended matched filters would be required, one for each slope. Such Doppler tolerant and detection capable DFCW sets find utility in digital MIMO radar and orthogonal netted radar systems.