A Receiver for Multicarrier Logarithmic Warped Frequency Domain Code Waveforms

This paper studies a receiver for a new class of waveforms created by mapping an existing digital radar code onto set of simultaneously transmitted frequencies that are uniformly spaced after a logarithmic warping of the frequency axis. This mapping preserves the digital code's autocorrelation mainlobe and sidelobes while adding Doppler detection capability. The receiver uses a running Chirp Z-Transform followed by frequency warping and convolutional matched filtering in the warped frequency domain to detect the incoming waveform. Noise and interference between the warped domain code elements are suppressed via a bank of bandpass filters. This paper gives an example of these waveforms, derives the optimal matched filter threshold, illustrates its performance, and exhibits the time and Doppler resolution capability of the receiver.