Zero-Padded FDM-FDCP: Real-Time Signal Processing for Underwater Channels

We present an extension of the FDM-FDCP waveform and demonstrate the performance of this waveform in underwater acoustic channels in the presence of AWGN. In this extension, we simply replace the frequency-domain cyclic prefix with guard bands, analogous to zero-padded OFDM. We argue and provide empirical evidence for that this approach in fact improves performance. FDM-FDCP is designed to operate in low-delay, high-Doppler environments; we discuss maximum delay spread that our waveform can tolerate. All modulation and demodulation operations used in this work are accomplished in O(N log N) time complexity, implying that FDM-FDCP is suitable for real-time signal processing in underwater channels.