Partial FFT Demodulation for MIMO-OFDM Over Time-Varying Underwater Acoustic Channels
Recently, the partial Fast Fourier Transform (PFFT) has emerged as a promising demodulation scheme for the orthogonal frequency division multiplexing (OFDM) over underwater acoustic (UWA) channels. However, the effectiveness of OFDM in the receivers is impaired by inter-carrier interference (ICI) due to the significant time variations under UWA channels. In this letter, we consider the weighted-type fractional Fourier transform (WFRFT)-based hybrid carrier (HC) modulation system with PFFT demodulation for UWA communication. The residual ICI, after PFFT demodulation and weight compensation, can be further suppressed in the WFRFT domain. Numerical results are presented to demonstrate the superiority of HC scheme with PFFT demodulation over the single carrier (SC) and OFDM schemes with PFFT demodulation at a very moderate complexity.