Multicarrier Communication Over Underwater Acoustic Channels With Nonuniform Doppler Shifts

Underwater acoustic (UWA) channels are wideband in nature due to the small ratio of the carrier frequency to the signal bandwidth, which introduces frequency-dependent Doppler shifts. In this paper, we treat the channel as having a common Doppler scaling factor on all propagation paths, and propose a two-step approach to mitigating the Doppler effect: 1) nonuniform Doppler compensation via resampling that converts a "wideband" problem into a "narrowband" problem and 2) high-resolution uniform compensation of the residual Doppler. We focus on zero-padded orthogonal frequency-division multiplexing (OFDM) to minimize the transmission power. Null subcarriers are used to facilitate Doppler compensation, and pilot…

• NS
  National Science Foundation

  Award: 0725562
• OO
  Office of Naval Research

  Award: N00014
• DO
  Division of Electrical, Communications and Cyber Systems