Exact Analysis of SIR Performance for the Mobile OFDM Communication Systems Over the Underwater Acoustic Channel

ABSTRACT Orthogonal frequency division multiplexing (OFDM) serves as a fundamental waveform in mobile high‐speed underwater acoustic (UWA) communication scenarios. However, the large sidelobe energy of its sub‐carriers leads to significant performance degradation when subjected to the large‐scale UWA non‐uniform Doppler effects caused by relative motion between transceivers. To quantitatively assess the impact of the UWA Doppler effects on the mobile OFDM UWA communication systems, we derive a closed‐form analytical expression for the signal‐to‐interference ratio performance by integrating the effects of distortion and non‐uniform Doppler shifts in the UWA channel. The simulation results corroborate the theoretical computations derived from the expression, exhibiting substantial predictive precision across various UWA Doppler shift scales.