Enhancing deep-sea communication via time-reversal equalization in reliable acoustic path channels

Reliable acoustic path (RAP) channels support stable long-range propagation, but deep-sea communication over RAP is constrained by strong multipath. South China Sea measurements reveal stable arrival structures across multiple source depths, with distinct arrival branches and reverberation tails from scattering at interface inhomogeneities. A RAP-adaptive time-reversal equalizer suppresses multipath by reconstructing the channel impulse response via physics-guided statistical fitting, modeling it as a superposition of discrete multipaths and reverberation. Performance is evaluated using frequency-hopping spread spectrum M-ary frequency-shift keying and direct-sequence spread spectrum M-ary phase-shift keying and quantified with a network-level throughput analysis. Experiments demonstrate reduced inter-symbol interference and improved link reliability, indicating RAP-adaptive time-reversal equalizer as a practical physical-layer method for deep-sea acoustic networks.