Polar-turbo equalization in orthogonal frequency division multiplexing for underwater acoustic communications

Orthogonal frequency division multiplexing (OFDM) is known to be an effective technique to overcome frequency-selective fading caused by multipath propagation and Doppler effect. OFDM divides the transmitted signal into multiple narrowband subcarriers, significantly reducing the negative impact of fading across the frequency spectrum. To improve the reliability and performance of OFDM systems, polar codes, introduced by Erdal Arıkan in 2008, are applied in underwater communications. Another approach is to use the polar-turbo equalization which the equalizer and polar decoder are connected through interleaver and de-interleaver recursively updating each other's information. We propose a model that combines with polar-turbo equalization in OFDM systems. Proposed polar-turbo equalization in OFDM effectively mitigates performance degradation caused by frequency-selective fading and enhances communication reliability in underwater environments. [This research is supported by KRIT grant funded by the Korean government (DAPA) (KRIT-CT-23-035-01, Multi AUV operation Technology for Mine Detection ('23–'28))]