Reed-Solomon Coded Probabilistic Constellation Shaping for Molecular Communications

Probabilistic constellation shaping (PCS) is a promising technique employed in molecular communications, utilizing molecular shell mapping (MSM). However, the performance of MSM, particularly its bit error rate (BER), falls short when the exact channel state information is unavailable. To address this challenge and enhance robustness, we propose a scheme known as Reed-Solomon coded PCS (RS-PCS) scheme. This approach combines shaping and coding through a parallel transmitter structure, preserving the shaped distribution at the output of the RS encoder. In addition, we develop a low-complexity receiver that leverages the intra-sequence interference. Our numerical results on BER clearly demonstrate that the proposed RS-PCS scheme outperforms existing schemes that only consider the PCS or RS coding techniques alone.