Interference Mitigation-Enabled Signal Detection in Diffusive Molecular Communications Systems With Molecular-Type Spreading

To accomplish complex tasks, several nano-machines may need to communicate via multiple-access channel with one access point, where information fusion is carried out. However, multiple-access diffusive molecular communications (DMC) systems suffer from severe multiple-access interference (MAI) and intersymbol interference (ISI), which should be effectively mitigated at receiver in order to achieve acceptable performance. Built on two fundamental single-user detection schemes, namely, threshold-assisted majority vote detection (TMVD) and equal gain combination detection (EGCD), we first propose three low-complexity interference cancelation schemes, which are the TMVD-assisted iterative interference cancelation (TMVD-IIC), TMVD-based minimum-distance decoding-assisted interference cancelation (TMVD-MDDIC) and the EGCD-assisted
$N$
-order iterative interference cancelation (EGCD-NIIC), for operation in the molecular-type spread-assisted molecular shift keying (MTS-MoSK) DMC systems. Then, following the principle of maximum likelihood (ML) detection, we propose a simplified approximate ML (SAML) detection scheme. The error performance of the MTS-MoSK DMC systems employing, respectively, the considered detection schemes is comprehensively investigated and compared. Furthermore, the complexities of the detection schemes are analyzed and discussed in terms of the complexity-performance tradeoff. Our studies and results show that, compared with the single-user TMVD and EGCD schemes, the proposed interference cancelation schemes are capable of mitigating efficiently the effect of MAI and enabling significant performance improvement at the slightly increased complexity.