Generalized Molecular-Shift Keying (GMoSK): Principles and Performance Analysis

A generalized molecular-shift keying (GMoSK) modulation scheme is proposed for supporting diffusive molecular communication (DMC). Instead of activating one type of molecules in the traditional molecule shift keying (MoSK) modulation, GMoSK simultaneously activates several types of molecules, with the objective to increase data rate and the potential to further mitigate inter-symbol interference (ISI) beyond MoSK. For signal detection in the GMoSK-modulated DMC (GMoSK-DMC) systems, we first derive a symbol-based idealized maximum likelihood (IML) detector, from which we then deduce two practical detection schemes, namely, the zero-level decision feedback maximum likelihood (ZDF/ML) detector and the one-level decision feedback maximum likelihood (1DF/ML) detector. The error performance of the GMoSK-DMC systems with the IML- and ZDF/ML-detectors is mathematically analyzed. Furthermore, the error performance of the GMoSK-DMC systems with our proposed detection schemes is investigated and compared, which is also compared with that of the DMC systems employing the legacy MoSK modulation, the binary concentration shift keying (BCSK) modulation, the depleted MoSK (D-MoSK) modulation, and the Molecule-as-a-Frame (MaaF) modulation. Our studies and performance results demonstrate that GMoSK has the potential to achieve the performance beyond the above four modulation schemes, and employs the merit of high-flexibility for attaining relatively high data rate and also for ISI mitigation.