Table 9 Comparative trade-off analysis of the proposed modulation schemes inUOWC.
Modulation | Type | Spectral Efficiency | Power Efficiency | Complexity | Relevance in UOWC |
|---|---|---|---|---|---|
OOK | Intensity | Low (1 bps/Hz) | High | Very Low | Common baseline; widely used |
PPM | Intensity (Pulse-based) | Low (≤ 1 bps/Hz) | Very High | Low | Preferred in low-power UOWC |
DPSK | Phase | Moderate (2 bps/Hz) | Moderate | Moderate | Robust against phase distortion |
QPSK | Phase | Moderate (2 bps/Hz) | Moderate | Moderate | Balance between capacity and complexity |
32-PSK | Phase | High (> 5 bps/Hz) | Lower | High | Higher spectral efficiency |
64-QAM | Amplitude & Phase | Very High (~ 6 bps/Hz) | Lower | Very High | Benchmarks capacity in clear conditions |
