Abstract
Different modulation methods for optical wireless have different power and bandwidth efficiencies. Each approach has a direct bearing on the quality and effectiveness of wireless optical communications. As two prime examples, pulse position modulation (PPM) and pulse width modulation (PWM) are compared. The comparison includes the power and bandwidth efficiencies, the power spectrum distribution, and the ability to resist intersymbol interference. Compact system models of multilevel digital PPM (L-PPM), and multilevel digital PWM (L-PWM) are also introduced. The results show that L-PPM has advantages in power efficiency and an approximately uniform spectral distribution, whereas L-PWM has a greater ability to resist intersymbol interference.
| Original language | English |
|---|---|
| Article number | 065001 |
| Journal | Optical Engineering |
| Volume | 46 |
| Issue number | 6 |
| DOIs | |
| State | Published - Jun 2007 |
Keywords
- Bandwidth efficiencies
- Intersymbol interference
- Power efficiencies
- Pulse position modulation
- Pulse width modulation