Abstract
This paper assesses the performance of dual header pulse interval modulation (DH-PIM) over indoor optical wireless systems. DH-PIM being anisochronous scheme offers a built-in symbol synchronization capability. Theoretical and simulation results demonstrate that DH-PIM offers shorter symbol length, improved transmission rate and bandwidth requirement and a comparable power spectral density profile compared with digital pulse interval modulation (DPIM) and pulse position modulation (PPM) schemes.
It is shown that DH-PIM2, with wider pulse duration is the preferred option when the available channel bandwidth is limited and higher optical power is tolerable. Whereas DH-PIM1, with narrower pulse width, exhibits comparable power requirements but a marginally higher bandwidth compared with DPIM, and is also more bandwidth efficient than PPM at the cost of increased power requirement. However, at higher bit resolutions, i.e. M⩾7, DH-PIM1 is both bandwidth and power efficient compared with PPM. Error rate analysis show that DH-PIM offers improved packet error rate compared with on-off-keying (OOK) and DPIM, but marginally inferior as compared with PPM. The power requirement and penalty due to intersymbol interference for non-dispersive and dispersive channels is analysed and the results show that for given parameters, DH-PIM requires marginally higher optical power compared with PPM and DPIM, but it supports the same bit rate at much less bandwidth requirement.
Original language | English |
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Pages (from-to) | 285-305 |
Journal | International Journal of Communication Systems |
Volume | 18 |
Issue number | 3 |
DOIs | |
Publication status | Published - Apr 2005 |
Keywords
- optical wireless communications
- pulse interval modulation
- packet error rate
- optical power requirement
- bandwidth requirement
- multipath dispersion