Optical wireless: New enabling transmitter technologies

Smyth, P.P.; Wood, David; Ritchie, S.; Cassidy, S.A.

doi:10.1109/icc.1993.397327

Cited by 16 publications

(7 citation statements)

References 2 publications

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“…In addition a photo-detector with a wide field-of-view normally collects signals that have undergone one or more reflections from ceiling, walls and room objects. Multipath propagation causes ISI because the transmitted pulses spread out in time over alternative routes of differing lengths, limiting the maximum unequalized bit rate R b achievable with a room volume of 10 x 10 x 3 m to typically around 16 Mbit/s [4], [5]. ISI incurs a power penalty and thus bit-error rate (BER) degradation.…”

Section: Introductionmentioning

confidence: 99%

Reducing the effects of intersymbol interference in diffuse DPIM optical wireless communications

Ghassemlooy¹,

Hayes²,

Wilson³

2003

IEE Proceedings - Optoelectronics

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This paper investigates the performance of digital pulse interval modulation (DPIM) in the presence of multipath propagation and additive white Gaussian noise. To combat intersymbol interference (ISI) guard slots and a non-linear equaliser have been introduced. The average optical power requirements (AOPR) due to ISI for cases with/without guard slots and with equaliser are analysed using a ceiling-bounce model. Results obtained show that in the absence of equalisation, DPIM without guard slot offers a lower AOPR compared with on-off keying (OOK). Introducing guard slots gives a further reduction in AOPR by up to 4 dB due to the reduced duty cycle of the DPIM signal. The performance of DPIM without guard slot buy using an equaliser is found to be significantly better than DPIM with guard slots on a channel with severe ISI.

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Section: Introductionmentioning

confidence: 99%

Reducing the effects of intersymbol interference in diffuse DPIM optical wireless communications

Ghassemlooy¹,

Hayes²,

Wilson³

2003

IEE Proceedings - Optoelectronics

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“…It was calculated that this arrangement can cover a table of 4 m length and 2.5 m wide. 17 Article of K. Wang et al describes using of optical fiber ends for optical intensity distribution in room for communication. Concept line of sight was chosen.…”

Section: Free Space Optical Network With Using Optical Fiber As a Trmentioning

confidence: 98%

Software design of segment optical transmitter for indoor free-space optical networks

et al. 2015

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During recent years, there has been rapid development in optical networks. This includes not only fiber optical networks but also free space optical networks. The free space optical networks can be divided into indoor and outdoor ones. The indoor free space optical networks have been experiencing dramatic progress in the last years, allowed by the newest IEEE norm 802.15.7, which enabled development of different types of transmitter receivers, modulation formats, etc. The team of authors is dealing with software design of segment optical transmitters for an indoor free space optical network based on the multi-mode optical 50/125 or 62.5/125 µm fiber. Simulated data are then evaluated from the point of view of optical intensity uniform distribution and space spot light size radiating from segment optical transmitter.

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“…However, the combination of the need for effective short-range indoor wireless connectivity, relative security, and the promise of higher unregulated bandwidth and high data rate at a low cost make the optical wireless link an attractive alternative to radio link [1][2][3][4][5]. Future multimedia applications will demand high data rate and low optical power.…”

Section: Introductionmentioning

confidence: 97%

Indoor optical wireless systems employing dual header pulse interval modulation (DH‐PIM)

Aldibbiat

Ghassemlooy

McLaughlin

2005

Int J Communication

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SUMMARYThis 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-PIM 2 ; with wider pulse duration is the preferred option when the available channel bandwidth is limited and higher optical power is tolerable. Whereas DH-PIM 1 ; 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. M57; DH-PIM 1 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.

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Optical wireless: New enabling transmitter technologies

Cited by 16 publications

References 2 publications

Reducing the effects of intersymbol interference in diffuse DPIM optical wireless communications

Reducing the effects of intersymbol interference in diffuse DPIM optical wireless communications

Software design of segment optical transmitter for indoor free-space optical networks

Indoor optical wireless systems employing dual header pulse interval modulation (DH‐PIM)

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