Browsing by Author "Ghasvarianjahromi, Sara"

Now showing 1 - 3 of 3

Metadata only
Simultaneous lightwave information and power transfer in underwater visible light communications
(IEEE, 2019) Ghasvarianjahromi, Sara; Karbalayghareh, Mehdi; Diamantoulakis, P. D.; Karagiannidis, G. K.; Uysal, Murat; Electrical & Electronics Engineering; UYSAL, Murat; Ghasvarianjahromi, Sara; Karbalayghareh, Mehdi
Visible light communication (VLC) has emerged as a high-capacity connectivity solution for underwater sensor networks. Since water is relatively transparent to blue or green light, visible light lasers or LEDs can be used as transmitters for underwater wireless connectivity with data rates up to hundreds of Mbps. In underwater networks, a critical system design issue is the network lifetime which highly depends on the battery capacity. Since recharging in underwater scenarios is typically very costly and impractical, energy harvesting can be considered as a promising alternative. In this paper, we explore simultaneous lightwave information and power transfer (SLIPT) for VLC-based USNs. We adopt time splitting method where the receiver switches in time between the modes of energy harvesting (EH) and information decoding (ID). We derive a closed-form expression for the average harvested energy over log-normal model underwater turbulence channel. Using this expression, we determine the splitting factor between EH and ID operation modes to maximize the harvested energy while satisfying a given bit error rate value.
Metadata only
Simultaneous lightwave information and power transfer in underwater visible light communications
Ghasvarianjahromi, Sara; Uysal, Murat; Uysal, Murat; Durak, Kadir; Karakaya, B.; Department of Electrical and Electronics Engineering; Ghasvarianjahromi, Sara
In this thesis, we investigate simultaneous lightwave information and power transfer (SLIPT) for underwater visible light communication systems. We consider four SLIPT methods namely AC-DC separation (ADS), time switching (TS), power splitting (PS) and time switching-power splitting (TS-PS) where the splitting/switching factors are defined as optimization parameters in TS, PS and TS-PS methods. For each of these methods, we derive closed-form expressions for the average harvested energy, bit error rate and spectral efficiency in the presence of underwater turbulence modeled by lognormal statistics. Using these expressions, we determine the optimal splitting factors to maximize the harvested energy while satisfying a given bit error rate value and a given threshold spectral efficiency value. Our results reveal that, if not optimized, SLIPT methods under consideration are outperformed by the simple AC-DC separation (ADS) method which provides the largest harvested energy versus spectral efficiency (HE-SE) region. Optimization of splitting/switching factors extends the HE-SE regions; hence, optimized versions of TS, PS and TS-PS methods are able to significantly outperform ADS for most cases. We further investigate the effect of various channel and system parameters such as water type, turbulence level, beam divergence, receiver aperture size on the harvested energy and quantify the improvements in battery lifetime through the use of SLIPT methods.
Metadata only
SLIPT for underwater visible light communications: Performance analysis and optimization
(IEEE, 2021-10) Uysal, Murat; Ghasvarianjahromi, Sara; Karbalayghareh, M.; Diamantoulakis, P. D.; Karagiannidis, G. K.; Sait, S. M.; Electrical & Electronics Engineering; UYSAL, Murat; Ghasvarianjahromi, Sara
In this paper, we investigate simultaneous lightwave information and power transfer (SLIPT) for underwater visible light communication systems. We consider three SLIPT methods namely time switching (TS), power splitting (PS) and time switching-power splitting (TS-PS) where the splitting/switching factors are defined as optimization parameters. For each of these methods, we derive closed-form expressions for the average harvested energy, bit error rate and spectral efficiency in the presence of underwater turbulence modeled by lognormal statistics. Using these expressions, we determine the optimal splitting factors to maximize the harvested energy while satisfying a given bit error rate value and a given threshold spectral efficiency value. Our results reveal that, if not optimized, SLIPT methods under consideration are outperformed by the simple AC-DC separation (ADS) method which provides the largest harvested energy versus spectral efficiency (HE-SE) region. Optimization of splitting/switching factors extends the HE-SE regions; hence, optimized versions of TS, PS and TS-PS methods are able to significantly outperform ADS for most cases. We further investigate the effect of various channel and system parameters such as water type, turbulence level, beam divergence, receiver aperture size on the harvested energy and quantify the improvements in battery lifetime through the use of SLIPT methods.