An Experimental Evaluation of Link Outage Due to Beam Wander in a Turbulent FSO Link

et al. 2023

Int J Communication

The integrated OWC-PON architecture has a potential to overcome the limitations of existent RF technology and eliminate the last mile bottleneck in geographically constrained access networks thus providing real sense broadband from core to user. However, phenomenon such as atmospheric turbulence causes performance degradation in such systems. In the dissemination of multimedia services, the performance is the ultimate quality as perceived by end user's visual senses. To ascertain this quality in quantitative terms, full reference quality metrics are employed for communication purposes. This paper deals with classification, evaluation and analysis of various image quality assessment metrics for image transmission over OWC channel under varying turbulent conditions. The performance enhancement in terms of these metrics is investigated by deploying MIMO diversity reception. Moreover, a prediction model for SSIM is developed and compared for both SISO and MIMO links. The results show an improvement in IQA metrics with diversity reception. SSIM can be predicted in terms of log of refractive index structure parameter by a fourth order polynomial model for both SISO and MIMO receptions under all regimes of turbulence. The goodness of the fit statistics is presented along with the models to provide for their accuracy and reliability.

show abstract

C_{n}^{2} goodbreak= ([], 79 goodbreak\times 10^{- 6} \frac{P}{T^{2}}) C_{T}^{2}

where P and T are the pressure (mbar) and temperature (Kelvin) and

C_{T}^{2}

48 depends upon the temperature gradient. The distribution of irradiance function depends upon the strength of turbulence.…”

Section: Methodsmentioning

confidence: 99%

Analysis of full reference quality metrics for image transmission over a MIMO OWC channel under varying turbulent conditions

et al. 2023

Int J Communication

show abstract

“…Hence, fluctuations in received intensity at optical front end in the receiver section occur. Strength of turbulence is characterized by a constant called refractive index structure parameter C 2 n : 33,34 Typically, C 2 n ranges from 10 À16 for weak turbulence to 10 À13 for strong turbulence.…”

Section: System Designmentioning

confidence: 99%

“…where P and T are the pressure (mbar) and temperature (Kelvin) and C 2 T depends upon temperature gradient. 34 Another significant parameter for a turbulent channel encompassing the strength, wavelength, and propagation distance is Rytov variance. Rytov variance describes severity of turbulence induced scintillation and is defined as 35…”

Section: System Designmentioning

confidence: 99%

“…Hence, fluctuations in received intensity at optical front end in the receiver section occur. Strength of turbulence is characterized by a constant called refractive index structure parameter

C_{n}^{2} .

33,34 Typically,

C_{n}^{2}

ranges from

10^{- 16}

for weak turbulence to

10^{- 13}

for strong turbulence.

C_{n}^{2} = {([], 79 goodbreak\times 10^{- 6} \frac{P}{T^{2}})}^{2} C_{T}^{2}

where P and T are the pressure (mbar) and temperature (Kelvin) and

{normalC}_{normalT}^{2}

depends upon temperature gradient 34 .…”

Section: System Designmentioning

confidence: 99%

“…Strength of turbulence is characterized by a constant called refractive index structure parameter

C_{n}^{2} .

33,34 Typically,

C_{n}^{2}

ranges from

10^{- 16}

for weak turbulence to

10^{- 13}

for strong turbulence.

C_{n}^{2} = {([], 79 goodbreak\times 10^{- 6} \frac{P}{T^{2}})}^{2} C_{T}^{2}

where P and T are the pressure (mbar) and temperature (Kelvin) and

{normalC}_{normalT}^{2}

depends upon temperature gradient 34 . Another significant parameter for a turbulent channel encompassing the strength, wavelength, and propagation distance is Rytov variance.…”

Section: System Designmentioning

confidence: 99%

See 2 more Smart Citations

Quality assessment for terrestrial digital video broadcast over optical wireless communication‐passive optical network under moderately turbulent regime with spatial diversity

et al. 2022

Int J Communication

Self Cite

Summary The preceding decade has seen successful rollout of 5G and convergence of broadcast broadband and telecom sector. The near future bandwidth demands for services such as advanced immersive multimedia are even more challenging. This has led to advent of 6G. The access technologies need to provide virtually unlimited data rates to support majority of applications in 6G. The optical wireless communication (OWC) with its inherent advantages is a potential enabler in this scenario. However, phenomenon such as atmospheric turbulence poses a serious degradation to performance of such systems. For multimedia services, end user perception is the ultimate quality indicator. To ascertain this quality in quantitative terms, full reference quality metrics are employed for communication purposes. In this paper, digital video broadcasting terrestrial (DVB‐T) videos with varying complexities are transmitted over OWC‐passive optical network (PON) architecture. For performance enhancement 2 × 2 repetitive coding MIMO is employed with maximal ratio combining receiver. A total of 6 video quality assessment (VQA) metrics are evaluated for the system w.r.t channel parameter as Rytov variance. For all the VQA metrics, an enhancement in the performance is observed by using MIMO technique. This performance improvement is more prominent for more complex video as compared to less complex video. As for the limiting case BER of 10−3 gives a limiting link distance of 1350 m; however with VQA metrics, the limiting case distance is 1280 m. By the use of 2 × 2 MIMO techniques, this distance enhances by 20–25 m.

show abstract

Performance Analysis of Video Transmission Over OWC-PON in Weak Turbulence Regimes

Proceedings of Third International Conference on Communication, Computing and Electronics Systems

et al. 2022