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Choose a Satellite Channel Model

A satellite communication channel model is a theoretical representation used to simulate and analyze the behavior of satellite communication links under various conditions. Satellite Communications Toolbox provides two types of channel models, radio frequency (RF) channels and optical channels. These models encompass the physical and environmental factors that affect the signal as it travels from the transmitter to the receiver. Each channel model is a System object™.

System objectDescription
etsiRicianChannelMultipath European Telecommunication Standards Institute (ETSI) frequency-flat Rician fading channel
lutzLMSChannelLutz land mobile-satellite (LMS) frequency-flat fading channel
p681LMSChannelITU-R P.681 LMS frequency-flat fading channel
dsocPoissonChannelDeep space optical communication (DSOC) Poisson channel
dsocWebbGaussianChannelDSOC Webb Gaussian or Gaussian channel

RF Channels

Unlike terrestrial wireless communication, where multipath fading due to reflections is a dominant factor, the amplitude and phase of satellite signal are affected by these factors.

  • Atmospheric Conditions — The atmosphere can cause significant signal fading, especially in the higher frequency bands. Specific atmospheric conditions that affect satellite communication include rain fading, clouds and fog, and gaseous absorption.

  • Ionospheric Effects — The ionosphere can introduce fading mostly through scintillation and polarization.

  • Doppler Shift — The relative motion between the satellite and the ground station can cause a Doppler shift in the frequency of the received signal, which can cause fading if the system is not designed to compensate for this effect.

  • Satellite Position — The position of the satellite in the sky relative to the ground station (elevation angle) can affect fading. Low elevation angles can result in longer paths through the atmosphere and potential obstructions, leading to increased fading.

This table describes the various RF channels the toolbox offers and highlights the key differences between them.

Note

These are narrowband channel models, and are applicable for single input single output (SISO) scenarios.

ChannelFrequencyModel TypeFading DistributionSatellite OrbitsLine of Sight ComponentDopplerHas Shadowing
etsiRicianChannel

Typical satellite communications frequency ranges

Single state

Rician

Geosynchronous orbit (GSO)

Yes

Models Doppler spread due to mobile movement

No

lutzLMSChannel

1.54 GHz

Two state semi-Markov

  • Good state — Rician

  • Bad state — Rayleigh with Log-normal

GSO

Yes, for good state only

Models Doppler spread due to mobile movement

Yes

p681LMSChannel

1.5 GHz to 20 GHz

Two state semi-Markov

Loo

GSO and non-geosynchronous orbit (NGSO)

Yes

  • Models Doppler spread due to mobile movement

  • Models Doppler shift on line-of-sight component due to mobile movement

  • Models Doppler shift due to satellite movement

Yes

1.5 GHz to 2.5 GHz

Three state semi-Markov

  • Good state — Nagakami-Rice

  • Moderate state — Loo

  • Bad state — Rayleigh

  • Good state — Yes

  • Moderate state — Yes

  • Bad state — No

Optical Channels

DSOC uses optical (laser) technology for communication between a spacecraft and Earth or between spacecrafts in deep space. Optical communication offers the potential for higher data rates compared to traditional radio frequency (RF) communication systems due to the higher frequencies (and thus shorter wavelengths) of light, which allow for tighter beam divergence and higher bandwidth.

The toolbox offers two DSOC channels and the table highlights the key differences between them.

ChannelInternal Working ModuleDistribution ModelNoise Considerations
dsocPoissonChannel

Models absorbed photons by the ideal photo detectors or ideal photo multiplier tubes (PMT)

Poisson

Only background noise

dsocWebbGaussianChannel

Models photo-electron counts generated at the avalanche photo detector (APD) output in response to the absorbed photons

For Webb-Gaussian channel — combination of WMC (Webb, McIntyre, and Conradi approximation) component and a Gaussian component

Background noise, thermal noise, and surface leakage current

For Gaussian channel — Gaussian

See Also

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