Propagation and Channel Models

Site and terrain visualization, propagation model specification (including Longley-Rice), signal strength, signal coverage maps, and static and fading channel models

RF path propagation modeling describes the behavior of electromagnetic radiation from a point of transmission as the signal travels through the surrounding environment. Model RF propagation paths and visualize them in 3-D.

Channel modeling describes the over-the-air environment in communications system links. Analysis of propagation and channel modelling is essential in understanding how electromagnetic waves incur losses from a transmitter to a receiver in different scenarios. Model and visualize noisy SISO and MIMO channels that have Rayleigh, Rician, or WINNER II fading profiles. Atmospheric impairments and multiple Doppler spectrum shapes are also available.

Functions

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RF Propagation

Map Data

`addCustomBasemap`	Add custom basemap
`addCustomTerrain`	Add custom terrain data
`removeCustomBasemap`	Remove custom basemap
`removeCustomTerrain`	Remove custom terrain data

Site

`show`	Show site in Site Viewer
`hide`	Hide site from Site Viewer
`distance`	Distance between sites
`angle`	Angle between sites
`elevation`	Elevation of site
`location`	Coordinates at distance and angle from site

Propagation and Visualization

`coverage`	Display or compute coverage map
`pattern`	Display antenna radiation pattern in Site Viewer
`sinr`	Display or compute signal-to-interference-plus-noise (SINR) ratio
`link`	Display or compute communication link status
`sigstrength`	Received signal strength
`raytrace`	Display or compute RF propagation rays
`los`	Display or compute line-of-sight (LOS) visibility status
`propagationModel`	Create RF propagation model
`pathloss`	Path loss of radio wave propagation

Path Loss

`cranerainpl`	RF signal attenuation due to rainfall using Crane model
`rainpl`	RF signal attenuation due to rainfall
`gaspl`	RF signal attenuation due to atmospheric gases
`fogpl`	RF signal attenuation due to fog and clouds
`fspl`	Free space path loss
`raypl`	Path loss and phase change for RF propagation ray
`buildingMaterialPermittivity`	Permittivity and conductivity of building materials
`earthSurfacePermittivity`	Permittivity and conductivity of earth surface materials

Channel Models

Channel Modeling

`awgn`	Add white Gaussian noise to signal
`bsc`	Binary symmetric channel
`convertSNR`	Convert SNR values
`stdchan`	Construct channel System object from set of standardized channel models

WINNER II Channel

`winner2.AntennaArray`	Create antenna array
`winner2.dipole`	Calculate field pattern of half-wavelength dipole
`winner2.layoutparset`	WINNER II layout parameter configuration
`winner2.wim`	Generate channel coefficients using WINNER II channel model
`winner2.wimparset`	WINNER II model parameter configuration

Doppler Characteristics

doppler Construct Doppler spectrum structure

Coordinate System Transformations

`rangeangle`	Range and angle calculation
`global2localcoord`	Convert global to local coordinates
`local2globalcoord`	Convert local to global coordinates
`cart2sphvec`	Convert vector from Cartesian components to spherical representation
`sph2cartvec`	Convert vector from spherical basis components to Cartesian components

Objects

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RF Propagation

Sites

`txsite`	Create RF transmitter site
`rxsite`	Create RF receiver site
`siteviewer`	Create Site Viewer
`arrayConfig`	Create phased array configuration

Propagation Models

`FreeSpace`	Free space propagation model
`Rain`	Rain propagation model
`Gas`	Gas propagation model
`Fog`	Fog propagation model
`CloseIn`	Close-in propagation model
`LongleyRice`	Longley-Rice propagation model
`RayTracing`	Ray tracing propagation model

Propagation Data

`propagationData`	Create RF propagation data from measurements
`comm.Ray`	Create RF propagation ray

Channel Models

`comm.AWGNChannel`	Add white Gaussian noise to input signal
`comm.RayTracingChannel`	Filter signal through multipath fading channel defined by propagation rays
`comm.RayleighChannel`	Filter input signal through multipath Rayleigh fading channel
`comm.RicianChannel`	Filter input signal through multipath Rician fading channel
`comm.MIMOChannel`	Filter input signal through MIMO multipath fading channel
`comm.WINNER2Channel`	Filter input signal through WINNER II fading channel
`comm.gpu.AWGNChannel`	Add white Gaussian noise to input signal with GPU
`comm.ChannelFilter`	Filter signal using multipath gains at specified path delays
`comm.ThermalNoise`	Add thermal noise to signal

Blocks

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Path Loss

Free Space Path Loss

Apply free space path loss to complex signal

Channel Models

AWGN Channel	Add white Gaussian noise to input signal
SISO Fading Channel	Filter input signal through SISO multipath fading channel
MIMO Fading Channel	Filter input signal through MIMO multipath fading channel
Binary Symmetric Channel	Introduce binary errors

Topics

RF Propagation

Choose a Propagation Model
When to use the different propagation models based on frequency, type, and limitations.
RF Propagation and Visualization
Visualize coverage maps, SINR maps, and propagation paths in outdoor and indoor environments.
Ray Tracing for Wireless Communications
Ray tracing models predict propagation paths and corresponding losses using 3-D environment geometry and electromagnetic analysis.

Channel Modeling

AWGN Channel
Model channel and RF impairment characteristics.
Configure Eb/No for AWGN Channels with Coding
This example shows how to set the bit energy to noise density ratio (Eb/No) for communication links employing channel coding.
Using AWGN Channel Block for Coded Signals
Two links perform error control coding on a signal that has passed through an impairment channel.
Fading Channels
Defining a fading channel object and applying it to a signal.
Channel Visualization
These channel modeling System objects and blocks in Communications Toolbox™ include an option to visualize the characteristics of a fading channel.
WINNER II Channel
Model the WINNER II channel using the WINNER II Channel Model for Communications Toolbox add-on.

Featured Examples

Indoor MIMO-OFDM Communication Link using Ray Tracing

Perform ray tracing in an indoor environment and use the results to build a channel model for a link level simulation with the MIMO-OFDM technique.

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Visualize Antenna Coverage Map and Communication Links

Calculate and visualize signal strength between a transmitter and multiple receivers. The visualizations include an area coverage map and colored communication links. The example also shows selection of a directional antenna in order to achieve a communication link to a specific location.

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Urban Link and Coverage Analysis Using Ray Tracing

Use ray tracing to analyze communication links and coverage areas in an urban environment. Within the example:

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GSM, CDMA and WiMAX Channel Models

Simulate multipath fading channels defined for GSM/EDGE [ 1 2 ], CDMA [ 3 ], and WiMAX [ 4 ] wireless standards. The example uses the Rayleigh and MIMO fading channel System objects™ from Communications Toolbox™ to simulate and visualize the channels.

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Multipath Fading Channel

Use Rayleigh and Rician multipath fading channel System objects and their built-in visualization to model a fading channel and display the spectral characteristics of the channel. Rayleigh and Rician fading channels are useful models of real-world phenomena in wireless communication. These phenomena include multipath scattering effects, time dispersion, and Doppler shifts that arise from relative motion between the transmitter and receiver.

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Multipath Fading Channel in Simulink

How to use the SISO Fading Channel block from the Communications Toolbox™ to simulate multipath Rayleigh and Rician fading channels, which are useful models of real-world phenomena in wireless communications. These phenomena include multipath scattering effects, time dispersion, and Doppler shifts that arise from relative motion between the transmitter and receiver. The model also shows how to visualize channel characteristics such as the impulse and frequency responses, Doppler spectrum and component gains.

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HF Ionospheric Channel Models

Simulate High-Frequency (HF) ionospheric channels, based on the models described in Recommendation ITU-R F.1487. In particular, it shows how to simulate the general Watterson channel model, and other simplified channel models used in the quantitative testing of HF modems. It makes use of the comm.RayleighChannel System object™ and stdchan function along with the Gaussian and bi-Gaussian Doppler structures from Communications Toolbox™.

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Simultaneous Simulation of Multiple Fading Channels with WINNER II Channel Model

Set up a system with multiple base stations (BS), multiple mobile stations (MS) and multiple MIMO downlinks from one BS sector to one MS. You must download and install the WINNER II Channel Model for Communications Toolbox™ Add-On to run this example. Each link is assigned with a propagation scenario and condition. Fading channel coefficients for all links are generated simultaneously. An impulse signal is passed through the fading channel for each link. The received impulse and frequency responses are plotted for selected links.

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802.11ac Multiuser MIMO Precoding with WINNER II Channel Model

The transmit and receive processing for a 802.11ac™ multiuser downlink transmission over a WINNER II fading channel. You must download and install the WINNER II Channel Model for Communications Toolbox™ Add-On to run this example. Only one WINNER II channel System object™ is needed to set up the channels from one access point to all users.

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Adjacent and Co-Channel Interference

This model uses PSK-modulated signals to show the effects of adjacent and co-channel interference on a transmitted signal. You can view the effect of adjacent channel interferer and co-channel interferer together or individually.

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