# info

Characteristic information of link-level MIMO channel

## Description

returns characteristic information of the link-level multi-input multi-output (MIMO) channel
model, `channelInfo`

= info(`channel`

)`channel`

.

## Examples

### Get Characteristic Information About TDL Fading Channel

Create an `nrTDLChannel`

System object.

tdl = nrTDLChannel;

To get characteristic information about the channel, call the info function on the object.

channelInfo = info(tdl)

`channelInfo = `*struct with fields:*
ChannelFilterDelay: 7
MaximumChannelDelay: 16
PathDelays: [0 1.1457e-08 1.2075e-08 1.7604e-08 ... ]
AveragePathGains: [-13.4000 0 -2.2000 -4 -6 -8.2000 -9.9000 ... ]
KFactorFirstTap: -Inf
NumTransmitAntennas: 1
NumReceiveAntennas: 2
SpatialCorrelationMatrix: [2x2 double]

## Input Arguments

`channel`

— MIMO channel model

`nrCDLChannel`

| `nrTDLChannel`

| `nrHSTChannel`

MIMO channel model, specified as an `nrCDLChannel`

, `nrTDLChannel`

, or `nrHSTChannel`

System object™.

## Output Arguments

`channelInfo`

— Characteristic information of channel model

structure

Characteristic information of the channel model, `channel`

,
returned as a structure. The fields of the structure depend on the input
`channel`

.

If

`channel`

is an`nrCDLChannel`

System object, the`channelInfo`

structure has these fields.Parameter Field Value Description `PathDelays`

Numeric row vector

Delays of discrete channel paths for each cluster in seconds, returned as a numeric row vector. These values include the effects of

`DelaySpread`

scaling and`KFactorScaling`

(when enabled).`ClusterTypes`

Cell array of character vectors

Type of each cluster in the delay profile, returned as a cell array of character vectors. Cluster types can be

`'LOS'`

,`'SubclusteredNLOS'`

, or`'NLOS'`

.`AveragePathGains`

Numeric row vector

Average path gains of the discrete path or clusters in dB, returned as a numeric row vector. These values include the effect of

`KFactorScaling`

scaling (when enabled).`AnglesAoD`

Numeric row vector

Azimuth of departure angles of the clusters in degrees, returned as a numeric row vector.

`AnglesAoA`

Numeric row vector

Azimuth of arrival angles of the clusters in degrees, returned as a numeric row vector.

`AnglesZoD`

Numeric row vector

Zenith of departure angles of the clusters in degrees, returned as a numeric row vector.

`AnglesZoA`

Numeric row vector

Zenith of arrival angles of the clusters in degrees, returned as a numeric row vector.

`KFactorFirstCluster`

Numeric scalar

K-factor of first cluster of delay profile in dB, returned as a numeric scalar. If the first cluster of the delay profile follows a Laplacian instead of a Rician distribution,

`KFactorFirstCluster`

is`-Inf`

.`NumTransmitAntennas`

Numeric scalar

Number of transmit antenna elements, returned as a numeric scalar.

`NumInputSignals`

Numeric scalar

Number of input signals, returned as a numeric scalar. This value determines the number of columns in the input signal sent through the channel (see

`signalIn`

). The value of`NumInputSignals`

and`NumTransmitAntennas`

structure fields are equal, unless you specify the transmit antenna as a`phased.ReplicatedSubarray`

(Phased Array System Toolbox) or`phased.PartitionedArray`

(Phased Array System Toolbox) phased array object. In case of these two phased antenna arrays,`NumInputSignals`

is equal to the number of antenna subarrays, so`NumInputSignals`

≤`NumTransmitAntennas`

.`NumReceiveAntennas`

Numeric scalar

Number of receive antenna elements, returned as a numeric scalar.

`NumOuputSignals`

Numeric scalar

Number of output signals, returned as a numeric scalar. This value determines the number of columns in the output signal received from the channel (see

`signalOut`

). The value of`NumOutputSignals`

and`NumReceiveAntennas`

structure fields are equal, unless you specify the receive antenna as a`phased.ReplicatedSubarray`

(Phased Array System Toolbox) or`phased.PartitionedArray`

(Phased Array System Toolbox) phased array object. In case of these two phased antenna arrays,`NumOutputSignals`

is equal to the number of subarrays, so`NumOutputSignals`

≤`NumReceiveAntennas`

.`ChannelFilterDelay`

Numeric scalar

Channel filter delay in samples, returned as a numeric scalar.

`MaximumChannelDelay`

Numeric scalar

Maximum channel delay in samples, returned as a numeric scalar. This delay consists of the maximum path delay and the channel filter delay.

**Note**The step of splitting the strongest clusters into subclusters, described in TR 38.901 Section 7.5, requires sorting of the clusters by their average power. If the

`NumStrongestClusters`

property is nonzero (applies only when`DelayProfile`

is set to`'Custom'`

), the fields of the information structure are sorted by average power. That is, the`AveragePathGains`

,`ClusterTypes`

,`PathDelays`

,`AnglesAoD`

,`AnglesAoA`

,`AnglesZoD`

, and`AnglesZoA`

fields are presented in descending order of the average gain.If the

`HasLOSCluster`

property is set to`true`

, the NLOS (Laplacian) part of that cluster and the LOS cluster are not necessarily next to each other. However, the`KFactorFirstCluster`

field still indicates the appropriate K-factor.

If

`channel`

is an`nrTDLChannel`

System object, the`channelInfo`

structure has these fields.Parameter Field Value Description `ChannelFilterDelay`

Numeric scalar

Channel filter delay in samples, returned as a numeric scalar.

`MaximumChannelDelay`

Numeric scalar

Maximum channel delay in samples, returned as a numeric scalar. This delay consists of the maximum path delay and the channel filter delay.

`AveragePathGains`

Numeric row vector

Average path gains of the discrete paths in dB, returned as a numeric row vector. These values include the effect of

`KFactorScaling`

(when enabled).`PathDelays`

Numeric row vector

Delays of discrete channel paths in seconds, returned as a numeric row vector. These values include the effects of

`DelaySpread`

scaling and`KFactorScaling`

(when enabled).`KFactorFirstTap`

Numeric scalar

K-factor of first tap of delay profile in dB, returned as a numeric scalar. If the first tap of the delay profile follows a Rayleigh instead of a Rician distribution,

`KFactorFirstTap`

is`-Inf`

.`NumTransmitAntennas`

Numeric scalar

Number of transmit antennas, returned as a numeric scalar.

`NumReceiveAntennas`

Numeric scalar

Number of receive antennas, returned as a numeric scalar.

`SpacialCorrelationMatrix`

Numeric matrix

Combined correlation matrix or 3-D array, returned as a numeric matrix.

If

`channel`

is an`nrHSTChannel`

System object, the`channelInfo`

structure has these fields.Parameter Field Value Description `PathDelays`

*N*_{S}-by-*N*_{P}numeric matrixAbsolute propagation delays of the discrete channel paths at the input signal sample times in seconds, returned as an

*N*_{S}-by-*N*_{P}numeric matrix, where:*N*_{S}is the number of input samples.*N*_{P}is the number of paths.

If you call the

`info`

function before the first call of the`nrHSTChannel`

System object, this field is returned as`[]`

.`DopplerShifts`

*N*_{S}-by-*N*_{P}numeric matrixDoppler shifts of the discrete paths at the input signal sample times in Hz, returned as an

*N*_{S}-by-*N*_{P}matrix.If you call the

`info`

function before the first call of the`nrHSTChannel`

System object, this field is returned as`[]`

.`PowerLevels`

*N*_{S}-by-*N*_{P}numeric matrixPath gains of the discrete paths at the input signal sample times in dB, returned as an

*N*_{S}-by-*N*_{P}numeric matrix.If you call the

`info`

function before the first call of the`nrHSTChannel`

System object, this field is returned as`[]`

.`CarrierFrequency`

Numeric scalar Carrier frequency (

*f*) in Hz, returned as a numeric scalar equal to*fd*×*c/v*, where:*fd*is the maximum Doppler shift.*v*is the train velocity.*c*is the speed of light.

For static propagation conditions, when

*fd*= 0 and*v*= 0, the carrier frequency is returned as`NaN`

.`NumTransmitAntennas`

Positive integer Number of transmit antennas, returned as a positive integer.

When the

`ChannelFiltering`

property is set to`true`

, this field is equal to the second dimension of the input signal.When the

`ChannelFiltering`

property is set to`false`

, this field is equal to the`NumTransmitAntennas`

property value.

`NumReceiveAntennas`

Positive integer Number of receive antennas, returned as a positive integer.

`ChannelFilterDelay`

Numeric scalar Channel filter delay in samples, returned as numeric scalar. `MaximumChannelDelay`

Numeric scalar

Maximum channel delay in samples, returned as a numeric scalar. This delay consists of the channel filter delay and the maximum propagation delay relative to the minimum propagation delay,

`Dmin`

/*c*:`MaximumChannelDelay`

=`ChannelFilterDelay`

+ (*MaxPropagationDelay*–*MinPropagationDelay*).

**Data Types: **`struct`

## References

[1] 3GPP TR 38.901. “Study on channel model for frequencies
from 0.5 to 100 GHz.” *3rd Generation Partnership Project; Technical
Specification Group Radio Access Network*.

[2] 3GPP TS 38.101-4. “NR; User Equipment (UE) radio
transmission and reception; Part 4: Performance requirements.” *3rd Generation
Partnership Project; Technical Specification Group Radio Access
Network*.

## Extended Capabilities

### C/C++ Code Generation

Generate C and C++ code using MATLAB® Coder™.

## Version History

**Introduced in R2018b**

### R2022b: `channelInfo`

output argument returns maximum channel delay

The `channelInfo`

output argument returns the maximum channel delay.
This delay consists of the maximum path delay and the channel filter delay.

### R2022b: Characteristic information for HST channel models

The function accepts `nrHSTChannel`

System object as input argument.

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