info

Characteristic information about ray-tracing channel

Since R2020b

Syntax

chanInfo = info(rtchan)

Description

chanInfo = info(rtchan) returns a structure containing characteristic information about the input ray-tracing channel.

Examples

Return Information for Ray-Tracing Channel Between Two Sites in Hong Kong

Perform ray tracing between two sites in Hong Kong, China, build a multipath channel model using the ray-tracing result, and view the ray-tracing channel information.

Create a Site Viewer map display of buildings in Hong Kong. For more information about the OpenStreetMap® file, see [1].

sv = siteviewer(Buildings="hongkong.osm");

Create transmitter and receiver sites.

tx = txsite( ...
    Latitude=22.2789, ...
    Longitude=114.1625, ...
    AntennaAngle=30, ... % azimuth angle
    AntennaHeight=10, ...
    TransmitterFrequency=28e9);
rx = rxsite( ...
    Latitude=22.2799, ...
    Longitude=114.1617, ...
    AntennaAngle=120, ... % azimuth angle
    AntennaHeight=1);

Create a ray tracing model that calculates paths with up to 3 reflections. By default, ray tracing models use the shooting and bouncing rays (SBR) method. Then, perform the ray tracing analysis.

pm = propagationModel("raytracing",MaxNumReflections=3);
rays = raytrace(tx,rx,pm);

Create a channel model by using the transmitter site, receiver site, and calculated rays between the sites. Return information from the ray-tracing channel.

rtchan = comm.RayTracingChannel(rays{1},tx,rx);
info(rtchan)

ans = struct with fields:
             CarrierFrequency: 2.8000e+10
             CoordinateSystem: 'Geographic'
        TransmitArrayLocation: [3×1 double]
         ReceiveArrayLocation: [3×1 double]
          NumTransmitElements: 1
           NumReceiveElements: 1
           ChannelFilterDelay: 4
    ChannelFilterCoefficients: [11×30 double]
          NumSamplesProcessed: 0
                LastFrameTime: 0

Appendix

[1] The OpenStreetMap file is downloaded from https://www.openstreetmap.org, which provides access to crowd-sourced map data all over the world. The data is licensed under the Open Data Commons Open Database License (ODbL), https://opendatacommons.org/licenses/odbl/.

Input Arguments

rtchan — Ray-tracing channel

comm.RayTracingChannel System object™

Ray-tracing channel, specified as a comm.RayTracingChannel System object.

Output Arguments

chanInfo — Ray tracing channel characteristic information

structure

Ray tracing channel characteristic information, returned as a structure containing these fields. The ray tracing channel is specified by the input rtchan.

CarrierFrequency — Carrier frequency

positive scalar

Carrier frequency in Hz, returned as a positive scalar.

CoordinateSystem — Coordinate system

'Cartesian' | 'Geographic'

Coordinate system, returned as 'Cartesian' or 'Geographic'. Any comm.Ray objects, specified by the PropagationRays property of the rtchan input, that have their PathSpecification property set to 'Locations', must have the same CoordinateSystem property setting.

Dependencies

This property applies when at least one comm.Ray object in the PropagationRays property of the rtchan input has PathSpecification set to 'Locations'.

TransmitArrayLocation — Transmit array location

three element column vector

Transmit array location, returned as a three element column vector. Any comm.Ray objects, specified by the PropagationRays property of the rtchan input, that have their PathSpecification property set to 'Locations', must have the same TransmitterLocation property setting.

Dependencies

This property applies when at least one comm.Ray object in the PropagationRays property of the rtchan input has PathSpecification set to 'Locations'.

ReceiveArrayLocation — Receive array location

three element column vector

Receive array location, returned as a three element column vector. Any comm.Ray objects, specified by the PropagationRays property of the rtchan input, that have their PathSpecification property set to 'Locations', must have the same ReceiverLocation property setting.

Dependencies

This property applies when at least one comm.Ray object in the PropagationRays property of the rtchan input has PathSpecification set to 'Locations'.

NumTransmitElements — Number of elements in transmit array

positive integer

Number of elements in the transmit array, returned as a positive integer.

NumReceiveElements — Number of elements in receive array

positive integer

Number of elements in the receive array, returned as a positive integer.

ChannelFilterDelay — Channel filter delay

nonnegative integer

Channel filter delay in samples, returned as a nonnegative integer.

ChannelFilterCoefficients — Channel filter coefficients

N_P-by-N_H matrix

Channel filter coefficients, returned as an N_P-by-N_H matrix. This coefficient matrix is used to convert channel impulse responses to channel filter tap gains for each sample, and then for each pair of transmit and receive antenna elements. N_P is the number of paths (specifically, the number of rays as indicated by the length of the PropagationRays property of the rtchan input). N_H is the number of impulse response samples (specifically, the number of channel filter taps).

NumSamplesProcessed — Number of samples processed by channel object

nonnegative integer

Number of samples processed by the channel object since its last reset, returned as a nonnegative integer.

LastFrameTime — End time of last frame

nonnegative integer

End time of last frame in seconds, returned as a nonnegative integer.

Version History

Introduced in R2020b