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info

Characteristic information about ray-tracing channel

    Description

    example

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

    Examples

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    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 osm file, see [1].

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

    Create transmitter and receiver sites.

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

    Perform ray tracing to find rays with up to 2 reflections.

    rays = raytrace(tx,rx,"NumReflections",[0 1 2]);

    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: [7×20 double]
              NumSamplesProcessed: 0
    
    

    Appendix

    [1] The osm 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

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

    Output Arguments

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

    Carrier frequency in Hz, returned as a positive scalar.

    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'.

    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'.

    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'.

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

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

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

    Channel filter coefficients, returned as an NP-by-NH 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. NP is the number of paths (specifically, the number of rays as indicated by the length of the PropagationRays property of the rtchan input). NH is the number of impulse response samples (specifically, the number of channel filter taps).

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

    Introduced in R2020b