Interactive CDL Channel Model Configuration

Since R2024b

This example shows how to configure a CDL channel model and visualize the channel characteristics and OFDM channel response by using an interactive configuration app.

Introduction

The nrCDLChannel object is a CDL channel model with many properties, which can make programmatic configuration difficult. The effect of these properties over aspects such as the cluster paths, antenna arrays, and the OFDM channel response is not obvious. This example provides a configuration app that enables you to parameterize interactively the CDL channel model. The app provides access to the most common parameters of a CDL channel model. Each parameter on the app corresponds to a property of the nrCDLChannel object. Object properties that are not in the app take their default values. You can modify any property value programmatically after you export your configuration.

Configure CDL Channel

To open the CDL channel configuration app, run the CDLChannelModelConfiguration app file. The app displays the parameters and characteristics of a CDL channel model that corresponds to the default nrCDLChannel object.

>> CDLChannelModelConfiguration

The app enables you to configure the most common parameters of a CDL channel model. When you update the channel parameters, the app automatically updates the figure of the OFDM channel response and the figures that show the geometric and electromagnetic characteristics of the channel at the transmitter and the receiver ends. These figures include the position, orientation, polarization, and directivity radiation pattern of the antenna elements, cluster paths directions, and average path gains. Because all antenna elements are equal, the visualization shows only the radiation pattern of the first antenna element and displays the cluster path directions centered at the first antenna element.

With the app, you can explore the OFDM channel response, which represents the channel magnitude response over all subcarriers and for all 14 OFDM symbols in a 5G slot. The OFDM channel response depends on the number of resource blocks and the subcarrier spacing, which determine the sample rate used to calculate the OFDM response. This sample rate can be obtained from the structure output of nrOFDMInfo. The app displays a warning if the channel sample rate is not equal to the sample rate used to calculate the OFDM channel response.

The OFDM Channel Response figure shows the channel realization between the first transmit and the first receive antennas. The OFDM channel response between other antenna pairs can be different; however, the rate of fading and the response across the subcarriers as shown for the first antenna pair is representative to all antenna pairs.

The app also enables you to create a custom delay profile configuration with a single line of sight (LOS) path by setting Delay profile to Custom: single path. Use this configuration when you want to remove the effect of multipath and use a channel with a flat fading characteristic.

To revert all settings to the default values of an nrCDLChannel object, click New session.

Export Channel Configuration

To export the channel configuration as an nrCDLChannel object to the workspace, click Export to workspace. Alternatively, to generate a script that configures a CDL channel with the parameters you have specified, click Export to script.

Import Channel Configuration

To import and visualize the characteristics of an nrCDLChannel object from the workspace, click Load from workspace. The app opens a dialog box that lists all nrCDLChannel objects in the workspace. Select the object of interest, then click OK.