Evaluate 3GPP Indoor Reference Scenario

eMBB InH Reference Scenario

This example models and simulates an eMBB InH scenario consisting of a single floor within a building.

These are the specifications of the scenario:

The indoor scenario has been modeled to cover a variety of typical indoor environments, including office spaces and shopping centers. The scenario accurately simulates common office layouts, incorporating features such as cubicles, walled private offices, expansive open areas, and corridors. Depending on your simulation requirements, you can configure the channel model as "Open" or "Mixed".

"Open" — The Open Office environment consists of a large open space with minimal obstructions, like an open-plan office area. The signal propagation is relatively uniform, and the user distribution is typically even. This scenario is used to model high-capacity areas, where you expect many users to access the network simultaneously.

"Mixed" — The Mixed Office environment is more complex, consisting of a combination of open areas and closed offices with walls and partitions. The user distribution is more varied, and the signal experiences more multipath fading and shadowing effects. Use this scenario to model typical office environments, with a mix of open spaces and enclosed rooms.

Simulation Assumptions

In this example, these assumptions apply:

Configure and Simulate Scenario

Check if the Communications Toolbox™ Wireless Network Simulation Library support package is installed. If the support package is not installed, MATLAB® returns an error with a link to download and install the support package.

wirelessnetworkSupportPackageCheck

Reset the seed value for the random number generator. The seed value controls the pattern of random number generation. To improve the accuracy of your simulation results after running the simulation, you can change the seed value, run the simulation again, and average the results over multiple simulations.

rng("default");

Specify the simulation time in terms of number of 10 ms frames.

numFrameSimulation = 1;

Initialize the wireless network simulator.

networkSimulator = wirelessNetworkSimulator.init;

Configure gNBs and UEs

Specify the frequency and bandwidth at which the carrier served by the gNB operates. The subcarrier spacing in the carrier frequency is 15 kHz.

carrierFreq = 4e9;  % In Hz
channelBW = 10e6; % In Hz

Specify the number of gNBs in the vertical and horizontal directions.

numVerticalGNB = 2;
numHorizontalGNB = 6; 

Specify the number of transmit and receive antennas for the gNBs.

gNBNumTransmitAntennas = 32;
gNBNumReceiveAntennas = 4;

Specify the noise figure and transmit power of the gNB.

gNBNoiseFigure = 5; % In dB
gNBTxPower = 21;    % In dBm

Specify the number of UEs connected to each gNB. According to the 3GPP TR 38.913, a gNB is typically assigned 10 UEs. However, To keep simulation runtime in check, this example uses a default value of 2 UEs per gNB.

numUEsPerGNB = 2;

Specify the number of transmit and receive antennas for the UEs.

ueNumTransmitAntennas = 4;
ueNumReceiveAntennas = 4;

Specify the noise figure and transmit power of the UE.

ueNoiseFigure = 7; % In dB
ueTxPower = 23;    % In dBm

Create gNBs and UEs in each cell of the InH scenario.

scenario = h3GPPReferenceScenarios(Scenario="InH",NumUEs=numUEsPerGNB, ...
     NumGNBsHorizontal=numHorizontalGNB,NumGNBsVertical=numVerticalGNB, ...
     Visualization=false);
gNBCoordinates = scenario.GNBPositions;
ueCoordinates = scenario.UEPositions;

Create gNBs and Configure Scheduler

Create the gNBs from the specified configuration. Each gNB operates one NR cell.

gNBs = nrGNB(Position=gNBCoordinates,NoiseFigure=gNBNoiseFigure, ...
     CarrierFrequency=carrierFreq,ChannelBandwidth=channelBW, ...
     NumReceiveAntennas=gNBNumReceiveAntennas,NumTransmitAntennas=gNBNumTransmitAntennas, ...
     TransmitPower=gNBTxPower);

Compute the total number of gNBs.

numGNBs = size(gNBs,2);

Configure the LA parameters. The parameters specify a 10 percent target BLER for the UL and DL configurations.

laConfigDL = struct("StepUp",0.27,"StepDown",0.03,"InitialOffset",1);
laConfigUL = struct("StepUp",0.27,"StepDown",0.03,"InitialOffset",1);

Configure the scheduler by specifying the gNBs, maximum number of users per transmission time interval (TTI), and LA configuration.

configureScheduler(gNBs,MaxNumUsersPerTTI=10,...
    LinkAdaptationConfigDL=laConfigDL,LinkAdaptationConfigUL=laConfigUL)

Configure the UL power control parameters.

for gNBIndex = 1:numGNBs
    configureULPowerControl(gNBs(gNBIndex),Alpha=0.6)
end

Create UEs and Configure Application Traffic

Create the UEs from the specified configuration.

UEs = nrUE(Position=ueCoordinates,TransmitPower=ueTxPower, ...
     NumTransmitAntennas=ueNumTransmitAntennas, ...
     NumReceiveAntennas=ueNumReceiveAntennas,NoiseFigure=ueNoiseFigure);

Connect the UEs to the gNB. Configure and add UL and DL full buffer traffic between each gNB and its connected UEs.

startUEIndex = 1;
ueListInGNB = cell(1,numGNBs);
for gNBIndex = 1:numGNBs
    connectUE(gNBs(gNBIndex),UEs(startUEIndex:startUEIndex+numUEsPerGNB-1), ...
        CSIReportPeriodicity=160,FullBufferTraffic="on")
    ueListInGNB{gNBIndex} = UEs(startUEIndex:startUEIndex+numUEsPerGNB-1);
    startUEIndex = startUEIndex + numUEsPerGNB;
end

Add the gNBs and UEs to the wireless network simulator.

addNodes(networkSimulator,gNBs);
addNodes(networkSimulator,UEs);

Configure Channel Model

Create a system-level channel model for the scenario.

channel = h38901Channel(Scenario="InH");

Specify the channel type as "Open" or "Mixed".

channel.OfficeType = "Mixed";
chcfg.Site = 1:numGNBs;

Specify the transmit antenna array orientation.

chcfg.TransmitArrayOrientation = [0 90 0]';

Add the channel to the wireless network simulator.

addChannelModel(networkSimulator,@channel.channelFunction);
% Connect the simulator and channel model
connectNodes(channel,networkSimulator,chcfg,InterfererHasSmallScale=true);

Run Simulation and Visualize Metrics

Specify the number of metric steps.

numMetricsSteps = 10*numFrameSimulation;

Specify the cell ID for the desired gNB to access its corresponding visualizations and metrics.

cellOfInterest = 1;

To visualize PHY and MAC metrics, create and configure the helperNRMetricsVisualizer object.

metricsVisualizer = cell(numGNBs,1);
for cellIdx = 1:numGNBs
    if cellIdx == cellOfInterest
        metricsVisualizer{cellIdx} = helperNRMetricsVisualizer(gNBs(cellIdx),ueListInGNB{cellIdx}, ...
            NumMetricsSteps=numMetricsSteps,PlotSchedulerMetrics=false,PlotPhyMetrics=false, ...
            CellOfInterest=cellIdx,PlotCDFMetrics=true);
    else
        metricsVisualizer{cellIdx} = helperNRMetricsVisualizer(gNBs(cellIdx),ueListInGNB{cellIdx}, ...
            NumMetricsSteps=numMetricsSteps,PlotSchedulerMetrics=false,PlotPhyMetrics=false, ...
            CellOfInterest=cellIdx,PlotCDFMetrics=false);
    end
end

Compute the simulation time from the specified numFrameSimulation frames.

simTime = numFrameSimulation*1e-2;

Run the simulation.

run(networkSimulator,simTime)

Results

The results display the system KPIs, which include cell throughput, spectral efficiency, and empirical cumulative distribution function (ECDF) plots for both cell throughput and average BLER. Use the ECDF plots to determine the proportion of users whose throughput and BLER is less than or equal to a specific value indicated on the x-axis.

fprintf("\n\nMetrics for site %d:\n\n",cellOfInterest)

Metrics for site 1:

displayPerformanceIndicators(metricsVisualizer{cellOfInterest})

Peak UL throughput: 258.80 Mbps. Achieved cell UL throughput: 8.36 Mbps
Achieved UL throughput for each UE: [2.96         5.4]
Peak UL spectral efficiency: 25.88 bits/s/Hz. Achieved UL spectral efficiency for cell: 0.84 bits/s/Hz 
Block error rate for each UE in the UL direction: [0.375       0.375]

Peak DL throughput: 258.80 Mbps. Achieved cell DL throughput: 7.94 Mbps
Achieved DL throughput for each UE: [0        7.94]
Peak DL spectral efficiency: 25.88 bits/s/Hz. Achieved DL spectral efficiency for cell: 0.79 bits/s/Hz
Block error rate for each UE in the DL direction: [1       0.444]

Display the system KPI plots for the scenario.

scenario.displayScenarioPlots(metricsVisualizer,numGNBs,numFrameSimulation)

Further Exploration

You can use this example to further explore these capabilities.

Compare the Wideband SINR in eMBB InH Scenario with 3GPP Reference Scenario

The simulation scenario in the 3GPP Document RP-180524 distributes UEs randomly across a rectangular area around each gNB, with UE to gNB associations determined by path loss calculations. The simulation runs a full buffer traffic model, adopts resource allocation type 1 (RAT-1), and uses a round-robin scheduling algorithm. To achieve a target BLER of 10 percent in the UL and DL, respectively, the simulation configures the LA parameters, LinkAdaptationConfigUL and LinkAdaptationConfigDL. The configuration sets the UL power control alpha parameter to 0.6. For accurate measurement of Wideband SINR, the maximum number of users per TTI value is set to 1. For more information about the simulation scenario, see CompareInHScenarioWith3GPPReferenceScenario.m script.

The assumptions and limitations of these simulations are:

The results also contain a comparison of the wideband SINR in the InH scenario with the 3GPP reference models, following the assumptions and specficiations in the section 4.1 in the 3GPP document RP-180524.

Analyze the Impact of Link Adaptation, Channel, and Antenna Configuration on KPIs

Supporting Functions

The example uses these helper objects and functions: