Документация

rng('default'); % Reset the random number generator
simParameters = []; % Clear simParameters variable
simParameters.NumFramesSim = 500; % Simulation time in terms of number of 10 ms frames

% UEs are assumed to have sequential radio network temporary identifiers
% (RNTIs) starting from 1 to numUEs
simParameters.NumUEs = 4;

simParameters.UEDistance = [100 250 700 750]; % Distance of UEs from gNB (in meters)

% Mapping between distance from gNB (first column in meters) and maximum
% achievable uplink CQI value (second column). For example, if a UE is 700
% meters away from the gNB, it can achieve a maximum CQI value of 10 as the
% distance falls within [501, 800] meters range, as per the mapping. Set
% distance in increasing order and hence maximum CQI value in decreasing
% order
simParameters.CQIvsDistance = [
                               200  15;
                               500  12;
                               800  10;
                               1000  8;
                              ];

% Set application traffic pattern for UEs. Data is generated on the UEs
% periodically
simParameters.AppPeriodicityUEs = [500 500 400 400]; % Periodicity of application data generated by UEs (in ms)
simParameters.BufferSizesUEs = [180000 150000 120000 100000]; % Size of data (in bytes) generated periodically

% RB count for 5MHz band with 15KHz subcarrier spacing (SCS). The complete
% bandwidth is assumed to be allotted for PUSCH
simParameters.NumPUSCHRBs = 25;
simParameters.SCS = 15;

% Set scheduler run periodicity in terms of number of slots. Value must be
% less than the number of slots in a 10 ms frame
simParameters.SchedulerPeriodicity = 4; 
simParameters.SchedulerStrategy = 'PF'; % Supported scheduling strategies: 'PF', 'RR' and 'BestCQI'

% Moving average parameter within range [0, 1] to calculate average data
% rate for a UE. It is used in PF scheduling strategy. Parameter value
% closer to 1 implies more weightage to the instantaneous data rate.
% Parameter value closer to 0 implies more weightage to the past data rate
% AverageDataRate = ((1 - MovingAvgDataRateParam) * PastDataRate) + (MovingAvgDataRateParam * InstantaneousDataRate)
simParameters.MovingAvgDataRateParam = 0.5;

simParameters.EnableHARQ = true; % Flag to enable or disable HARQ. If disabled, there are no retransmissions
% Maximum RBs allotted to a UE in a slot for a PUSCH transmission (Limit is
% applicable for new PUSCH assignments and not for the retransmissions)
simParameters.RBAllocationLimit = 15;

simParameters.NumHARQ = 16; % Number of HARQ processes in UEs
simParameters.BSRPeriodicity = 5; % In ms

% In accordance with 3GPP TS 38.214, Section 5.1.2.2.1 Table-1.
% Using configuration 1 to determine RBG size from bandwidth size
simParameters.BWPSizeConfig1 = [36 72 144 275]; % Bandwidth size in terms of number of RBs
simParameters.RBGSizeConfig1 = [2 4 8 16]; % Corresponding RBG size in terms of number of RBs

% Configure parameters to update uplink channel conditions at gNB for the
% UEs. It is periodically improved or deteriorated by CQIDelta every
% channelUpdatePeriodicity seconds for all the RBs of a UE. It is randomly
% selected whether the channel conditions deteriorate or improve for a
% particular UE:
% RBCQI = RBCQI +/- CQIDelta
simParameters.ChannelUpdatePeriodicity = 0.5; % In sec
simParameters.CQIDelta = 2;

% The parameter RBVisualization controls the display of these visualizations:
% (i) CQI visualization of RBs
% (ii) RB assignment visualization
simParameters.RBVisualization = true;

% The output metrics plots are updated NumMetricsSteps times within the
% simulation duration
simParameters.NumMetricsSteps = 20;

% MAT files used for post-simulation visualization
simParameters.ParametersLogFile = 'simParameters'; % For logging the simulation parameters
simParameters.SchedulingLogFile = 'schedulingLogs'; % For per slot simulation run logs

hNRULSchedulingValidateConfig(simParameters); % Validate the simulation configuration

simParameters.UERNTIs = 1:simParameters.NumUEs; % RNTI of UEs

% Slot duration for the selected SCS and number of slots in 10 ms frame
simParameters.SlotDuration = 1/(simParameters.SCS/15); % In ms
simParameters.NumSlotsFrame = 10/simParameters.SlotDuration;

simParameters.NumSlotsSim = simParameters.NumFramesSim * simParameters.NumSlotsFrame; % Number of slots in the simulation

% Interval at which metrics visualization updates in terms of number of
% slots. As one slot is the finest time-granularity of the simulation, make
% sure that 'MetricsStepSize' is an integer
simParameters.MetricsStepSize = ceil(simParameters.NumSlotsSim / simParameters.NumMetricsSteps);
if(mod(simParameters.NumSlotsSim, simParameters.NumMetricsSteps))
    % Update the 'NumMetricsSteps' parameter, if 'NumSlotsSim' is not
    % completely divisible by it
    simParameters.NumMetricsSteps = floor(simParameters.NumSlotsSim / simParameters.MetricsStepSize);
end

% Packet periodicities of UEs in terms of number of slots
simParameters.AppPeriodicityUEsSlots = simParameters.AppPeriodicityUEs ./ simParameters.SlotDuration;

% Define uplink channel quality as a N-by-P matrix where N is the number of
% UEs and P is the number of RBs in PUSCH bandwidth. Initial value of CQI
% for each RB, for each of the UEs is given randomly and is limited by the
% maximum achievable CQI value corresponding to distance of UE from gNB
maxUECQIs = zeros(simParameters.NumUEs, 1); % To store the maximum achievable CQI value for UEs
simParameters.ChannelQuality = zeros(simParameters.NumUEs, simParameters.NumPUSCHRBs);

% Find maximum achievable CQI value for UEs based on their distance from
% the gNB
for UEIdx = 1:simParameters.NumUEs
    % Based on UE's distance from gNB, find matching row in CQIvsDistance mapping 
    matchingRowIdx = find(simParameters.CQIvsDistance(:, 1) > simParameters.UEDistance(UEIdx));
    if(isempty(matchingRowIdx))
        maxUECQIs(UEIdx) = simParameters.CQIvsDistance(end, 2);
    else
        maxUECQIs(UEIdx) = simParameters.CQIvsDistance(matchingRowIdx(1), 2);
    end

    % Assign random CQI values for the RBs, limited by the maximum achievable CQI value
    simParameters.ChannelQuality(UEIdx, 1:simParameters.NumPUSCHRBs)  = randi([1 maxUECQIs(UEIdx)], 1, simParameters.NumPUSCHRBs);
end

% Calculate the number of RBs in an RBG. RBG is the smallest unit of
% assignment in frequency domain. Bitmap for frequency domain allocation of
% PUSCH contains one bit per RBG
index = find(simParameters.NumPUSCHRBs <= simParameters.BWPSizeConfig1(:), 1);
simParameters.RBGSize = simParameters.RBGSizeConfig1(index);

% Periodicity of channel update in terms of number of slots
simParameters.ChannelUpdatePeriodicitySlots = floor((simParameters.ChannelUpdatePeriodicity * 1000)/...
                                                    simParameters.SlotDuration);

% Initialize buffers to exchange packets between UEs and gNB
hNRPacketExchangeBuffer(simParameters);

gNB = hNRGNBMAC(simParameters); % Create gNB MAC object
for UEIdx = 1:simParameters.NumUEs
    % Initialize uplink CQI information at gNB for the UEs
    updateUEChannelQualityStatus(gNB, simParameters.UERNTIs(UEIdx), simParameters.ChannelQuality(UEIdx, :));
end

UEs = cell(simParameters.NumUEs, 1); % Array to store UEs' MAC objects
for UEIdx=1:simParameters.NumUEs
    UEs{UEIdx} = hNRUEMAC(simParameters, UEIdx); % Create UE MAC object
end

% To store metrics of UEs for each slot: Throughput bytes transmitted,
% Goodput bytes transmitted, Pending buffer amount bytes. Goodput is
% calculated by excluding the retransmissions from the total transmissions
UESlotMetrics = zeros(simParameters.NumUEs, 3);

channelQuality = zeros(simParameters.NumUEs, simParameters.NumPUSCHRBs); % To store current CQI values on the RBs for different UEs
simLogger = hNRULSchedulingLogger(simParameters); % Create object for visualization and logging

% Run processing loop
for slotNum = 1:simParameters.NumSlotsSim
    if(~mod(slotNum, simParameters.ChannelUpdatePeriodicitySlots)) % Update the uplink channel quality for UEs periodically
        for UEIdx = 1:simParameters.NumUEs
            CQIRBs = getUEChannelQualityStatus(gNB, UEIdx); % Current CQI values
            % Update CQI values for RBs by randomly increasing or
            % decreasing current values randomly by CQIDelta, limited by
            % the minimum and maximum achievable CQI index value. You can
            % customize the updating of CQI values in any desired way here
            updateType = [1 -1]; % Improvement/Deterioration
            channelQualityChange  = updateType(randi(length(updateType)));
            updatedCQIs = min(max(CQIRBs + simParameters.CQIDelta*channelQualityChange, 1), maxUECQIs(UEIdx));
            updateUEChannelQualityStatus(gNB, UEIdx, updatedCQIs);
        end
    end

    % Run the gNB scheduler. Check whether the scheduler is set to run in
    % the slot. If yes, schedule the resources and send the corresponding
    % uplink grants
    resourceAssignments = runScheduler(gNB);
    if(~isempty(resourceAssignments)) % Check if uplink assignments are done
        resourceAssignments = controlTx(gNB, resourceAssignments); % Construct and send uplink grants
    end

    % Run the UE operations: Send MAC packet, Update UE-buffers based on
    % application traffic pattern, Send control information (BSR)
    HARQProcessStatus = zeros(simParameters.NumUEs, simParameters.NumHARQ); % To store last sent HARQ process NDI flag
    for UEIdx = 1:simParameters.NumUEs % For all UEs

        % UE sends MAC packet if it is a Tx slot (as conveyed by gNB in
        % earlier received uplink grants). Output: MAC transmission
        % (throughput) and New MAC transmission (goodput) data respectively
        [UESlotMetrics(UEIdx, 1), UESlotMetrics(UEIdx, 2)] = dataTx(UEs{UEIdx});

        % Add data to UE buffer, based on the application
        % traffic pattern. Return the updated buffer amount
        if~(mod(slotNum-1, simParameters.AppPeriodicityUEsSlots(UEIdx)))
            updateUEBuffer(UEs{UEIdx}, simParameters.BufferSizesUEs(UEIdx));
        end

        UESlotMetrics(UEIdx, 3) = getUEBufferStatus(UEs{UEIdx}); % Read pending buffer (in bytes) on UE

        % UE sends BSR packet, if scheduled to send in this slot
        controlTx(UEs{UEIdx});

        % Read the last received NDI flags for UE HARQ processes (For logging purpose)
        HARQProcessStatus(UEIdx, :) = getLastNDIFlagHarq(UEs{UEIdx});

         % Read the uplink channel quality at gNB for each of the UEs (For logging purpose)
        channelQuality(UEIdx,:) = getUEChannelQualityStatus(gNB, UEIdx);
    end

    % Run the Rx operation at gNB for simultaneous reception of packets
    controlRx(gNB); % Receive BSRs

    % Receive uplink MAC packets from UEs that are scheduled to transmit in
    % this slot. Return the information of Rx success/failure
    rxResultUEs = dataRx(gNB);

    % Run the Rx operation at UEs for simultaneous reception of packets
    for UEIdx = 1:simParameters.NumUEs % For all UEs
        controlRx(UEs{UEIdx}); % Receive uplink grants, if any sent by gNB
    end

    % Update logs based on the current slot run of UEs and gNB. Logs are
    % updated in each slot, RB grid visualizations are updated every frame,
    % and metrics plots are updated every metricsStepSize slots
    logScheduling(simLogger, resourceAssignments, UESlotMetrics, channelQuality, HARQProcessStatus, rxResultUEs);
    if(simParameters.RBVisualization) % If RB Visualization flag is set
        if(~mod(slotNum, simParameters.NumSlotsFrame)) % Last slot of the frame
            frameNum = floor(slotNum/simParameters.NumSlotsFrame)-1;
            plotRBGrids(simLogger, frameNum); % Plot RB assignment grid and CQI grid
        end
    end
    if(~mod(slotNum, simParameters.MetricsStepSize))
        plotMetrics(simLogger); % Plot performance metrics
    end
end

save(simParameters.ParametersLogFile, 'simParameters'); % Save simulation parameters in a MAT file
saveSchedulingLogs(simLogger); % Save scheduling logs in a MAT file