rng('default'); % Reset the random number generator
simParameters = []; % Clear the simParameters variable

simParameters.NumFramesSim = 30; % Simulation time in terms of number of 10 ms frames
% Number of UEs in the simulation. UEs are assumed to have sequential radio
% network temporary identifiers (RNTIs) from 1 to NumUEs. If you change the
% number of UEs, ensure that the following simulation parameters are array
% of length equal to NumUEs: simParameters.UEDistance,
% simParameters.ULPacketPeriodicityUEs, simParameters.ULPacketSizesUEs,
% simParameters.DLPacketPeriodicityUEs, simParameters.DLPacketSizesUEs
simParameters.NumUEs = 4;
simParameters.UEDistance = [100; 400; 1500; 1000];

% Set the channel bandwidth to 5 MHz and subcarrier spacing (SCS) to 15
% kHz as defined in 3GPP TS 38.104 Section 5.3.2
% RB count for 5 MHz band with 15 kHz SCS. The complete
% bandwidth is assumed to be allotted for PUSCH/PDSCH
simParameters.NumRBs = 25;
simParameters.SCS = 15; % kHz
simParameters.DLCarrierFreq = 2.635e9; % Hz
simParameters.ULCarrierFreq = 2.515e9; % Hz
% The UL and DL carriers are assumed to have symmetric channel
% bandwidth
simParameters.DLBandwidth = 5e6; % Hz
simParameters.ULBandwidth = 5e6; % Hz

simParameters.UETxPower = 23; % Tx power for all the UEs in dBm
simParameters.GNBTxPower = 29; % Tx power for gNB in dBm
simParameters.RxGain = 11; % Receiver antenna gain at gNB

% SINR to CQI mapping table for 0.1 BLER
simParameters.SINR90pc = [-5.46 -0.46 4.54 9.05 11.54 14.04 15.54 18.04 ...
    20.04 22.43 24.93 25.43 27.43 30.43 33.43];

simParameters.SchedulerStrategy = 'PF'; % Supported scheduling strategies: 'PF', 'RR', and 'BestCQI'
% Maximum limit on the RBs allotted for PUSCH and PDSCH
% Transmission limit is applicable for new PUSCH and PDSCH assignments and
% not for the retransmissions
simParameters.RBAllocationLimitUL = 15; % For PUSCH
simParameters.RBAllocationLimitDL = 15; % For PDSCH

% Logging and Visualization Configuration
% The parameters CQIVisualization and RBVisualization control the display
% of these visualizations: (i) CQI visualization of RBs (ii) RB assignment
% visualization. By default, the 'RBVisualization' plot is disabled. You
% can enable it by setting to 'true'
simParameters.CQIVisualization = true;
simParameters.RBVisualization = false;
% The output metrics plots are updated periodically NumMetricsSteps times within the
% simulation duration
simParameters.NumMetricsSteps = 20;
% MAT-files to write the logs into. They are used for post simulation analysis and visualization
simParameters.ParametersLogFile = 'simParameters'; % For logging the simulation parameters
simParameters.SimulationLogFile = 'simulationLogs'; % For logging the simulation logs

% Enable packet capture (PCAP)
simParameters.PCAPLogging = false; % Set the value to true to enable packet capture for UEofInterest
simParameters.UEofInterest = 1; % Log the packets of UE with this RNTI

% Set the periodic UL and DL application traffic pattern for UEs
simParameters.ULPacketPeriodicityUEs = [10; 20; 20; 30]; % Periodicity (in ms) at which the UL packets are generated by UEs
simParameters.ULPacketSizesUEs = [8000; 8000; 7500; 8500]; % Size of the UL packets (in bytes) generated by UEs
simParameters.DLPacketPeriodicityUEs = [10; 20; 30; 30]; % Periodicity (in ms) at which the DL packets are generated for UEs at gNB
simParameters.DLPacketSizesUEs = [10000; 9000; 7500; 7500]; % Size of the DL packets generated (in bytes) for UEs at gNB

% Validate the simulation configuration
hNRCellPerformanceWithPhysicalLayerValidateConfig(simParameters);

simParameters.DuplexMode = 0; % FDD
simParameters.NCellID = 1; % Physical cell ID
simParameters.Position = [0 0 0]; % Position of gNB in (x,y,z) coordinates
simParameters.CSIRSRowNumber = 2; % Possible row numbers for single transmit antenna case are 1 and 2
simParameters.SubbandSize = 8; % Size of sub-band for CQI reporting in terms of number of RBs
simParameters.ChannelModelType = 'CDL'; % To model CDL propagation channel
% gNB ensures that PUSCH assignment is received at UEs PUSCHPrepTime ahead
% of the transmission time
simParameters.PUSCHPrepTime = 200; % In microseconds
% Slot duration for the selected SCS and number of slots in a 10 ms frame
slotDuration = 1/(simParameters.SCS/15); % In ms
numSlotsFrame = 10/slotDuration; % Number of slots in a 10 ms frame
numSlotsSim = simParameters.NumFramesSim * 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(numSlotsSim / simParameters.NumMetricsSteps);
if mod(numSlotsSim, simParameters.NumMetricsSteps) ~= 0
    % Update the NumMetricsSteps parameter if NumSlotsSim is not
    % completely divisible by it
    simParameters.NumMetricsSteps = floor(numSlotsSim / simParameters.MetricsStepSize);
end

% DL and UL packet periodicities for UEs in terms of number of slots
appPeriodicityUEsSlotsUL = simParameters.ULPacketPeriodicityUEs ./ slotDuration;
appPeriodicityUEsSlotsDL = simParameters.DLPacketPeriodicityUEs ./ slotDuration;

simParameters.NumLogicalChannels = 1; % Only 1 logical channel is assumed in each UE in this example

% Mapping between logical channel and logical channel group ID
simParameters.LCHConfig.LCGID = ones(simParameters.NumUEs, simParameters.NumLogicalChannels);
% Priority of each logical channel
simParameters.LCHConfig.Priority = ones(simParameters.NumUEs, simParameters.NumLogicalChannels);
% Prioritized bitrate (in kilo bytes per second) of each logical channel
simParameters.LCHConfig.PBR = 8*ones(simParameters.NumUEs, simParameters.NumLogicalChannels);
% Bucket size duration (BSD) of each logical channel (in ms). However, the priority,
% PBR and BSD for logical channel is not relevant with single logical
% channel assumed in this example
simParameters.LCHConfig.BSD = 10*ones(simParameters.NumUEs, simParameters.NumLogicalChannels);
% Logical channel id (logical channel ID of data radio bearers starts from 4) 
simParameters.LCHConfig.LCID = ones(simParameters.NumUEs, simParameters.NumLogicalChannels) .* (4:4+simParameters.NumLogicalChannels-1);

% RLC entity direction. Value 0 represents DL only, 1
% represents UL only and 2 represents both UL and DL
% direction. Setting entity direction to have both UL and DL
simParameters.RLCConfig.EntityDir = 2*ones(simParameters.NumUEs, simParameters.NumLogicalChannels);

% Maximum RLC SDU length (in bytes) as per 3GPP TS 38.323
simParameters.maxRLCSDULength = 9000;

gNB = hNRGNB(simParameters); % Create gNB node
% Create scheduler
switch(simParameters.SchedulerStrategy)
    case 'RR' % Round robin scheduler
        scheduler = hNRSchedulerRoundRobin(simParameters);
    case 'PF' % Proportional fair scheduler
        scheduler = hNRSchedulerProportionalFair(simParameters);
    case 'BestCQI' % Best CQI scheduler
        scheduler = hNRSchedulerBestCQI(simParameters);
end
addScheduler(gNB, scheduler); % Add scheduler to gNB

gNB.PhyEntity = hNRGNBPhy(simParameters); % Create the PHY layer instance
configurePhy(gNB, simParameters); % Configure the PHY layer
setPhyInterface(gNB); % Set the interface to PHY layer

% Create the set of UE nodes
UEs = cell(simParameters.NumUEs, 1);
for ueIdx=1:simParameters.NumUEs
    simParameters.Position = [simParameters.UEDistance(ueIdx) 0 0]; % Position of UE
    UEs{ueIdx} = hNRUE(simParameters, ueIdx);
    UEs{ueIdx}.PhyEntity = hNRUEPhy(simParameters, ueIdx); % Create the PHY layer instance
    configurePhy(UEs{ueIdx}, simParameters); % Configure the PHY layer
    setPhyInterface(UEs{ueIdx}); % Set up the interface to PHY layer
    
    % Setup the logical channels and add application traffic
    for lcIdx = 1:simParameters.NumLogicalChannels
        % Create RLC channel configuration structure
        rlcChannelConfigStruct.EntityType = simParameters.RLCConfig.EntityDir(ueIdx, lcIdx);
        rlcChannelConfigStruct.LogicalChannelID = simParameters.LCHConfig.LCID(ueIdx, lcIdx);
        rlcChannelConfigStruct.LCGID = simParameters.LCHConfig.LCGID(ueIdx, lcIdx);
        rlcChannelConfigStruct.Priority = simParameters.LCHConfig.Priority(ueIdx, lcIdx);
        rlcChannelConfigStruct.PBR = simParameters.LCHConfig.PBR(ueIdx, lcIdx);
        rlcChannelConfigStruct.BSD = simParameters.LCHConfig.BSD(ueIdx, lcIdx);
        % Setup logical channel at gNB for the UE
        configureLogicalChannel(gNB, ueIdx, rlcChannelConfigStruct);
        % Setup logical channel at UE
        configureLogicalChannel(UEs{ueIdx}, ueIdx, rlcChannelConfigStruct);
        
        % Add data traffic pattern generators to gNB and UE nodes
        ulPacketSize = simParameters.ULPacketSizesUEs(ueIdx);
        % Calculate the data rate (in kbps) of On-Off traffic pattern using
        % packet size (in bytes) and packet interval (in ms)
        ulDataRate = ceil(1000/simParameters.ULPacketPeriodicityUEs(ueIdx)) * ulPacketSize * 8e-3;
        % Limit the size of the generated application packet to the maximum RLC
        % SDU size. The maximum supported RLC SDU size is 9000 bytes
        if ulPacketSize > simParameters.maxRLCSDULength
            ulPacketSize = simParameters.maxRLCSDULength;
        end
        
        % Create an object for On-Off network traffic pattern and add it to the
        % specified UE. This object generates the uplink data traffic on the UE
        ulApp = networkTrafficOnOff('PacketSize', ulPacketSize, 'GeneratePacket', true, ...
            'OnTime', simParameters.NumFramesSim/100, 'OffTime', 0, 'DataRate', ulDataRate);
        UEs{ueIdx}.addApplication(ueIdx, simParameters.LCHConfig.LCID(ueIdx, lcIdx), ulApp);
        
        dlPacketSize = simParameters.DLPacketSizesUEs(ueIdx);
        dlDataRate = ceil(1000/simParameters.DLPacketPeriodicityUEs(ueIdx)) * dlPacketSize *8e-3;
        if dlPacketSize > simParameters.maxRLCSDULength
            dlPacketSize = simParameters.maxRLCSDULength;
        end
        
        % Create an object for On-Off network traffic pattern for the specified
        % UE and add it to the gNB. This object generates the downlink data
        % traffic on the gNB for the UE
        dlApp = networkTrafficOnOff('PacketSize', dlPacketSize, 'GeneratePacket', true, ...
            'OnTime', simParameters.NumFramesSim/100, 'OffTime', 0, 'DataRate', dlDataRate);
        gNB.addApplication(ueIdx, simParameters.LCHConfig.LCID(ueIdx, lcIdx), dlApp);
    end
end
% Setup the UL and DL packet distribution mechanism
simParameters.MaxReceivers = simParameters.NumUEs;
% Create DL packet distribution object
dlPacketDistributionObj = hNRPacketDistribution(simParameters, 0); % 0 for DL
% Create UL packet distribution object
ulPacketDistributionObj = hNRPacketDistribution(simParameters, 1); % 1 for UL
hNRSetUpPacketDistribution(simParameters, gNB, UEs, dlPacketDistributionObj, ulPacketDistributionObj);

% Enable PCAP logging
if simParameters.PCAPLogging
    % To generate unique file name for every simulation run
    ueCapturefileName = strcat('CellID-', num2str(simParameters.NCellID), '_ue-',num2str(simParameters.UEofInterest), '_', num2str(now));
    enablePacketLogging(UEs{simParameters.UEofInterest}.PhyEntity, ueCapturefileName);
    
    % Uncomment the below code to enable packet capture at gNB
    % gnbCapturefileName = strcat('CellID-', num2str(simParameters.NCellID), '_gNB-', num2str(now));
    % enablePacketLogging(gNB.PhyEntity, gnbCapturefileName);
end

% To store these UE metrics for each slot: throughput bytes
% transmitted, goodput bytes transmitted, and pending buffer amount bytes.
% The number of goodput bytes is calculated by excluding the
% retransmissions from the total transmissions
UESlotMetricsUL = zeros(simParameters.NumUEs, 3);
UESlotMetricsDL = zeros(simParameters.NumUEs, 3);

% To store current UL and DL CQI values on the RBs for the UEs
uplinkChannelQuality = zeros(simParameters.NumUEs, simParameters.NumRBs);
downlinkChannelQuality = zeros(simParameters.NumUEs, simParameters.NumRBs);

% To store last received new data indicator (NDI) values for UL and DL HARQ processes
HARQProcessStatusUL = zeros(simParameters.NumUEs, 16);
HARQProcessStatusDL = zeros(simParameters.NumUEs, 16);

% Create an object for MAC (UL & DL) scheduling information visualization and logging
simSchedulingLogger = hNRSchedulingLogger(simParameters);
% Create an object for PHY metrics logging and visualization
simPhyLogger = hNRPhyLogger(simParameters);
symbolNum = 0;

% Run processing loop
for slotNum = 1:numSlotsSim
    
    % Run MAC and PHY of gNB
    run(gNB.MACEntity);
    run(gNB.PhyEntity);
    
    % Run MAC and PHY of UEs
    for ueIdx = 1:simParameters.NumUEs
        % Read the last received NDI flags for HARQ processes for
        % logging (Reading it before it gets overwritten by run function of MAC)
        HARQProcessStatusUL(ueIdx, :) = getLastNDIFlagHarq(UEs{ueIdx}.MACEntity, 1); % 1 for UL
        HARQProcessStatusDL(ueIdx, :) = getLastNDIFlagHarq(UEs{ueIdx}.MACEntity, 0); % 0 for DL
        run(UEs{ueIdx}.MACEntity);
        run(UEs{ueIdx}.PhyEntity);
    end
    
    % MAC logging
    % Read UL and DL assignments done by gNB MAC scheduler
    % at current time. Resource assignments returned by a scheduler (either
    % UL or DL) is empty, if either scheduler was not scheduled to run at
    % the current time or no resources got scheduled
    [resourceAssignmentsUL, resourceAssignmentsDL] = getCurrentSchedulingAssignments(gNB.MACEntity);
    % Read throughput and goodput bytes sent for each UE
    [UESlotMetricsDL(:, 1), UESlotMetricsDL(:, 2)] = getTTIBytes(gNB);
    UESlotMetricsDL(:, 3) = getBufferStatus(gNB); % Read pending buffer (in bytes) on gNB, for all the UEs
    for ueIdx = 1:simParameters.NumUEs
        % Read the UL channel quality at gNB for each of the UEs for logging
        uplinkChannelQuality(ueIdx,:) = getChannelQuality(gNB, 1, ueIdx); % 1 for UL
        % Read the DL channel quality at gNB for each of the UEs for logging
        downlinkChannelQuality(ueIdx,:) = getChannelQuality(gNB, 0, ueIdx); % 0 for DL
        % Read throughput and goodput bytes transmitted for this UE in the
        % current TTI for logging
        [UESlotMetricsUL(ueIdx, 1), UESlotMetricsUL(ueIdx, 2)] = getTTIBytes(UEs{ueIdx});
        UESlotMetricsUL(ueIdx, 3) = getBufferStatus(UEs{ueIdx}); % Read pending buffer (in bytes) on UE
    end
    % Log the scheduling logs
    logScheduling(simSchedulingLogger, symbolNum + 1, resourceAssignmentsUL, UESlotMetricsUL, uplinkChannelQuality, HARQProcessStatusUL, 1);
    logScheduling(simSchedulingLogger, symbolNum + 1, resourceAssignmentsDL, UESlotMetricsDL, downlinkChannelQuality, HARQProcessStatusDL, 0);
    
    % PHY logging
    % Read the DL BLER for each UE
    ueBLERStats = zeros(simParameters.NumUEs, 2);
    for ueIdx = 1:simParameters.NumUEs
        ueBLERStats(ueIdx, :) = getDLBLER(UEs{ueIdx}.PhyEntity);
    end
    % Read the UL BLER for each UE
    gNBBLERStats = getULBLER(gNB.PhyEntity);
    % Log the UL and DL error logs
    logBLERStats(simPhyLogger, ueBLERStats, gNBBLERStats);
    
    % Visualization
    % RB assignment visualization (if enabled)
    if simParameters.RBVisualization
        if mod(slotNum, numSlotsFrame) == 0
            plotRBGrids(simSchedulingLogger);
        end
    end
    % CQI grid visualization (if enabled)
    if simParameters.CQIVisualization
        if mod(slotNum, numSlotsFrame) == 0
            plotCQIRBGrids(simSchedulingLogger);
        end
    end
    % If the update periodicity is reached, plot scheduler metrics and PHY metrics visualization
    % at slot boundary
    if mod(slotNum, simParameters.MetricsStepSize) == 0
        plotMetrics(simSchedulingLogger);
        plotMetrics(simPhyLogger);
    end
    
    % Advance timer ticks for gNB and UEs by 14 symbols
    advanceTimer(gNB, 14);
    for ueIdx = 1:simParameters.NumUEs
        advanceTimer(UEs{ueIdx}, 14);
    end
    
    % Symbol number in the simulation
    symbolNum = symbolNum + 14;
end

simulationLogs = cell(1,1);
logInfo = struct('DLTimeStepLogs',[], 'ULTimeStepLogs',[], 'SchedulingAssignmentLogs',[] ,'BLERLogs',[]);
[dlStats, ulStats] = simSchedulingLogger.getPerformanceIndicators(simParameters.ULBandwidth, simParameters.DLBandwidth);
logInfo.BLERLogs = getBLERLogs(simPhyLogger); % Block Error rate logs
fprintf('Peak UL throughput: %0.2f Mbps. Achieved average UL Throughput: %0.2f Mbps', ulStats(1, 1), ulStats(2, 1));

fprintf('\nPeak DL throughput: %0.2f Mbps. Achieved average DL Throughput: %0.2f Mbps', dlStats(1, 1), dlStats(2, 1));

fprintf('\nPeak UL spectral efficiency: %0.2f bits/s/Hz. Achieved average UL spectral efficiency: %0.2f bits/s/Hz ', ulStats(3, 1), ulStats(4, 1));

fprintf('\nPeak DL spectral efficiency: %0.2f bits/s/Hz. Achieved average DL spectral efficiency: %0.2f bits/s/Hz', dlStats(3, 1), dlStats(4, 1));

fprintf('\nBlock error rate for each UE in the uplink direction: %0.2f %0.2f %0.2f %0.2f', logInfo.BLERLogs{end, 5});

fprintf('\nBlock error rate for each UE in the downlink direction: %0.2f %0.2f %0.2f %0.2f \n', logInfo.BLERLogs{end, 3});

% Read the logs and save them in MAT-files
[logInfo.DLTimeStepLogs, logInfo.ULTimeStepLogs] = getSchedulingLogs(simSchedulingLogger);
logInfo.SchedulingAssignmentLogs = getGrantLogs(simSchedulingLogger); % Scheduling assignments log
simulationLogs{1} = logInfo;
save(simParameters.ParametersLogFile, 'simParameters'); % Save simulation parameters in a MAT-file
save(simParameters.SimulationLogFile, 'simulationLogs'); % Save simulation logs in a MAT-file