Error in running NOMA scenario

Dear Sir;
when I run my scenario from the main.m using MATLAB2022a , I got the following error massage

The sampling rate was set to 7.560000 MHz.
Sampling rate does not match the predefined delays of the channel model!
Delay taps are changed according to (top = desired value; bottom = chosen value):
1.0e-06 *

     0    0.1100    0.1900    0.4100
     0    0.1323    0.1323    0.3968

------- Started -------
Warning: The temporary variable ‘signalLength’ will be cleared at the beginning of each iteration of the
parfor-loop. If ‘signalLength’ is used before it is set, a runtime error will occur. For more
information, see Parallel for Loops in MATLAB, “Uninitialized Temporaries”.

In main (line 48)
Error using MIMO.MimoProcessing/setLayerMapping
Unable to perform assignment with 0 elements on the right-hand side.

Error in Elements.Link/updateLink (line 258)
obj.MIMO.setLayerMapping(obj.Direction);

Error in main (line 48)
parfor iSweep = 1:length(simParams.simulation.sweepValue) % this may be ‘for’ or ‘parfor’

please help me to find the problem

my scenario :

%% Topology
% Specifiy all the nodes in ascending order with starting
% index of 1 (BS0 or UE0 is not allowed).
scStr.topology.nodes = [‘BS1,UE1,UE2,UE3,UE4’];

% Primary (desired) links
scStr.topology.primaryLinks = [‘BS1:UE1,’…
‘BS1:UE2,’…
‘BS1:UE3,’…
‘BS1:UE4’
];

% Links for Joint Tranmission and Detection (future work)
scStr.topology.jointTxRxLinks = [‘’];

% Interference Links
scStr.topology.interferenceGeneration = ‘Automatic’;

scStr.topology.attenuation = 300; % in dB, set a very high attenuation level to virtually decouple the two BS
scStr.topology.interferingLinks = [];

%% General Simulation Parameters
% set link types to simulate
scStr.simulation.simulateDownlink = true; % downlink
scStr.simulation.simulateUplink = false; % uplink
scStr.simulation.simulateD2D = false; % device to device links

scStr.simulation.frameStructure = ‘FDD’; % ‘TDD’ or ‘FDD’

% Plot options
scStr.simulation.plotResultsFor = [1];
scStr.simulation.plotOverSNR = false;
scStr.simulation.plotPAPR = false;

scStr.simulation.saveData = false;

% Define a sweep parameter
scStr.simulation.sweepParam = {‘simulation.txPowerBaseStation’}; % Define the parameter to sweep over. This can be almost any simulation parameter.
% Most likely it will be the pathloss to obtain results over SNR.

scStr.simulation.sweepValue = linspace(-35, 40, 12); % Define parameter values to sweep over, in dB. A good starting point for the pathloss is 150 to 110
scStr.simulation.applySweepingTo = [1];

% Number of simulation frames
scStr.simulation.nFrames = 100; % Number of frames to simulate per sweep value, adjust to obtain sufficiently small confidence intervals.

%% Physical Transmission Parameters
scStr.simulation.centerFrequency = 2.5e9; % center frequency

scStr.simulation.txPowerBaseStation = [30]; % per BS; base station total transmit power in dBm
scStr.simulation.txPowerUser = [30]; % per UE; user total transmit power in dBm

scStr.simulation.codebook = ‘5G’; % LTE or 5G
scStr.simulation.nAntennasBaseStation = [2]; % per BS; number of antennas at the base station
scStr.simulation.antennaConfiguration = {[1,1],[1,1]}; % per BS: if the 5G codebook is selected, each vector represents the number of horizontal and vertical antennas[N1,N2]
% Supported configurations (N1,N2):
% 4 Ports: (2,1)
% 8 Ports: (2,2), (4,1)
% 12 Ports: (3,2),(6,1)
% 16 Ports: (4,2), (8,1)
% 24 Ports: (4,3), (6,2),(12,1)
% 32 Ports: (4,4), (8,2), (16,1)
scStr.simulation.nAntennasUser = [2]; % per UE; number of antennas at the user
scStr.simulation.userVelocity = [0]; % per UE; velocity in m/s

% Links to UE1 and UE3 have pathloss of 80, UE2 and UE4 of 90, and UE5 and UE6 of 110 and 115, respectively (cell edge).
scStr.simulation.pathloss = [80,90,110,115]; % per Link, channel pathloss in dB, this is most likely swept over

% Nonlinearity model
scStr.simulation.nonlinearity = false; % Apply Rapp’s PA nonlinear model: Rapp, C. “Effects of HPA-nonlinearity on a 4-DPSK/OFDM-signal for a digital sound broadcasting signal.”
scStr.simulation.amplifierOBO = [1]; % Amplifier output back-off, per Link, in dB
scStr.simulation.smoothnessFactor = [3]; % Smoothness factor for the Rapp model, per Link, >=0

%% Channel Parameters
scStr.channel.spatialChannelModel = false; % for a 3D channel, this parameter has to be set to ture
scStr.channel.dopplerModel = ‘Discrete-Jakes’;
scStr.channel.timeSubsamplingFactor = 10;
scStr.channel.correlatedFrames = false;
scStr.channel.spatialCorrelation = ‘none’;
scStr.channel.nPaths = 50;
scStr.channel.powerDelayProfile = ‘PedestrianA’;
scStr.channel.K = 0;
scStr.channel.delta = 1;

%% Channel Estimation and Equalization Parameters
scStr.simulation.channelEstimationMethod = ‘Approximate-Perfect’;
scStr.simulation.noisePowerEstimation = false;
scStr.simulation.pilotPatternDownlink = ‘Diamond’; % pilot symbol allocation pattern for Downlink links
scStr.simulation.pilotPatternUplink = ‘LTE Uplink’; % pilot symbol allocation pattern for Uplink links
scStr.simulation.pilotSpacingFrequency = 6; % pilot spacing in frequency domain (may be fractions of subcarriers)
scStr.simulation.pilotSpacingTime = 3.5; % pilot spacing in time domain (may be fraction of symbols)
scStr.simulation.pilotSequenceLength = 12; % length of orthogonal pilot symbol sequence
scStr.simulation.receiverTypeMIMO = ‘MMSE’;

%% MIMO Parameters
% Layer mapping
scStr.layerMapping.mode = ‘5G’;
scStr.layerMapping.table.Uplink = {1;2;[1,2]};
scStr.layerMapping.table.Downlink = {1;2;[1,2]};

% MIMO mode
scStr.modulation.transmissionMode = ‘CLSM’;
scStr.schedule.multiuserMode.Downlink = {‘MUST’}; % per BS. Right now ‘MUST’, ‘ZF-MUMIMO’, ‘BD-MUMIMO’ and ‘MRT-MUMIMO’ are supported
scStr.schedule.multiuserMode.Uplink = {‘none’};
scStr.modulation.delayDiversity = 1;

%% Feedback Parameters
scStr.feedback.delay = 0;
scStr.feedback.averager.Type = ‘miesm’;
scStr.modulation.cqiTable = 0;

% for the custom transmission mode the following parameters are used to configure the feedback
scStr.feedback.enable = true; % this parameter is ignored, the feedback is automatically enabled for the CLSM transmission mode
scStr.feedback.pmi = true;
scStr.feedback.ri = false;
scStr.feedback.cqi = true;

scStr.modulation.nStreams = [2]; % per Link; number of active spatial streams
scStr.modulation.mcs = [15]; % parameter is unused
% Per link, precoder selection (used when feedback is disabled)
scStr.modulation.precodingMatrix{1} = 1/sqrt(2)*eye(2,2); % per Link; employed precoding matrix

% MUST power allocation
scStr.modulation.MUSTIdx = [2]; % per BS; the power allocation index of the 3GPP MUST mode = {0, 1, 2, 3}.

%% Modulation Parameters
% waveform
scStr.modulation.waveform = {‘OFDM’};
scStr.modulation.spreadingTransformDownlink = ‘none’;
scStr.modulation.spreadingTransformUplink = ‘none’;
% parameters for FBMC
scStr.modulation.prototypeFilter = ‘PHYDYAS-OQAM’; % unused for OFDM
% Parameters for UFMC
scStr.modulation.nSubcarriersPerSubband = [12]; % number of subcarriers per subband

% time and bandwidth setup (number of subcarriers, frame duration, CP
% length, sampling rate)
scStr.modulation.numberOfSubcarriers = [72]; % per BS; number of used subcarriers
scStr.modulation.subcarrierSpacing = [15e3]; % per BS; per base station in Hz
scStr.modulation.nSymbolsTotal = [15]; % per BS; total number of time-symbols per frame, the frame duration will be nSymbolsTotal/subcarrierSpacing
scStr.modulation.nGuardSymbols = [1]; % per BS; select how many of the total time-symbols will be used as guard symbols (cyclic prefix in OFDM)
scStr.modulation.samplingRate = ‘Automatic’; % sampling rate has to be the same for all nodes (across all base stations):
% either numeric value for manual setting or ‘Automatic’

%% Channel Coding Parameters
% All links are operating with the same coding parameters, enter it only once.
scStr.coding.code = {‘LDPC’};
scStr.coding.decoding = {‘PWL-Min-Sum’};
scStr.coding.decodingIterations = [16];
scStr.coding.LLRsCalculationMethod = ‘Max-Log’;
scStr.coding.softBufferRatio = [1];

%% Schedule
% static schedule per base station

% BS1 does Orthogonal Multiple Access
scStr.schedule.fixedScheduleDL{1} = []; % schedule for BS1 Downlink
scStr.schedule.fixedScheduleUL{1} = []; % No uplink for BS1.

% BS2 does MUST operation
scStr.schedule.fixedScheduleDL{1} = [‘UE1:36,UE2:36,UE1:UE3,UE2:UE4’]; % schedule for BS2 Downlink
scStr.schedule.fixedScheduleUL{1} = []; % No uplink for BS2.

Regards,
Mohamed Sayed

Hi Mohamed,

This issue relates to how the feedback is assigned to the far user. You can solve this problem by modifying the scheduler as follows:
scStr.schedule.fixedScheduleDL{1} = [‘UE1:36,UE2:36,UE3:UE1,UE4:UE2’];

Best,
Mariam

Dear Mariam,

Thank you for your help.

Regards,
Mohamed

Dear Mariam,

For the same scenario if I want to get plotting for two types of channel coding for comparison. what are the parameters should be adjusted ?
For example comparison between LDPC and Turbo channel coding.

Regards
Mohamed

Hi Mohamed,

The channel coding parameters are defined per link. If you would like the links BS1:UE1 and BS1:UE2 to use LDPC and BS1:UE3 and BS1:UE4 to Turbo, then you have to set the channel coding parameters as follows:

scStr.coding.code = {‘LDPC’, ‘LDPC’, ‘Turbo’, ‘Turbo’}; % per Link; channel
scStr.coding.decoding = {‘PWL-Min-Sum’, ‘PWL-Min-Sum’, ‘Max-Log-MAP’, ‘Max-Log-MAP’}

Best,
Mariam

Dear Mariam,

Thank you for replying.
What are the parameters need to adjust if I want to run the simulation as the following ;

all users ( BS1:UE1, BS1:UE2, BS1:UE3, BS1:UE4) use LDPC channel coding.
and also run a simulation when all users (BS1:UE1, BS1:UE2, BS1:UE3, BS1:UE4) use another type of channel coding for example Turbo.

and get the plotting for two cases in the same figure.

Regards
Mohamed

Hi Mohamed,

You have two options:

  1. You run two simulations, one with LDPC and the second with Turbo coding, and then you copy the content from one figure to the other figure.
  2. You run simulations with two base stations and eight users, and then you set the channel coding parameters as follows:

scStr.coding.code = {‘LDPC’, ‘LDPC’, ‘LDPC’, ‘LDPC’, ‘Turbo’, ‘Turbo’, ‘Turbo’, ‘Turbo’};
scStr.coding.decoding = {‘PWL-Min-Sum’, ‘PWL-Min-Sum’, ‘PWL-Min-Sum’, ‘PWL-Min-Sum’,
‘Max-Log-MAP’, ‘Max-Log-MAP’,‘Max-Log-MAP’, ‘Max-Log-MAP’}

Keep in mind that there will be interference from the other base station for this setting. If you do not want interference, then you have to set scStr.topology.interferenceGeneration to ‘Automatic’ and leave scStr.topology.interferingLinks empty.

Best,
Mariam

Dear Mariam,

Thank you for replying.

With respect to second option it is an easy task.

With respect to first option:
1- Do you mean run two separate simulations with two different scenarios ?
2- How can I copy the content of one figure the the other ?

Regards,
Mohamed

The simulation results are all stored in the results folder. You can write your own function that plots all the results in one figure.

Best,
Mariam