I have used a Loop as-- bitsIn = randi([0 1], bitsPerSub​Carrier*nu​mDataCarri​ers, 1); symbolsIn = qamMapper(bitsIn); why matlb shows an error like-- Error in fofdmn1 (line 60) symbolsIn = qamMapper(bitsIn);? Please answer me if any alternative.

 bitsIn = randi([0 1], bitsPerSubCarrier*numDataCarriers, 1); 
 symbolsIn = qamMapper(bitsIn);

why matlb shows an error like--

Error in fofdmn1 (line 60) symbolsIn = qamMapper(bitsIn);

[Steven Lord]

Please show the FULL text of the error message -- everything in red. Just copy and paste the message, don't try to summarize or paraphrase it.

[Walter Roberson]

Did you first create qamMapper with a call to comm.RectangularQAMModulator ?

Which MATLAB version are you using?

[MOLLAH KHOKON ALI]

Yes I am first using This comm.RectangularQAMModulator. I am using Matlab R2015a version.

[Walter Roberson]

The ability to use the variable name followed by inputs instead of using step was not until at least R2015b.

[MOLLAH KHOKON ALI]

%QAM symbol mapper
qamMapper = comm.RectangularQAMModulator( ...
    'ModulationOrder', 2^bpsc, 'BitInput', true, ...
    'NormalizationMethod', 'Average power');

%Set up a figure for spectrum plot
hFig = figure('Position', figposition([46 50 30 30]), 'MenuBar', 'none');
axis([-0.5 0.5 -500 -20]);
hold on;
grid on;
xlabel('Normalized Frequecny');
ylabel('PSD(dBW/HZ)');
title(['F-OFDM',num2str(nrbs),'Resource Block',num2str(rbsize),'Subcarrier each']);

%Generate Data Symbol
bitsIn = randi([0 1], bpsc*ndc, 1);
symbolsIn = qamMapper(bitsIn);

Error message like below:

Array formation and parentheses-style indexing with objects of class 'comm.RectangularQAMModulator' is not allowed.
Use objects of class 'comm.RectangularQAMModulator' only as scalars or use a cell array.

Error in fofdm1 (line 75)
symbolsIn = qamMapper(bitsIn);

[MOLLAH KHOKON ALI]

Thank you Mr. Walter Roberson for your kind information.

Answer 1

[Walter Roberson]

You are using a version of MATLAB that is old enough that you need to instead use

   symbolsIn = step(qamMapper, bitsIn);

[MOLLAH KHOKON ALI]

Yes I got the solution.Thank you so much sir.

[Walter Roberson]

Please Accept my answer if the question is resolved.