how can i solve this problem ?

Question

Baghdadi Aya 2021-10-7

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编辑： Baghdadi Aya 2021-10-8

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I want to process a video by using F_OFDM method , I tried it in a random signal

bitIn= randi([0 1], bitsPerSubCarrier*numDataCarriers, 1);

and I got what I want .

But when I tried to change the input to the video stream (that is converted into a binary stream) ,I got this error :

Error using RectangularQAMModulator

When the BitInput property is set to true, the length of

the input (1) must be an integer multiple of the number

of bits per symbol (6).

- Can s.one help me to solve this ?

clear; close all
%read video
vid = VideoReader('test.mp4');
numberFrames = vid.NumberOfFrames;
n= numberFrames ;
totBit=0;
for i=1:1:n
image = read(vid,i);
B = image(:);
%Conversion frames to binary sequence.
binary_sequence = reshape(dec2bin(typecast(B,'uint8'), 8) - '0', 1, []);
totBit=[totBit,binary_sequence];
end
s = rng(211);       % Set RNG state for repeatability
numFFT = 2048;           % Number of FFT points
numRBs = 100;             % Number of resource blocks
rbSize = 12;             % Number of subcarriers per resource block
cpLen = 72;              % Cyclic prefix length in samples
bitsPerSubCarrier = 6;   % 2: QPSK, 4: 16QAM, 6: 64QAM, 8: 256QAM
snrdB = 15;              % SNR in dB
toneOffset = 2.5;        % Tone offset or excess bandwidth (in subcarriers)
L = 513;                 % Filter length (=filterOrder+1), odd
numDataCarriers = numRBs*rbSize;    % number of data subcarriers in sub-band
halfFilt = floor(L/2);
n = -halfFilt:halfFilt;
% Sinc function prototype filter
pb = sinc((numDataCarriers+2*toneOffset).*n./numFFT);
% Sinc truncation window
w = (0.5*(1+cos(2*pi.*n/(L-1)))).^0.6;
% Normalized lowpass filter coefficients
fnum = (pb.*w)/sum(pb.*w);
% Filter impulse response
h = fvtool(fnum, 'Analysis', 'impulse', ...
    'NormalizedFrequency', 'off', 'Fs', 400e6);
h.CurrentAxes.XLabel.String = 'Time (\mus)';
h.FigureToolbar = 'on';
% Use dsp filter objects for filtering
filtTx = dsp.FIRFilter('Structure', 'Direct form symmetric', ...
    'Numerator', fnum);
filtRx = clone(filtTx); % Matched filter for the Rx
% QAM Symbol mapper
qamMapper = comm.RectangularQAMModulator( ...
    'ModulationOrder', 2^bitsPerSubCarrier, 'BitInput', true, ...
    'NormalizationMethod', 'Average power');
% Generate data symbols
bitsIn = length(totBit)
symbolsIn = qamMapper(bitsIn);
% Pack data into an OFDM symbol
offset = (numFFT-numDataCarriers)/2; % for band center
symbolsInOFDM = [zeros(offset,1); symbolsIn; ...
                 zeros(numFFT-offset-numDataCarriers,1)];
ifftOut = ifft(ifftshift(symbolsInOFDM));
% Prepend cyclic prefix
txSigOFDM = [ifftOut(end-cpLen+1:end); ifftOut];
% Filter, with zero-padding to flush tail. Get the transmit signal
txSigFOFDM = filtTx([txSigOFDM; zeros(L-1,1)]);
% Plot power spectral density (PSD)
[psd,f] = periodogram(txSigFOFDM, rectwin(length(txSigFOFDM)), ...
                      numFFT*2, 1, 'centered');            
hFig = figure('Position', figposition([46 50 30 30]), 'MenuBar', 'figure');                  
plot(f,10*log10(psd));
% Set up a figure for spectrum plot
axis([-0.5 0.5 -100 -20]);
hold on;
xlabel('Normalized frequency');
ylabel('PSD (dBW/Hz)')
title(['F-OFDM, ' num2str(numRBs) ' Resource blocks, '  ...
    num2str(rbSize) ' Subcarriers each'])
% Compute peak-to-average-power ratio (PAPR)
PAPR = comm.CCDF('PAPROutputPort', true, 'PowerUnits', 'dBW');
[~,~,paprFOFDM] = PAPR(txSigFOFDM);
disp(['Peak-to-Average-Power-Ratio for F-OFDM = ' num2str(paprFOFDM) ' dB']);
% Plot power spectral density (PSD) for OFDM signal
[psd,f] = periodogram(txSigOFDM, rectwin(length(txSigOFDM)), numFFT*2, ...
                      1, 'centered');
hFig1 = figure('Position', figposition([46 15 30 30]));
plot(f,10*log10(psd));
axis([-0.5 0.5 -100 -20]);
xlabel('Normalized frequency');
ylabel('PSD (dBW/Hz)')
title(['OFDM, ' num2str(numRBs*rbSize) ' Subcarriers'])
% Compute peak-to-average-power ratio (PAPR)
PAPR2 = comm.CCDF('PAPROutputPort', true, 'PowerUnits', 'dBW');
[~,~,paprOFDM] = PAPR2(txSigOFDM);
disp(['Peak-to-Average-Power-Ratio for OFDM = ' num2str(paprOFDM) ' dB']);
% Add AWGN
rxSig = awgn(txSigFOFDM, snrdB, 'measured');
% Receive matched filter
rxSigFilt = filtRx(rxSig);
% Account for filter delay
rxSigFiltSync = rxSigFilt(L:end);
% Remove cyclic prefix
rxSymbol = rxSigFiltSync(cpLen+1:end);
% Perform FFT
RxSymbols = fftshift(fft(rxSymbol));
% Select data subcarriers
dataRxSymbols = RxSymbols(offset+(1:numDataCarriers));
% Plot received symbols constellation
switch bitsPerSubCarrier
    case 2  % QPSK
        refConst = qammod((0:3).', 4, 'UnitAveragePower', true);
    case 4  % 16QAM
        refConst = qammod((0:15).', 16,'UnitAveragePower', true);
    case 6  % 64QAM
        refConst = qammod((0:63).', 64,'UnitAveragePower', true);
    case 8  % 256QAM
        refConst = qammod((0:255).', 256,'UnitAveragePower', true);
end
constDiagRx = comm.ConstellationDiagram( ...
    'ShowReferenceConstellation', true, ...
    'ReferenceConstellation', refConst, ...
    'Position', figposition([20 15 30 40]), ...
    'EnableMeasurements', true, ...
    'MeasurementInterval', length(dataRxSymbols), ...
    'Title', 'F-OFDM Demodulated Symbols', ...
    'Name', 'F-OFDM Reception', ...
    'XLimits', [-1.5 1.5], 'YLimits', [-1.5 1.5]);
constDiagRx(dataRxSymbols);
% Channel equalization is not necessary here as no channel is modeled
% Demapping and BER computation
qamDemod = comm.RectangularQAMDemodulator('ModulationOrder', ...
    2^bitsPerSubCarrier, 'BitOutput', true, ...
    'NormalizationMethod', 'Average power');
BER = comm.ErrorRate;
% Perform hard decision and measure errors
rxBits = qamDemod(dataRxSymbols);
ber = BER(bitsIn, rxBits);
disp(['F-OFDM Reception, BER = ' num2str(ber(1)) ' at SNR = ' ...
    num2str(snrdB) ' dB']);