Модуляция OFDM

using Pkg
using EngeeComms
using EngeeDSP

function rectpulse(x, Nsamp)
    sizex = zeros(Int64, 2);
    sizex[1] = size(x)[1];
    if length(size(x)) == 1
        sizex[2] = 1;
    else sizex[2] = size(x)[2]
    end 

    if ( (sizex[1] == 1) && (sizex[2]!=1) )
        y = reshape(ones(Nsamp,1)*reshape(x, 1, sizex[1]*sizex[2]),sizex[1], sizex[2]*Nsamp);
    else
        y = reshape(ones(Nsamp,1)*reshape(x, 1, sizex[1]*sizex[2]),sizex[1]*Nsamp, sizex[2]);
    end
    return y;
end


function helperPlotMultipath()
    msgLen = 32768;
    fs = 1e7;         
    interpFactor = 2; 
    decimFactor = 32;
    knownBits = [1 0 1 0]';
    var_rand = RandomIntegerGenerator(SetSize=2,InitialSeed=1234,SampleTime=1.0,SamplesPerFrame=msgLen-length(knownBits));
    hiRateMsg = rectpulse([knownBits; var_rand(0.0)],interpFactor) .- 0.5; 
    shortLen = length(hiRateMsg);
    lowRateMsg = rectpulse(hiRateMsg[1:Int64(shortLen/decimFactor)],decimFactor);
    mpChan = [0.8 zeros(1,interpFactor-1) -0.5 zeros(1,interpFactor-1) 0.34]';
    fillLen = length(lowRateMsg)-length(mpChan);
    mpChan = [mpChan; zeros(fillLen,1)];
    mpChanSpecAn = 1e6*mpChan;
    nSamp = 128;
    time = 1e6 * (0:1/fs:(nSamp-1)/fs);
    hrsig = plot(time,hiRateMsg[1:nSamp],linecolor = :green, label = "Высокоскоростной сигнал");
    lrsig = plot!(time,lowRateMsg[1:nSamp],linecolor = :blue, label = "Низкоскоростной сигнал");
        ylims!(-1,1);
        #title!("Низкоскоростной сигнал,Высокоскоростной сигнал, и Импульсная характеристика канала");
        xlabel!("Время (микросек.)");
        ylabel!("Амплитуда");


    # Построение спектра сигналов
    var_fft = EngeeFFT();
    var_fftshift = EngeeFFTshift();
    freq = [-5e6:10e6/65535:5e6...];

    spec_hiRateMsg = EngeeDSP.step!(var_fftshift,abs.(EngeeDSP.step!(var_fft, hiRateMsg))); 
    spec_mpChan = EngeeDSP.step!(var_fftshift,abs.(EngeeDSP.step!(var_fft, mpChan)));
    spec_lowRateMsg = EngeeDSP.step!(var_fftshift,abs.(EngeeDSP.step!(var_fft, lowRateMsg)));
    hrspec =  plot(freq, 20log10.(abs.(spec_hiRateMsg./3e2)), linecolor = :green, label = "Высокоскоростной сигнал" );
    lrspec = plot!(freq, 20log10.(abs.(spec_lowRateMsg./3e2)), linecolor = :blue, label = "Низкоскоростной сигнал");
    freqresp = plot!(freq, 20log10.(abs.(spec_mpChan./1e2)), linecolor = :red, label = "Частотная характеристика канала");
        ylims!(-55,20);
        xlabel!("Частота (Гц)");
        ylabel!("дБм");


    display(hrsig), display(hrspec); 
end