% Lab 1
% create empty resource grid

clc
clear

%variables
mu=0;% NR numerology, 0,1,2,3,4
SCS=15*2^mu; %kHz
NumRBs=4; %frequency scale
CPref="normal";
symPerSlot=14;
BWPSize=NumRBs*SCS*12*0.001; %used BW size
FR='FR1'; % 'FR1' or 'FR2'


%% create grid for slot
carrier = nrCarrierConfig("CyclicPrefix",CPref,"SubcarrierSpacing",SCS,"NSizeGrid",NumRBs,'NSlot',1);

grid=nrResourceGrid(carrier);
info = nrOFDMInfo(carrier); % Get OFDM information for the specified carrier configuration.
numSlotsPerFrame=info.SlotsPerFrame;
numSym=symPerSlot*numSlotsPerFrame; %number of total symbols in frame

%display grid
figure(1)
clf
mesh(abs(grid))
view(2)
axis xy;
title("Resource grid");
ylabel("Subcarrier");
xlabel("OFDM Symbol");


figure(2)
clf
imagesc([0 carrier.SymbolsPerSlot-1],[0 carrier.NSizeGrid*12-1],abs(grid(:,:,1)));
axis xy;
title("Resource grid");
ylabel("Subcarrier");
xlabel("OFDM Symbol");

%% create grid for frame
figure(3)
clf
RBgrid = [];
for nslot = 0:(numSlotsPerFrame - 1)
    carrier.NSlot = nslot;
    slotGrid = nrResourceGrid(carrier);
%    ind = nrSRSIndices(carrier,srs);
%    sym = nrSRS(carrier,srs);
%    slotGrid(ind) = sym;
    RBgrid = [RBgrid slotGrid];
end

mesh(abs(RBgrid))
view(2)
axis xy;
title("Resource grid for Frame");
ylabel("Subcarrier");
xlabel("OFDM Symbol");

figure(4)
clf
imagesc([0 (carrier.SymbolsPerSlot*carrier.SlotsPerFrame)-1],[0 carrier.NSizeGrid*12-1],abs(RBgrid(:,:,1)));
axis xy;
title("Resource grid for Frame");
ylabel("Subcarrier");
xlabel("OFDM Symbol");



%% waveform
SCScarrier=nrSCSCarrierConfig("NSizeGrid",NumRBs,"SubcarrierSpacing",SCS);
bwp = nrWavegenBWPConfig("NSizeBWP",NumRBs,'NStartBWP',SCScarrier.NStartGrid+0,"SubcarrierSpacing",SCS);
ssb=nrWavegenSSBurstConfig("Enable",0);
pdcch = nrWavegenPDCCHConfig("Enable",0);
pdsch = nrWavegenPDSCHConfig("Enable",0);
pusch = nrWavegenPUSCHConfig("Enable",0);
pucch = nrWavegenPUCCH0Config("Enable",0);
srs = nrWavegenSRSConfig("Enable",0);

figure(5)
clf
RBgridUL=nrULCarrierConfig("SCSCarriers",{SCScarrier},'BandwidthParts',{bwp},'PUSCH',{pusch},'PUCCH',{pucch},'SRS',{srs},'FrequencyRange',FR);
[waveformUL,ULinfo] = nrWaveformGenerator(RBgridUL);
nfftUL=ULinfo.ResourceGrids(1).Info.Nfft;
samplerateUL = ULinfo.ResourceGrids(1).Info.SampleRate;
spectrogram(waveformUL(:,1),ones(nfftUL,1),0,nfftUL,'centered',samplerateUL,'yaxis','MinThreshold',-130);
title('Spectrogram of NR UL Waveform',strcat('BW=',num2str(BWPSize),' MHz, ', num2str(numSym),' OFDM symbols'));


figure(6)
clf
RBgridDL=nrDLCarrierConfig("SCSCarriers",{SCScarrier},"BandwidthParts",{bwp},'SSBurst',ssb,'PDCCH',{pdcch},'PDSCH',{pdsch},'FrequencyRange',FR);%,'CSIRS',{csirs})
[waveformDL,DLinfo] = nrWaveformGenerator(RBgridDL);
nfftDL=DLinfo.ResourceGrids(1).Info.Nfft;
samplerateDL = DLinfo.ResourceGrids(1).Info.SampleRate;
spectrogram(waveformDL(:,1),ones(nfftDL,1),0,nfftDL,'centered',samplerateDL,'yaxis','MinThreshold',-130);
title('Spectrogram of NR DL Waveform',strcat('BW=',num2str(BWPSize),' MHz, ', num2str(numSym),' OFDM symbols'));



%% tasks