% IEE2620 Lab 2
% DL synchronization signals: SS/PBCH

%Fig.1 grid for normal CP
%Fig.2 grid for extended CP
%Fig.3 DL waveform for normal CP
%Fig.4 DL waveform for extended CP

clc
clear

%variables
mu=2;% NR numerology, 0,1,2,3,4
SCS=15*2^mu; %kHz
NumRBs=20; %frequency scale
CPref1="normal"; %cyclic prefix
CPref2="extended"; %cyclic prefix
BWPSize=NumRBs*SCS*12*0.001; %used BW size in MHz
FR='FR1'; % 'FR1' or 'FR2'; frequency range
ncellid=1;


%% create grid for slot

% normal CP:
carrier1 = nrCarrierConfig("CyclicPrefix",CPref1,"SubcarrierSpacing",SCS,"NSizeGrid",NumRBs,'NSlot',1);
% extended CP:
carrier2 = nrCarrierConfig("CyclicPrefix",CPref2,"SubcarrierSpacing",SCS,"NSizeGrid",NumRBs,'NSlot',1);

grid1=nrResourceGrid(carrier1);
info1 = nrOFDMInfo(carrier1); % Get OFDM information for the specified carrier configuration.
numSym1=info1.SlotsPerFrame*info1.SymbolsPerSlot; %number of total symbols in frame


%display grid1
figure(1)
clf
imagesc([0 carrier1.SymbolsPerSlot-1],[0 carrier1.NSizeGrid*12-1],abs(grid1(:,:,1)));
axis xy;title("Resource grid (Normal CP)");ylabel("Subcarrier");xlabel("OFDM Symbol")
colorbar('Ticks',[0,1,2,3,4],...
      'Ticklabels', {'','', '','',''},...
      'Location', 'eastoutside');


grid2=nrResourceGrid(carrier2);
info2 = nrOFDMInfo(carrier2); % Get OFDM information for the specified carrier configuration.
numSym2=info2.SlotsPerFrame*info2.SymbolsPerSlot; %number of total symbols in frame

%display grid2
figure(2)
clf
imagesc([0 carrier2.SymbolsPerSlot-1],[0 carrier2.NSizeGrid*12-1],abs(grid2(:,:,1)));
axis xy;title("Resource grid (Extended CP)");ylabel("Subcarrier");xlabel("OFDM Symbol")
colorbar('Ticks',[0,1,2,3,4],...
      'Ticklabels', {'','', '','',''},...
      'Location', 'eastoutside');






%% create grid for frame
figure(1)
clf
RBgrid1 = [];
for nslot = 0:(info1.SlotsPerFrame - 1)
    carrier1.NSlot = nslot;
    slotGrid = nrResourceGrid(carrier1);
%    ind = nrSRSIndices(carrier,srs);
%    sym = nrSRS(carrier,srs);
%    slotGrid(ind) = sym;
    RBgrid1 = [RBgrid1 slotGrid];
end

imagesc([0 (carrier1.SymbolsPerSlot*carrier1.SlotsPerFrame)-1],[0 carrier1.NSizeGrid*12-1],abs(RBgrid1(:,:,1)));
axis xy;title("Resource grid for Frame (Normal CP)");ylabel("Subcarrier");xlabel("OFDM Symbol")
colorbar('Ticks',[0,1,2,3,4],...
      'Ticklabels', {'','', '','',''},...
      'Location', 'eastoutside');

figure(2)
clf
RBgrid2 = [];
for nslot = 0:(info2.SlotsPerFrame - 1)
    carrier2.NSlot = nslot;
    slotGrid = nrResourceGrid(carrier2);
%    ind = nrSRSIndices(carrier,srs);
%    sym = nrSRS(carrier,srs);
%    slotGrid(ind) = sym;
    RBgrid2 = [RBgrid2 slotGrid];
end

imagesc([0 (carrier2.SymbolsPerSlot*carrier2.SlotsPerFrame)-1],[0 carrier2.NSizeGrid*12-1],abs(RBgrid2(:,:,1)));
axis xy;title("Resource grid for Frame (Extended CP)");ylabel("Subcarrier");xlabel("OFDM Symbol")
colorbar('Ticks',[0,1,2,3,4],...
      'Ticklabels', {'','', '','',''},...
      'Location', 'eastoutside');



%% waveform
SCScarrier=nrSCSCarrierConfig("NSizeGrid",NumRBs,"SubcarrierSpacing",SCS);
bwp1 = nrWavegenBWPConfig("NSizeBWP",NumRBs,'NStartBWP',SCScarrier.NStartGrid+0,"SubcarrierSpacing",SCS,"CyclicPrefix","normal");
bwp2 = nrWavegenBWPConfig("NSizeBWP",NumRBs,'NStartBWP',SCScarrier.NStartGrid+0,"SubcarrierSpacing",SCS,"CyclicPrefix","extended");


%% Physical channels and signals for waveform
ssb=nrWavegenSSBurstConfig("Enable",0);
pdcch = nrWavegenPDCCHConfig("Enable",0);
pdsch = nrWavegenPDSCHConfig("Enable",0);
%csirs = nrCSIRSConfig;
pusch = nrWavegenPUSCHConfig("Enable",0);
pucch = nrWavegenPUCCH0Config("Enable",0);
srs = nrWavegenSRSConfig("Enable",0);

figure(3)
clf
RBgridDL1=nrDLCarrierConfig("SCSCarriers",{SCScarrier},"BandwidthParts",{bwp1},'SSBurst',ssb,'PDCCH',{pdcch},'PDSCH',{pdsch},'FrequencyRange',FR);%,'CSIRS',{csirs})
[waveformDL,DLinfo1] = nrWaveformGenerator(RBgridDL1);
nfftDL1=DLinfo1.ResourceGrids(1).Info.Nfft;
samplerateDL1 = DLinfo1.ResourceGrids(1).Info.SampleRate;
spectrogram(waveformDL(:,1),ones(nfftDL1,1),0,nfftDL1,'centered',samplerateDL1,'yaxis','MinThreshold',-130);
title('Spectrogram of NR DL Waveform (Normal CP)',strcat('BW=',num2str(BWPSize),' MHz, ', num2str(info1.SymbolsPerSlot),' OFDM symbols'));



figure(4)
clf
RBgridDL2=nrDLCarrierConfig("SCSCarriers",{SCScarrier},"BandwidthParts",{bwp2},'SSBurst',ssb,'PDCCH',{pdcch},'PDSCH',{pdsch},'FrequencyRange',FR);%,'CSIRS',{csirs})
[waveformDL,DLinfo2] = nrWaveformGenerator(RBgridDL2);
nfftDL2=DLinfo2.ResourceGrids(1).Info.Nfft;
samplerateDL2 = DLinfo2.ResourceGrids(1).Info.SampleRate;
spectrogram(waveformDL(:,1),ones(nfftDL2,1),0,nfftDL2,'centered',samplerateDL2,'yaxis','MinThreshold',-130);
title('Spectrogram of NR DL Waveform (Extended CP)',strcat('BW=',num2str(BWPSize),' MHz, ', num2str(info2.SymbolsPerSlot),' OFDM symbols'));


figure(5) %%single block
clf

colorbar('Ticks',[0,1,2,3,4],...
      'Ticklabels', {'','', '','',''},...
      'Location', 'eastoutside');


%% tasks 
% [1] Synchronization Signal Blocks and Bursts [MATLAB] https://se.mathworks.com/help/5g/gs/synchronization-signal-blocks-and-bursts.html 
% step-by-step update figures 1-4


% 1) PSS

ssblock=zeros([240 4]);
pssSymbols=nrPSS(ncellid);
pssIndices=nrPSSIndices;
ssblock(pssIndices)=1*pssSymbols;


figure(5) % ssblock (4x240)
clf
imagesc(abs(ssblock));
clim([0 5]);

axis xy;
xticks(1:4); xticklabels({'0','1','2','3'});
yticks([1 57 183 240]); yticklabels({'0','56','182','240'});
xlabel('OFDM symbol (relative)');
ylabel('Subcarrier (relative)');
title('SS/PBCH block containing PSS');
colorbar('Ticks',[0,1,2,3,4],...
      'Ticklabels', {'Unassigned','PSS', '','',''},...
      'Location', 'eastoutside');


% 2) SSS
sssSymbols = nrSSS(ncellid);
sssIndices = nrSSSIndices;
ssblock(sssIndices) = 2 * sssSymbols;

figure(5) % ssblock (4x240)
clf
imagesc(abs(ssblock));
clim([0 5]);

axis xy;
xticks(1:4); xticklabels({'0','1','2','3'});
yticks([1 57 183 240]); yticklabels({'0','56','182','240'});
xlabel('OFDM symbol (relative)');
ylabel('Subcarrier (relative)');
title('SS/PBCH block containing PSS and SSS');
colorbar('Ticks',[0,1,2,3,4],...
      'Ticklabels', {'Unassigned','PSS', 'SSS','',''},...
      'Location', 'eastoutside');


% 3) PBCH
cw = randi([0 1],864,1);
v = 0;
pbchSymbols = nrPBCH(cw,ncellid,v);
pbchIndices = nrPBCHIndices(ncellid);
ssblock(pbchIndices) = 3 * pbchSymbols;

figure(5)
imagesc(abs(ssblock));
clim([0 5]);
axis xy;
xticks(1:4); xticklabels({'0','1','2','3'});
yticks([1 57 183 240]); yticklabels({'0','56','182','240'});
xlabel('OFDM symbol (relative)');
ylabel('Subcarrier (relative)');
title('SS/PBCH block containing PSS, SSS and PBCH');
colorbar('Ticks',[0,1,2,3,4],...
      'Ticklabels', {'Unassigned','PSS', 'SSS','PBCH',''},...
      'Location', 'eastoutside');



% 4) DM-RS
ibar_SSB = 0;
dmrsSymbols = nrPBCHDMRS(ncellid,ibar_SSB);
dmrsIndices = nrPBCHDMRSIndices(ncellid);
ssblock(dmrsIndices) = 4 * dmrsSymbols;

figure(5)
imagesc(abs(ssblock));
clim([0 5]);
axis xy;
xlabel('OFDM symbol');
ylabel('Subcarrier');
title('SS/PBCH block containing PSS, SSS, PBCH and PBCH DM-RS');
colorbar('Ticks',[0,1,2,3,4],...
      'Ticklabels', {'Unassigned','PSS', 'SSS','PBCH','DM-RS'},...
      'Location', 'eastoutside');