Uplink FRC generation using 5g toolbox's NR Test Model Waveform Generation Example

Hello,

I'm using the exapmle provided by 5g toolbox to generate TMs and FRCs waveforms (I have Matlab R2020b). While generating UL FRCs (For exapmle, G-FR1-A1-5) in TDD mode I noticed the allocated symbols in the special slot are ignored. Looking inside the helper functions I found that the special slot is defined as in Table 8.2.1.4.2-2 in 38.141, i.e. 7 DL, 1 S, 4 UL, with symbol allocation for the special slot of 6 DL, 4 G, 4 UL, but after this is defined the special slot is ignored. In the code (hNRReferenceWaveformGenerator, lines 1022-1028):

[~,tp] = getTDDConfiguration(tdef.FR,scs,linkdirection,1); 

tddmask = repmat(tp,1,ceil(pxsch.AllocatedPeriod/length(tp)));  
tddmask = tddmask(1:pxsch.AllocatedPeriod);                             % Mask across allocated period, where DL/UL only slots = 0
tddmask(pxsch.AllocatedSlots+1) = tddmask(pxsch.AllocatedSlots+1)-1;    % Set allocated DL/UL only = -1

pxsch.AllocatedSlots = find(tddmask<0)-1;

Any input on why is it done this way and if it is going to be changed in future releases?

Thanks

Itamar