MATLAB: How to use LTE system toolbox to generate reference signal

lteLTE Toolboxsignaluplink

I am trying to generate a 10MHz LTE uplink sounding reference signal with Matlab’s LTE system toolbox. This piece of code shows the parameter set I want to use:
%%SRS config 
ue.DuplexMode = 'FDD'; %ok 



ue.CyclicPrefixUL = 'Normal'; %ok 
ue.NTxAnts = 1; %ok 
ue.NFrame = 10; %? 

ue.NULRB = 50; %ok 
ue.NSubframe = 10; %? 
%%SRS Configuration 
srs = struct; 
srs.NTxAnts = 1; % Number of transmit antennas 
srs.CyclicShift = 0; %ok % UE-cyclic shift 
srs.ConfigIdx = 0; %ok % UE-specific SRS period = 10ms, offset = 0 
<http://srs.bw/ srs.BW> = 0; %ok % UE-specific SRS bandwidth configuration 
srs.HoppingBW = 0; %ok % SRS frequency hopping configuration 
srs.FreqPosition = 0; %ok % Frequency domain position 
srs.SubframeConfig = 15; %ok % Cell-specific SRS period = 5ms, offset = 0 
srs.BWConfig = 0; %ok % Cell-specific SRS bandwidth configuration 
% srs.TxComb = 0; % Even indices for comb transmission 
[srsSeq, srsInfo] = lteSRS(ue,srs); 
% srsInfo(1) 
ZCroot = srsInfo.('RootSeq') 
ZClength = srsInfo.('NZC') 
x_1 = lteZadoffChuSeq(ZCroot, ZClength); 
testcorr = xcorr(x_1, x_1); 
plot(real(testcorr))
I passed two struct arguments to lteSRS and it returns the sequence and info struct. Since I am interested in the CAZAC waveform I used the returned value and passed them to lteZadoffChuSeq which calculates the waveform.
In the next step, I need the waveform to be sampled at 15.36MHz, the way a 10MHz signal would be transmitted by the UE. Does LTE toolbox provide the functionality to perform this last step?

Best Answer

The symbols need to be SC-FDMA modulated (see https://mathworks.com/help/lte/ref/ltescfdmamodulate.html?s_tid=doc_ta) to generate the time-domain waveform sampled at the expected sampling rate. Please see https://mathworks.com/help/lte/examples/uplink-waveform-modeling-using-srs-and-pucch.html which demonstrates how an SRS containing waveform can be generated.
Related Question