lteULPrecode

UL precoding is a step in the PUSCH processing chain. The chain includes scrambling, symbol mapping, UL precoding, RE mapping, and SC-FDMA modulation.

Create a UE-specific configuration structure, get PUSCH indices, and generate a bit stream sized according to configuration structure.

ue = lteRMCUL('A3-2');
[puschInd, info] = ltePUSCHIndices(ue,ue.PUSCH);
ueDim = lteULResourceGridSize(ue);
bits = randi([0,1],info.G,ue.PUSCH.NLayers);

Perform scrambling, symbol modulation, and UL precoding.

scrBits = lteULScramble(ue,bits);
symbols = lteSymbolModulate(scrBits,ue.PUSCH.Modulation);
precodedSymbols = lteULPrecode(symbols,ue.NULRB);

Generate resource mapping grid, populate the grid with the precoded symbols, and perform SC-FDMA modulation.

grid = lteULResourceGrid(ue);
grid(puschInd) = precodedSymbols;
[timeDomainSig,infoScfdma] = lteSCFDMAModulate(ue,grid);

Generate an SC-FDMA modulated waveform for a three-tone NB-IoT uplink configuration by applying the SC-FDMA processing chain, comprising symbol mapping, UL precoding, and SC-FDMA modulation.

Specify an NB-IoT configuration with ten slots and a subcarrier spacing of 15 kHz.

NSlots = 10;
ue.NBULSubcarrierSpacing = '15kHz';

Set the subcarrier locations and generate random bits for transmission.

chs.NBULSubcarrierSet = 0:2;
bits = randi([0,1],7*NSlots*length(chs.NBULSubcarrierSet)*2,1);

Perform symbol modulation and generate precoded symbols.

symbols = lteSymbolModulate(bits,'QPSK');
precodedSymbols = lteULPrecode(symbols,length(chs.NBULSubcarrierSet),'Subcarrier');

Generate the narrowband resource array

grid = repmat(lteNBResourceGrid(ue),1,NSlots);
grid(chs.NBULSubcarrierSet + 1,:) = reshape(precodedSymbols,length(chs.NBULSubcarrierSet),7*NSlots);

Generate the SC-FDMA modulated waveform for the specified configuration and display its size.

waveform = lteSCFDMAModulate(ue,chs,grid);
size(waveform)

ans = 1×2

        9600           1

Generate an SC-FDMA modulated waveform for a single-tone NB-IoT uplink configuration by applying the SC-FDMA processing chain, comprising symbol mapping, UL precoding, and SC-FDMA modulation.

Specify an NB-IoT configuration with 16 slots and a subcarrier spacing of 3.75 kHz.

NSlots = 16;
ue.NBULSubcarrierSpacing = '3.75kHz';

Specify the channel transmission configuration.

chs = struct('NULSlots',4,'NRU',1,'NRep',4,'SlotIdx',0, ...
    'Modulation','BPSK','NBULSubcarrierSet',41);

Generate random bits for transmission, perform symbol modulation, and generate precoded symbols.

bits = randi([0,1],7*NSlots*length(chs.NBULSubcarrierSet),1);
symbols = lteSymbolModulate(bits,chs.Modulation);
precodedSymbols = lteULPrecode(symbols,length(chs.NBULSubcarrierSet),'Subcarrier');

Generate the narrowband resource array

grid = repmat(lteNBResourceGrid(ue),1,NSlots);
grid(chs.NBULSubcarrierSet+1,:) = reshape(precodedSymbols,length(chs.NBULSubcarrierSet),7*NSlots);

Generate the SC-FDMA modulated waveform for the specified configuration and display its size.

waveform = lteSCFDMAModulate(ue,chs,grid);
size(waveform)

ans = 1×2

       61440           1