NB-IoT Uplink Waveform Generation and Analysis
This example shows how to generate and receive a narrowband internet of things (NB-IoT) uplink waveform in the presence of an LTE wideband waveform. The example also analyzes the quality of the received NB-IoT physical uplink shared channel (NPUSCH) through error vector magnitude (EVM) measurements.
Introduction
To support maximum flexibility of the NB-IoT deployment, 3GPP defines these three NB-IoT modes of operation (TS 36.104 Section 3.1):
Standalone — NB-IoT carrier deployed in its own spectrum
Guardband — NB-IoT carrier deployed in the unused resource block(s) within an LTE carrier's guardband
In-band — NB-IoT carrier deployed in resource block(s) of an LTE carrier
This figure shows a sketch of in-band and guardband modes for a 5 MHz LTE carrier.
For the in-band mode of NB-IoT, the NB-IoT component should not overlap with any physical resource block (PRB) allocated for transmitting the physical uplink control channel (PUCCH).
For the guardband mode of NB-IoT, the allowed PRBs depend on the guardband size of the LTE carrier as defined in TS 36.101 Section 5.6. Guardband mode of NB-IoT is not supported on a 1.4 MHz and 3 MHz LTE carrier because the guardband sizes are too small. This table shows the allowed PRB indices for guardband deployment of uplink NB-IoT:
guardbandPRBTable = nbiotAllowedGuardbandPRB()
guardbandPRBTable=6×3 table
LTE Bandwidth Guardband PRBs (Lower Edge) Guardband PRBs (Upper Edge)
___________________ ___________________________ ___________________________
"1.4 MHz ( 6 RBs)" {1×0 double } {1×0 double }
" 3 MHz ( 15 RBs)" {1×0 double } {1×0 double }
" 5 MHz ( 25 RBs)" {[ -1]} {[ 25]}
" 10 MHz ( 50 RBs)" {[ -2 -1]} {[ 50 51]}
" 15 MHz ( 75 RBs)" {[ -4 -3 -2 -1]} {[ 75 76 77 78]}
" 20 MHz (100 RBs)" {[-5 -4 -3 -2 -1]} {[100 101 102 103 104]}
The example shows how to:
Generate an NB-IoT uplink waveform based on a reference test channel.
Receive the NB-IoT waveform in the presence of an LTE wideband waveform.
Measure NPUSCH EVM.
Generating the waveform and the processing it at the receiver to compute the NPUSCH EVM involves these steps:
Simulation Configuration
This example generates the NB-IoT uplink waveform based on a reference test channel, as defined in TS 36.104 Annex A. You can select a reference test channel with the desired subcarrier spacing and number of consecutive subcarriers in a resource unit (RU) for the NPUSCH configuration.
% TS 36.104, Base Station (BS) radio transmission and reception % Annex A.14 - Fixed Reference Channels for NB-IoT reference sensitivity (pi/2 BPSK, R=1/3) % Annex A.15 - Fixed Reference Channels for NB-IoT dynamic range (pi/4 QPSK, R=2/3) % Annex A.16 - Fixed Reference Channels for NB-IoT PUSCH format 1 rcname ="A14-1";
Select the number of uplink resource blocks (RBs), NULRB, and the index of the PRB for NB-IoT allocation, nbiotPRBIndex. To use the in-band operation mode for NB-IoT, specify nbiotPRBIndex as an integer between 0 and NULRB-1. To use the guardband operation mode for NB-IoT, specify nbiotPRBIndex with a valid value from guardbandPRBTable. Any other value of nbiotPRBIndex indicates that the NB-IoT will be out of band.
NULRB =25; nbiotPRBIndex =
-1;
Set the waveform duration in the number of transport blocks. The specified waveform duration applies to the LTE wideband waveform as well.
totNumTrBlks = 1;
NB-IoT Uplink Configuration and Waveform Generation
Use the local function configureNBIoTUplinkWaveform to configure the user equipment (UE) specific configuration, the NPUSCH channel specific configuration, and other required parameters.
ngen = configureNBIoTUplinkWaveform(NULRB,nbiotPRBIndex,RCName=rcname,TotNumTrBlks=totNumTrBlks);
Simulating guardband NB-IoT carrier
Use the local function generateNBIoTUplinkWaveform to generate the NB-IoT waveform. For details about this process, see the NB-IoT Uplink Waveform Generation example.
[nbiotWaveform,nbiotInfo] = generateNBIoTUplinkWaveform(ngen);
Generating 32 slots corresponding to 1 transport block(s) transmitted on NPUSCH
LTE Uplink Configuration and Waveform Generation
Configure and generate the LTE wideband waveform. Use the local function configureWidebandLTEWaveform to configure an LTE wideband waveform with the number of uplink RBs equal to NULRB.
ltecfg = configureWidebandLTEWaveform(NULRB,ngen.TotSubframes,nbiotPRBIndex);
% Generate wideband LTE waveform
trdata = [1 0 0 1];
[lteWaveform,~,lteInfo] = lteRMCULTool(ltecfg,trdata);Waveform Combination
The example combines the NB-IoT and the LTE waveforms in the time domain assuming perfect synchronization between the two waveforms at the base station (BS). The hNBUplinkCombinedWaveform function applies frequency shifting to the NB-IoT waveform to put it in the specified PRB and upsamples the NB-IoT waveform before the combination. This function also plots the power spectra of the upsampled and frequency shifted NB-IoT waveform and the LTE wideband waveform.
% Create the parameter structure needed to combine the waveform OSR = lteInfo.SamplingRate/nbiotInfo.SamplingRate; combParams = struct(); combParams.NULRB = NULRB; combParams.NBIoTPRBIndex = nbiotPRBIndex; combParams.OSR = OSR; combParams.SamplingRate = lteInfo.SamplingRate; % Combine the waveform [combWaveform,offset] = hNBUplinkCombinedWaveform(combParams,lteWaveform,nbiotWaveform);
NB-IoT Receive Filtering
In this section, you:
Apply frequency correction. Shift the received waveform in frequency to bring the NB-IoT spectrum to baseband (0 Hz).
Filter out the LTE component and downsample. Downsample the waveform to the NB-IoT sampling rate and filter out the frequencies outside the NB-IoT band.
Plot the spectrogram of the received waveform. The plot shows the frequency occupied by the NB-IoT component in the received waveform.
rxWaveform = combWaveform; minThreshold = -130 + 20 * double(strcmp(ngen.NBULSubcarrierSpacing,'3.75kHz')); % Threshold for spectrogram figure; spectrogram(rxWaveform(:,1),ones(lteInfo.Nfft,1),0,lteInfo.Nfft,'centered',lteInfo.SamplingRate,'MinThreshold',minThreshold);
Downshifting of NB-IoT Waveform
Downshift the received waveform to bring the NB-IoT component to baseband. The plot shows the power spectrum of the received waveform after the frequency downshifting where the center of the PRB with the NB-IoT component is shifted to 0 Hz.
rxWaveformB = lteFrequencyCorrect(ltecfg,rxWaveform,offset); % Received waveform with NB-IoT in baseband combinedSpecPlotB = spectrumAnalyzer('SampleRate',lteInfo.SamplingRate,'Title','Received Waveform Power Spectrum with NB-IoT in Baseband'); combinedSpecPlotB(rxWaveformB);
Filtering and Downsampling of NB-IoT Waveform
Use the resample function to downsample the baseband received waveform to the nominal NB-IoT sampling rate of 1.92 MHz. The default FIR antialiasing lowpass filter implemented in the resample function filters out the unwanted LTE component without using an additional lowpass filter.
rxwave = resample(rxWaveformB,1,OSR);
Plot the spectrogram of the recovered NB-IoT waveform against the original NB-IoT waveform.
filteredSpecPlot = spectrumAnalyzer('SampleRate',lteInfo.SamplingRate,'Title','Original and Recovered NB-IoT Waveform Power Spectrum', ... 'ChannelNames',{'Original NB-IoT waveform','Recovered NB-IoT waveform'},'ShowLegend',true); filteredSpecPlot([nbiotWaveform,rxwave]);
Plot the spectrogram of the recovered NB-IoT waveform. The plot shows the baseband narrowband waveform after extracting it from the received waveform.
figure; spectrogram(rxwave(:,1),ones(nbiotInfo.Nfft,1),0,nbiotInfo.Nfft,'centered',nbiotInfo.SamplingRate,'MinThreshold',minThreshold);
EVM Measurements
Channel Estimator Configuration for EVM Measurements
Parameterize the channel estimator at the receiver end using the structure cec.
cec = struct(); cec.PilotAverage = 'UserDefined'; % Type of pilot symbol averaging cec.FreqWindow = 23; % Frequency window size in REs cec.TimeWindow = 1; % Time window size in REs cec.InterpType = 'Cubic'; % 2D interpolation type cec.CELength = 1; % Channel estimation length in ms
Process EVM
The hNPUSCHEVM function provides per slot and overall EVM measurements.
[evmmeas,plots] = hNPUSCHEVM(ngen,cec,rxwave,nbiotInfo);
Slot 0: average EVM 0.054%, peak EVM 0.078% Slot 1: average EVM 0.094%, peak EVM 0.152% Slot 2: average EVM 0.076%, peak EVM 0.119% Slot 3: average EVM 0.033%, peak EVM 0.054% Slot 4: average EVM 0.069%, peak EVM 0.088% Slot 5: average EVM 0.057%, peak EVM 0.076% Slot 6: average EVM 0.075%, peak EVM 0.121% Slot 7: average EVM 0.053%, peak EVM 0.078% Slot 8: average EVM 0.047%, peak EVM 0.066% Slot 9: average EVM 0.116%, peak EVM 0.174% Slot 10: average EVM 0.050%, peak EVM 0.068% Slot 11: average EVM 0.057%, peak EVM 0.098% Slot 12: average EVM 0.097%, peak EVM 0.138% Slot 13: average EVM 0.065%, peak EVM 0.077% Slot 14: average EVM 0.034%, peak EVM 0.048% Slot 15: average EVM 0.123%, peak EVM 0.182% Slot 16: average EVM 0.055%, peak EVM 0.097% Slot 17: average EVM 0.089%, peak EVM 0.117% Slot 18: average EVM 0.092%, peak EVM 0.123% Slot 19: average EVM 0.072%, peak EVM 0.125% Slot 20: average EVM 0.082%, peak EVM 0.127% Slot 21: average EVM 0.063%, peak EVM 0.107% Slot 22: average EVM 0.046%, peak EVM 0.075% Slot 23: average EVM 0.040%, peak EVM 0.054% Slot 24: average EVM 0.067%, peak EVM 0.105% Slot 25: average EVM 0.074%, peak EVM 0.092% Slot 26: average EVM 0.045%, peak EVM 0.088% Slot 27: average EVM 0.058%, peak EVM 0.089% Slot 28: average EVM 0.052%, peak EVM 0.092% Slot 29: average EVM 0.036%, peak EVM 0.052% Slot 30: average EVM 0.076%, peak EVM 0.108% Slot 31: average EVM 0.118%, peak EVM 0.178% All 32 slots: average EVM 0.072%, peak EVM 0.182%
References
3GPP TS 36.104. "Evolved Universal Terrestrial Radio Access (E-UTRA); Base Station (BS) Radio Transmission and Reception." 3rd Generation Partnership Project; Technical Specification Group Radio Access Network.
3GPP TS 36.211. "Evolved Universal Terrestrial Radio Access (E-UTRA); Physical Channels and Modulation." 3rd Generation Partnership Project; Technical Specification Group Radio Access Network.
3GPP TS 36.213. "Evolved Universal Terrestrial Radio Access (E-UTRA); Physical Layer Procedures." 3rd Generation Partnership Project; Technical Specification Group Radio Access Network.
Local Functions
function t = nbiotAllowedGuardbandPRB() % Generate a table showing the PRB indices allowed for NB-IoT guardband % deployment which depend on guardband sizes NULRBList = [6 15 25 50 75 100]; % TS 36.101 Section 5.6 bwMHz = [1.4 3 5 10 15 20]; % Bandwidth in MHz bw = (pad(string(bwMHz),'left') + repmat(" MHz (",size(bwMHz)) + pad(string(NULRBList),'left') + repmat(" RBs)",size(bwMHz)))'; % Guardband mode % The allowed PRB indices for NB-IoT guardband mode are derived % here for all channel bandwidths. totalGuardHz = bwMHz*1e6 - NULRBList*12*15e3; % Total guardband in Hz NRBGuard = floor((totalGuardHz/2) / (12*15e3)); % Number of RBs allowed on each side of the guardband for all BWs PRBGuardLow = cellfun(@(x) (-x:-1),num2cell(NRBGuard(:)),'UniformOutput',false); % Allowed PRB indices for lower-edge guardband (0-based) PRBGuardHigh = cellfun(@(x,y) (y+(0:(x-1))),num2cell(NRBGuard(:)),num2cell(NULRBList(:)),'UniformOutput',false); % Allowed PRB indices for upper-edge guardband (0-based) t = table(bw,PRBGuardLow,PRBGuardHigh); t.Properties.VariableNames = ["LTE Bandwidth" "Guardband PRBs (Lower Edge)" "Guardband PRBs (Upper Edge)"]; end function ngen = configureNBIoTUplinkWaveform(NULRB,nbiotPRBIndex,nvargs) % Configure the NB-IoT uplink waveform arguments % Number of uplink RBs, for reporting operation mode only NULRB % PRB index in which NB-IoT is deployed, for reporting operation % mode only nbiotPRBIndex % The RMC or FRC on which the configuration will be based, as % defined in TS 36.101 Annex A or TS 36.104 Annex A nvargs.RCName = 'A14-1'; % Target first subcarrier index of the NPUSCH frequency allocation % in the PRB nvargs.SubcarrierOffset = 0; % Number of repetitions in each NPUSCH codeword nvargs.NRep = 1; % Narrowband physical layer cell identity (PCI) nvargs.NNCellID = 0; % Radio network temporary identifier of the UE nvargs.RNTI = 0; % NPUSCH DM-RS cyclic shift for multi-tone cases nvargs.DMRSCyclicShift = 0; % Total number of transport blocks to transmit in the waveform nvargs.TotNumTrBlks = 1; % RV offset signaled via DCI (TS 36.213 16.5.1.2) nvargs.RVDCI = 0; % Windowing for SC-FDMA modulation (TS 36.104 Table E.5.1-1a) nvargs.Windowing = 3; % NPUSCH power scaling in dB nvargs.NPUSCHPower = 0; % NPUSCH DM-RS power scaling in dB nvargs.NPUSCHDMRSPower = 0; end % Get primary independent parameters for the NPUSCH [ue,chs,tbs] = getBasicRMCDefinition(nvargs.RCName); % Set UE-wide parameters ue.NNCellID = nvargs.NNCellID; ue.DuplexMode = 'FDD'; ue.Windowing = nvargs.Windowing; % Get the number of slots in a single RU according to TS 36.211 Table % 10.1.2.3-1 if strcmpi(chs.NPUSCHFormat,'Data') % format 1 if chs.NRUsc == 1 NULSlots = 16; elseif any(chs.NRUsc == [3 6 12]) NULSlots = 24 / chs.NRUsc; % giving 8/4/2 slots per RU at the associated number of subcarriers else error('Invalid number of subcarriers. NRUsc (%d) must be one of 1,3,6,12.',chs.NRUsc); end elseif strcmpi(chs.NPUSCHFormat, 'Control') % format 2 NULSlots = 4; else error('Invalid NPUSCH format (%s). NPUSCH format must be ''Data'' or ''Control''', chs.NPUSCHFormat); end chs.NULSlots = NULSlots; % NPUSCH channel-specific parameters numSubcarriers = 12*15/str2double(ue.NBULSubcarrierSpacing(1:end-3)); subcarrieroffset = min(nvargs.SubcarrierOffset,numSubcarriers-chs.NRUsc); chs.NBULSubcarrierSet = subcarrieroffset+(0:chs.NRUsc-1); chs.NRep = nvargs.NRep; chs.RNTI = nvargs.RNTI; chs.NSlotsPerBundle = chs.NRU*chs.NULSlots*chs.NRep; chs.CyclicShift = nvargs.DMRSCyclicShift; chs.SeqGroupHopping = 'off'; chs.SeqGroup = 0; chs.SlotIdx = 0; chs.RVDCI = nvargs.RVDCI; chs.NPUSCHPower = nvargs.NPUSCHPower; chs.NPUSCHDMRSPower = nvargs.NPUSCHDMRSPower; % Set the DM-RS base sequence ID according to TS 36.211 Section % 10.1.4.1.2. DM-RS base sequence ID is used for the multi-tone case % (3, 6, 12 tones), while it has no effect for single-tone or disabled % sequence-group hopping cases. if chs.NRUsc == 3 maxBaseSeqIdx = 12; elseif chs.NRUsc == 6 maxBaseSeqIdx = 14; else maxBaseSeqIdx = 30; end chs.BaseSeqIdx = mod(ue.NNCellID,maxBaseSeqIdx); % Calculate waveform duration parameters to be used for waveform % generation if strcmpi(ue.NBULSubcarrierSpacing,'15kHz') NSlotsPerFrame = 20; NSlotsPerSubframe = 2; else NSlotsPerFrame = 5; NSlotsPerSubframe = 0.5; end TotNSlots = nvargs.TotNumTrBlks*chs.NSlotsPerBundle; TotSubframes = TotNSlots/NSlotsPerSubframe; % Set the configuration structure ngen ngen = ue; ngen.TBS = tbs; ngen.TotNumTrBlks = nvargs.TotNumTrBlks; ngen.TotNSlots = TotNSlots; ngen.TotSubframes = TotSubframes; ngen.NSlotsPerFrame = NSlotsPerFrame; ngen.NPUSCH = chs; % Report operation mode if any(nbiotPRBIndex == (0:NULRB-1)) operationMode = 'in-band'; else gbTable = nbiotAllowedGuardbandPRB(); gbPRBs = [gbTable{contains(gbTable{:,1},string(NULRB)+" RBs"),2:3}{:}]; if any(nbiotPRBIndex == gbPRBs) operationMode = 'guardband'; else operationMode = 'out-of-band'; end end fprintf('\nSimulating %s NB-IoT carrier\n',operationMode); end function [ue,chs,tbs] = getBasicRMCDefinition(rcname) % Get the primary independent parameters for the RMC from the RAN4 % RMC/FRC specification tables persistent rclist nl; if isempty(rclist) % TS 36.104 A.14 Fixed Reference Channels for NB-IoT reference sensitivity (pi/2 BPSK, R=1/3) rclistA14 = struct( ... 'RCName',compose('A14-%d',1:2), ... 'TBS',32, ... 'NBULSubcarrierSpacing',{'15kHz','3.75kHz'}, ... 'NRUsc',1, ... 'Modulation','BPSK', ... % (pi/2) BPSK for single tone 'NRU',2, ... % Each NPUSCH instance is 2 RUs of 1x16 'subcarriers x slots x pi/2-BPSK' 'NPUSCHFormat','Data' ... ); % TS 36.104 A.15 Fixed Reference Channels for NB-IoT dynamic range (pi/4 QPSK, R=2/3) rclistA15 = struct( ... 'RCName',compose('A15-%d',1:2), ... 'TBS',104, ... 'NBULSubcarrierSpacing',{'15kHz','3.75kHz'}, ... 'NRUsc',1, ... 'Modulation','QPSK', ... % (pi/4) QPSK for a single tone 'NRU',1, ... % Each NPUSCH instance to 1 RU of 1x16 'subcarriers x slots x pi/4-QPSK' 'NPUSCHFormat','Data' ... ); % TS 36.104 A.16 Fixed Reference Channels for NB-IoT NPUSCH format 1 % A.16.1 One PRB rclistA16_1 = struct( ... 'RCName',compose('A16-%d',1:6), ... 'TBS',{32,32,40,104,136,424}, ... 'NBULSubcarrierSpacing',{'3.75kHz','15kHz','15kHz','15kHz','15kHz','15kHz'}, ... 'NRUsc',{1,1,3,6,12,12}, ... 'Modulation',{'BPSK','BPSK','QPSK','QPSK','QPSK','QPSK'}, ... 'NRU',{2,2,1,1,1,5}, ... 'NPUSCHFormat','Data' ... ); % A16-7 uses 16QAM rclistA16_2 = struct( ... 'RCName','A16-7', ... 'TBS',280, ... 'NBULSubcarrierSpacing','15kHz', ... 'NRUsc',12, ... 'Modulation','16QAM', ... 'NRU',1, ... 'NPUSCHFormat','Data' ... ); % TS 36.101, Annex A.2.4 Reference Measurement Channels for UE Category NB1 rclistA24 = struct( ... 'RCName',compose('R-%d',1:7), ... 'TBS',{32,40,32,40,72,72,72}, ... 'NBULSubcarrierSpacing',{'3.75kHz','3.75kHz','15kHz','15kHz','15kHz','15kHz','15kHz'}, ... 'NRUsc',{1,1,1,1,3,6,12}, ... 'Modulation',{'BPSK','QPSK','BPSK','QPSK','QPSK','QPSK','QPSK'}, ... 'NRU',{2,1,2,1,1,1,1}, ... 'NPUSCHFormat','Data' ... ); % Control (NPUSCH format 2) 'reference' channels (provided here for utility, not 3GPP defined) rclistControl = struct( ... 'RCName',compose('Control-%d',1:2), ... 'TBS',0, ... 'NBULSubcarrierSpacing',{'3.75kHz','15kHz'}, ... 'NRUsc',1, ... 'Modulation','BPSK', ... 'NRU',1, ... 'NPUSCHFormat','Control' ... ); % Combine all the sets of channel definitions into a single structure vector rclist = [rclistA14,rclistA15,rclistA16_1,rclistA16_2,rclistA24,rclistControl]; nl = {rclist.RCName}; % Store all the RMC names contained in the above definitions end % Look-up the definition entry for the required FRC selection = rclist(strcmpi(rcname,nl)); if isempty(selection) error('RC name must be one of %s.', join(string(nl),', ')); end % Parameter field mapping function fv = @(y,v)setfield(y,v,selection.(v)); % Create the UE-specific parameter structure ue = struct(); ue = fv(ue,'NBULSubcarrierSpacing'); % Create the NPUSCH channel-specific structure chs = struct(); chs = fv(chs,'NPUSCHFormat'); chs = fv(chs,'Modulation'); chs = fv(chs,'NRUsc'); chs = fv(chs,'NRU'); % Return the associated TBS tbs = selection.TBS; end function [waveform,info] = generateNBIoTUplinkWaveform(ngen) % Generate the NB-IoT uplink waveform % Get parameters ue = ngen; chs = ngen.NPUSCH; TotNSlots = ngen.TotNSlots; tbs = ngen.TBS; NSlotsPerFrame = ngen.NSlotsPerFrame; % Get the slot grid emptySlotGrid = lteNBResourceGrid(ue); slotGridSize = size(emptySlotGrid); L = slotGridSize(2); % Initialization state = []; trblk = []; nbGrid = repmat(emptySlotGrid,1,TotNSlots); % Display the number of slots being generated fprintf('\nGenerating %d slots corresponding to %d transport block(s) transmitted on NPUSCH\n',TotNSlots,ngen.TotNumTrBlks); % Loop over slots for slotIdx = chs.SlotIdx+(0:TotNSlots-1) % Calculate the frame number and slot number within the frame ue.NFrame = fix(slotIdx/NSlotsPerFrame); ue.NSlot = mod(slotIdx,NSlotsPerFrame); if isempty(trblk) if strcmpi(chs.NPUSCHFormat,'Data') % UL-SCH encoding is done for the two RV values used for % transmitting the codewords. The RV sequence used is % determined from the rvDVI value signaled in the DCI and % alternates between 0 and 2 as given in TS 36.213 Section % 16.5.1.2 % Determine the coded transport block size [~,npuschInfo] = lteNPUSCHIndices(ue,chs); outblklen = npuschInfo.G; if outblklen>0 % Define the transport block which will be encoded to % create the codewords for different RV trblk = randi([0 1],tbs,1); % Create the codewords corresponding to the two RV % values used in the first and second block. This will % be repeated till all blocks are transmitted chs.RV = 2*mod(chs.RVDCI+0,2); % RV for the first block cw = lteNULSCH(chs,outblklen,trblk); % CRC and Turbo coding chs.RV = 2*mod(chs.RVDCI+1,2); % RV for the second block cw = [cw lteNULSCH(chs,outblklen,trblk)]; %#ok<AGROW> % CRC and Turbo coding is repeated else % If the coded transport block size is zero, there is % no transmission in this slot cw = zeros(0,1); end else trblk = randi([0 1],1); % 1 bit ACK; % For ACK, the same codeword is transmitted in every block % as defined in TS 36.212 Section 6.3.3 cw = lteNULSCH(trblk); end blockIdx = 0; % First block to be transmitted thisCw = getCodewordBlock(cw,blockIdx); end % Initialize grid slotRange = (slotIdx-chs.SlotIdx)*L+(1:L); slotGrid = nbGrid(:,slotRange); % Encode NPUSCH and map to the slot grid npuschSym = lteNPUSCH(ue,chs,thisCw,state); npuschInd = lteNPUSCHIndices(ue,chs); slotGrid(npuschInd) = npuschSym*db2mag(chs.NPUSCHPower); % Create DM-RS sequence and map to the slot grid [dmrsSym,state] = lteNPUSCHDRS(ue,chs,state); dmrsInd = lteNPUSCHDRSIndices(ue,chs); slotGrid(dmrsInd) = dmrsSym*db2mag(chs.NPUSCHDMRSPower); % Insert this slot into the waveform grid nbGrid(:,slotRange) = slotGrid; % If a full block is transmitted, increment the clock counter so % that the correct codeword can be selected if state.EndOfBlk blockIdx = blockIdx+1; thisCw = getCodewordBlock(cw,blockIdx); end % Transport block count and re-initialization if state.EndOfTx trblk = []; end end % end of slot loop % Perform SC-FDMA modulation to create time domain baseband waveform ue.CyclicPrefixUL = 'Normal'; [waveform,info] = lteSCFDMAModulate(ue,chs,nbGrid); end function cwOut = getCodewordBlock(cwIn,blockIdx) % Get the slice of the codeword related to the input block index cwOut = cwIn(:,mod(blockIdx,size(cwIn,2))+1); end function ltecfg = configureWidebandLTEWaveform(NULRB,TotSubframe,nbiotPRBIndex) % Configure and generate the wideband LTE waveform with the given % number of uplink RBs, NULRB, the total number of subframes, % TotSubframe, and the PRB index of the PRB reserved for NB-IoT % deployment, nbiotPRBIndex, based on a reference measurement channel % (RMC) as defined in TS 36.104 Annex A % Select a reference measurement channel (RMC) as template ltecfg = struct(); ltecfg.RC = 'A1-3'; % TS 36.104 Annex A ltecfg.NULRB = NULRB; % Set waveform duration ltecfg.TotSubframes = TotSubframe; % Use full band frequency allocation for PUSCH, and reserve the PRB % deployed with the NB-IoT component when operating in the in-band mode prbSet = (0:NULRB-1)'; prbSet(prbSet==nbiotPRBIndex) = []; ltecfg.PUSCH.PRBSet = prbSet; end
