Added Matlab tests to verify PDSCH BLER

matlab/tests/dlsch_test.m

@@ -4,44 +4,24 @@ pdschConfig=struct('Modulation','64QAM','RV',1,'TxScheme','Port0','NTurboDecIts'
 
 addpath('../../build/srslte/lib/phch/test')
 
-%TBs=18336;
+TBs=18336;
 i=1;
 e_bits=3450*6;
-%error=zeros(size(TBs));
+error=zeros(size(TBs));
-%for i=1:length(TBs)
+for i=1:length(TBs)
-    %trblkin=randi(2,TBs(i),1)-1;
+    trblkin=randi(2,TBs(i),1)-1;
-    trblkin=read_uchar('../../build/data_in');
-    
-    fprintf('e_bits=%d, trblkin=%d\n',e_bits,length(trblkin));
     
     [mat, info]=lteDLSCH(enbConfig,pdschConfig,e_bits,trblkin);
     lib=srslte_dlsch_encode(enbConfig,pdschConfig,e_bits,trblkin);
     error(i)=mean(abs(double(mat)-double(lib)));    
-    mat(mat==0)=-1;
-    mat=mat*10;
-    
-    rec = lteRateRecoverTurbo(mat,length(trblkin),pdschConfig.RV);
-    rec2 = reshape(reshape(rec{1},[],3)',[],1);
-    out = lteTurboDecode(rec{1});
     
-    x=read_int16('../../build/rmout_0.dat');
+end
-    subplot(2,1,1)
-    plot(abs(double(x)-double(rec2)));
-    t=1:100;
-    %plot(t,double(x(t)),t,double(rec2(t)))
-    subplot(2,1,2)
-    llr=read_int16('../../build/llr.dat');
-    plot(abs(double(mat)-double(llr)))
  
-    [data, crc,state] = lteDLSCHDecode(enbConfig, pdschConfig, length(trblkin), mat);
+ if (length(TBs) == 1)
-    disp(crc)
+     disp(info)
-%end
+     disp(error)
-% 
+     n=1:length(mat);
-% if (length(TBs) == 1)
+     plot(abs(double(mat)-double(lib)))
-%     %disp(info)
+ else
-%     disp(error)
+     plot(error)
-%     n=1:length(mat);
+ end
-%     plot(abs(double(mat)-double(lib)))
-% else
-%     plot(error)
-% end

matlab/tests/pdsch_bler.m

@@ -1,158 +1,108 @@
-%% PDSCH decoding based on RMC channels
+%% Plot PDSCH BLER vs SNR for PDSCH without equalization
-
+clear
-%% Cell-Wide Settings
+transportBlkSize=75376;
-% A structure |enbConfig| is used to configure the eNodeB.
+modulation='64QAM';
-%clear12
+rvValues=[0 2 3 1];
-
+SNR=linspace(-2.9,-2.0,8);
-recordedSignal=[];
+Nblocks=30;
-
-Npackets = 20;
-SNR_values = linspace(2,6,10);
-
-Lp=12;
-N=256;
-K=180;
-rstart=(N-K)/2;
-P=K/6;
-Rhphp=zeros(P,P);
-Rhhp=zeros(K,P);
-Rhh=zeros(K,K);
-
-t=0:Lp-1;
-alfa=log(2*Lp)/Lp;
-c_l=exp(-t*alfa);
-c_l=c_l/sum(c_l);
-C_l=diag(1./c_l);
-prows=rstart+(1:6:K);
-
-F=dftmtx(N);
-F_p=F(prows,1:Lp);
-F_l=F((rstart+1):(K+rstart),1:Lp);
-Wi=(F_p'*F_p+C_l*0.01)^(-1);
-W2=F_l*Wi*F_p';
-w2=reshape(transpose(W2),1,[]);
-
-
-%% Choose RMC 
-[waveform,rgrid,rmccFgOut] = lteRMCDLTool('R.0',[1;0;0;1]);
-waveform = sum(waveform,2);
-
-if ~isempty(recordedSignal)
-    rmccFgOut = struct('CellRefP',1,'NDLRB',100,'DuplexMode','FDD','CyclicPrefix','Normal'); 
-    rmccFgOut.PDSCH.RNTI = 1234;
-    rmccFgOut.PDSCH.PRBSet = repmat(transpose(0:rmccFgOut.NDLRB-1),1,2);
-    rmccFgOut.PDSCH.TxScheme = 'Port0';
-    rmccFgOut.PDSCH.NLayers = 1;   
-    rmccFgOut.PDSCH.NTurboDecIts = 5;
-    rmccFgOut.PDSCH.Modulation = {'64QAM'};
-    trblklen=75376;
-    rmccFgOut.PDSCH.TrBlkSizes = trblklen*ones(10,1);
-    rmccFgOut.PDSCH.RV = 0;
-end
-
-flen=rmccFgOut.SamplingRate/1000;
-    
-Nsf = 9; 
-
-%% Setup Fading channel model 
-cfg.Seed = 0;                  % Random channel seed
-cfg.NRxAnts = 1;               % 1 receive antenna
-cfg.DelayProfile = 'EPA';      % EVA delay spread
-cfg.DopplerFreq = 5;           % 120Hz Doppler frequency
-cfg.MIMOCorrelation = 'Low';   % Low (no) MIMO correlation
-cfg.InitTime = 0;              % Initialize at time zero
-cfg.NTerms = 16;               % Oscillators used in fading model
-cfg.ModelType = 'GMEDS';       % Rayleigh fading model type
-cfg.InitPhase = 'Random';      % Random initial phases
-cfg.NormalizePathGains = 'On'; % Normalize delay profile power 
-cfg.NormalizeTxAnts = 'On';    % Normalize for transmit antennas
-cfg.SamplingRate = rmccFgOut.SamplingRate; 
-
-% Setup channel equalizer
-cec.PilotAverage = 'UserDefined';     % Type of pilot averaging
-cec.FreqWindow = 9;                   % Frequency window size
-cec.TimeWindow = 9;                   % Time window size
-cec.InterpType = 'linear';             % 2D interpolation type
-cec.InterpWindow = 'Causal';        % Interpolation window type
-cec.InterpWinSize = 1;                % Interpolation window size
 
 addpath('../../build/srslte/lib/phch/test')
 
-decoded = zeros(size(SNR_values));
+% Subframe configuration
-decoded_srslte = zeros(size(SNR_values));
+enbConfig.NCellID = 100;
-
+enbConfig.CyclicPrefix = 'Normal';
-for snr_idx=1:length(SNR_values)
+enbConfig.NSubframe = 1;
-    SNRdB = SNR_values(snr_idx);
+enbConfig.CellRefP = 1;
-    SNR = 10^(SNRdB/10);    % Linear SNR  
+enbConfig.NDLRB = 100;
-    N0  = 1/(sqrt(2.0*rmccFgOut.CellRefP*double(rmccFgOut.Nfft))*SNR);
+enbConfig.CFI = 1; 
-    
+enbConfig.DuplexMode='FDD';
-    Rhphp=zeros(30,30);
+
-    Rhhp=zeros(180,30);
+% Transmission mode configuration for PDSCH
-
+pdschConfig.NLayers = 1;
-    for i=1:Npackets
+pdschConfig.TxScheme = 'Port0';
-
+pdschConfig.Modulation = {modulation};
-        if isempty(recordedSignal)
+pdschConfig.RNTI = 100;
+pdschConfig.NTurboDecIts = 5;
+pdschConfig.PRBSet = (0:enbConfig.NDLRB-1)';
+
+switch (modulation)
+    case 'QPSK'
+        bitsPerSym = 2;
+    case '16QAM'
+        bitsPerSym = 4;
+    case '64QAM'
+        bitsPerSym = 6;
+end
+noiseVarfactor = sqrt(2*bitsPerSym);
+snr = 10.^(SNR/10);
 
-            %% Fading
+nErrors_mat = zeros(length(SNR),length(rvValues));
-            %rxWaveform = lteFadingChannel(cfg,waveform);
+nErrors_srs = zeros(length(SNR),length(rvValues));
-            rxWaveform = waveform; 
         
-            %% Noise Addition
+for k = 1:length(SNR);
-            noise = N0*complex(randn(size(rxWaveform)), randn(size(rxWaveform)));  % Generate noise
+    subframe=cell(length(rvValues));
-            rxWaveform = rxWaveform + noise; 
+    pdschIdx=ltePDSCHIndices(enbConfig,pdschConfig,pdschConfig.PRBSet);
-        else        
+    for i=1:length(rvValues)
-            rxWaveform = recordedSignal; 
+        subframe{i} = lteDLResourceGrid(enbConfig);
+    end
+    blkCounter = 0;
+    for l = 1:Nblocks;
+        % DL-SCH data bits
+        dlschBits = randi([0 1],transportBlkSize,1);
+        softBuffer = {};     
+        for rvIndex = 1:length(rvValues)
+            % DLSCH transport channel
+            pdschConfig.RV = rvValues(rvIndex);
+            pdschPayload = lteDLSCH(enbConfig, pdschConfig, length(pdschIdx)*bitsPerSym, dlschBits);
+
+            % PDSCH modulated symbols
+            pdschSymbols = ltePDSCH(enbConfig, pdschConfig, pdschPayload);
+            pdschSize = size(pdschSymbols);
+
+            % Addition of noise
+            noise = (1/noiseVarfactor)*sqrt(1/snr(k))*complex(randn(pdschSize),randn(pdschSize));
+            noisySymbols = pdschSymbols + noise;
+
+            subframe{rvIndex}(pdschIdx)=noisySymbols;
+            
+            % PDSCH Rx-side
+            rxCW = ltePDSCHDecode(enbConfig, pdschConfig, noisySymbols);
+            
+            % DL-SCH turbo decoding
+            [rxBits, blkCRCerr, softBuffer] = lteDLSCHDecode(enbConfig, pdschConfig, transportBlkSize, rxCW{1}, softBuffer);
+            
+            % Add errors to previous error counts
+            nErrors_mat(k,rvIndex) = nErrors_mat(k,rvIndex)+blkCRCerr;             
         end
         
-        %% Demodulate 
+        % Same with srsLTE 
-        frame_rx = lteOFDMDemodulate(rmccFgOut, rxWaveform);
+        [okSRSLTE, data, pdschRx, pdschSymbols, cws] = srslte_pdsch(enbConfig, pdschConfig, ...
-
+            transportBlkSize, subframe, ones(size(subframe{1})), 0);
-        for sf_idx=0:Nsf-1
-       % sf_idx=9;
-            subframe_rx=frame_rx(:,sf_idx*14+1:(sf_idx+1)*14);
-            rmccFgOut.NSubframe=sf_idx;
-            rmccFgOut.TotSubframes=1;
-
-            % Perform channel estimation
-            [hest, nest,estimates] = lteDLChannelEstimate2(rmccFgOut, cec, subframe_rx);
-
-            [cws,symbols] = ltePDSCHDecode(rmccFgOut,rmccFgOut.PDSCH,subframe_rx,hest,nest);
-            [trblkout,blkcrc,dstate] = lteDLSCHDecode(rmccFgOut,rmccFgOut.PDSCH, ... 
-                                                    rmccFgOut.PDSCH.TrBlkSizes(sf_idx+1),cws);
-
-            decoded(snr_idx) = decoded(snr_idx) + ~blkcrc;
-
-
-            %% Same with srsLTE
-            if (rmccFgOut.PDSCH.TrBlkSizes(sf_idx+1) > 0)
-                [dec2, data, pdschRx, pdschSymbols2, cws2] = srslte_pdsch(rmccFgOut, rmccFgOut.PDSCH, ... 
-                                                        rmccFgOut.PDSCH.TrBlkSizes(sf_idx+1), ...
-                                                        subframe_rx);
-            else
-                dec2 = 1;
-            end
-             if (~dec2) 
-                fprintf('Error in sf=%d\n',sf_idx);
-            end
-            decoded_srslte(snr_idx) = decoded_srslte(snr_idx)+dec2;
-        end
         
-        if ~isempty(recordedSignal)
+        nErrors_srs(k,rvIndex) = nErrors_srs(k,rvIndex)+~okSRSLTE;          
-            recordedSignal = recordedSignal(flen*10+1:end);
-        end
     end
-    fprintf('SNR: %.1f. Decoded: %d-%d\n',SNRdB, decoded(snr_idx), decoded_srslte(snr_idx))
+    fprintf('SNR=%.1f dB, BLER_mat=%f, BLER_srs=%f\n',SNR(k),nErrors_mat(k,rvIndex)/Nblocks, nErrors_srs(k,rvIndex)/Nblocks);    
 end
 
-if (length(SNR_values)>1)
+PDSCHBLER_MAT = nErrors_mat./Nblocks;
-    semilogy(SNR_values,1-decoded/Npackets/(Nsf),'bo-',...
+PDSCHBLER_MAT(PDSCHBLER_MAT==0)=10^-10;
-             SNR_values,1-decoded_srslte/Npackets/(Nsf), 'ro-')
+
-    grid on;
+PDSCHBLER_SRS = nErrors_srs./Nblocks;
-    legend('Matlab','srsLTE')
+PDSCHBLER_SRS(PDSCHBLER_SRS==0)=10^-10;
-    xlabel('SNR (dB)')
+
-    ylabel('BLER')
+if (Nblocks == 1 && length(SNR) == 1)
-    axis([min(SNR_values) max(SNR_values) 1/Npackets/(Nsf+1) 1])
 else
-    fprintf('Matlab: %d OK\nsrsLTE: %d OK\n',decoded, decoded_srslte);
+    semilogy(SNR,PDSCHBLER_MAT,SNR,PDSCHBLER_SRS)
+    grid on
+    xlabel('Eb/No (dB)')
+    ylabel('BLER')
+    leg=[];
+    for rvIndex = 1:length(rvValues)
+        leg=strvcat(leg,sprintf('Matlab rv=%d',rvValues(rvIndex)));
+    end
+    for rvIndex = 1:length(rvValues)
+        leg=strvcat(leg,sprintf('srsLTE rv=%d',rvValues(rvIndex)));
+    end
+    legend(leg);
+    axis([min(SNR) max(SNR) 10^-4 1])
 end
-

matlab/tests/pdsch_check_rm_files.m

@@ -1,22 +0,0 @@
-nof_cb=11;
-TBS=61664;
-K=5632; % Only supporting 1 K for now
-rv=0;
-chs.Modulation='64QAM';
-chs.NLayers=1;
-% cws must be a vector of size TBS in workspace containing the output of the
-% descrambler
-rmout_mat=lteRateRecoverTurbo(cws{1},TBS,rv,chs);
-scale=700;
-%path='../../build/srslte/lib/phch/test';
-path='.';
-error=zeros(nof_cb,3*K+12);
-rmout_lib=zeros(nof_cb,3*K+12);
-for i=0:nof_cb-1   
-    filename=sprintf('%s/rmout_%d.dat',path,i);
-    x=read_int16(filename);
-    rmout_lib(i+1,:) = reshape(reshape(x,3,[])',[],1); 
-    error(i+1,:)=abs(transpose(rmout_mat{i+1})-rmout_lib(i+1,:)/scale);
-end
-
-plot(reshape(error',1,[]))

matlab/tests/pdsch_decode_test.m

@@ -1,63 +0,0 @@
-enb=struct('NCellID',16,'NDLRB',6,'NSubframe',5,'CFI',3,'CyclicPrefix','Normal','CellRefP',1,'Ng','One','PHICHDuration','Normal','DuplexMode','FDD');
-
-RNTI=65535;
-
-addpath('../../build/srslte/lib/phch/test')
-
-cec.PilotAverage = 'UserDefined';     % Type of pilot averaging
-cec.FreqWindow = 9;                   % Frequency window size    
-cec.TimeWindow = 9;                   % Time window size    
-cec.InterpType = 'cubic';             % 2D interpolation type
-cec.InterpWindow = 'Centered';        % Interpolation window type
-cec.InterpWinSize = 1;                % Interpolation window size  
-
-subframe_rx=lteOFDMDemodulate(enb,inputSignal);
-[hest,nest] = lteDLChannelEstimate(enb, cec, subframe_rx);    
-    
-% Search PDCCH
-pdcchIndices = ltePDCCHIndices(enb); 
-[pdcchRx, pdcchHest] = lteExtractResources(pdcchIndices, subframe_rx, hest);
-[dciBits, pdcchSymbols] = ltePDCCHDecode(enb, pdcchRx, pdcchHest, nest);
-pdcch = struct('RNTI', RNTI);  
-dci = ltePDCCHSearch(enb, pdcch, dciBits); % Search PDCCH for DCI                
-
-if ~isempty(dci)
-        
-    dci = dci{1};
-    disp(dci);
-    
-    % Get the PDSCH configuration from the DCI
-    [pdsch, trblklen] = hPDSCHConfiguration(enb, dci, pdcch.RNTI);
-    pdsch.NTurboDecIts = 5;
-    fprintf('PDSCH settings after DCI decoding:\n');
-    disp(pdsch);
-
-    fprintf('Decoding PDSCH...\n\n');        
-    % Get PDSCH indices
-    [pdschIndices,pdschIndicesInfo] = ltePDSCHIndices(enb, pdsch, pdsch.PRBSet);
-    [pdschRx, pdschHest] = lteExtractResources(pdschIndices, subframe_rx, hest);
-    % Decode PDSCH 
-    [dlschBits,pdschSymbols] = ltePDSCHDecode(enb, pdsch, pdschRx, pdschHest, nest);
-    [sib1, crc] = lteDLSCHDecode(enb, pdsch, trblklen, dlschBits);
-
-    [dec2, data, pdschRx2, pdschSymbols2, e_bits, indices] = srslte_pdsch(enb, pdsch, ... 
-                                                        trblklen, ...
-                                                        subframe_rx);
-
-    
-    scatter(real(pdschSymbols{1}),imag(pdschSymbols{1}))
-
-    if crc == 0
-        fprintf('PDSCH OK.\n\n');
-    else
-        fprintf('PDSCH ERROR.\n\n');
-    end
-        
-    else
-        % indicate that DCI decoding failed 
-        fprintf('DCI decoding failed.\n\n');
-end
-
-indices=indices+1;
-plot(t,indices(t),t,pdschIndices(t))
-    

mex/include/srslte/mex/mexutils.h

@@ -43,6 +43,12 @@
 
 SRSLTE_API bool mexutils_isScalar(const mxArray *ptr);
 
+SRSLTE_API bool mexutils_isCell(const mxArray *ptr);
+
+SRSLTE_API int mexutils_getLength(const mxArray *ptr); 
+
+SRSLTE_API mxArray* mexutils_getCellArray(const mxArray *ptr, int idx);
+
 SRSLTE_API int mexutils_read_cell(const mxArray *ptr, 
                                   srslte_cell_t *cell);
 

mex/lib/mexutils.c

@@ -35,6 +35,20 @@ bool mexutils_isScalar(const mxArray *ptr) {
   return mxGetM(ptr) == 1 && mxGetN(ptr) == 1;
 }
 
+bool mexutils_isCell(const mxArray *ptr) {
+  return mxIsCell(ptr);
+}
+
+int mexutils_getLength(const mxArray *ptr) {
+  const mwSize *dims;
+  dims = mxGetDimensions(ptr);
+  return dims[0];
+}
+
+mxArray* mexutils_getCellArray(const mxArray *ptr, int idx) {
+  return mxGetCell(ptr, idx);
+}
+
 char *mexutils_get_char_struct(const mxArray *ptr, const char *field_name) {
   mxArray *p; 
   p = mxGetField(ptr, 0, field_name);
@@ -98,6 +112,8 @@ int mexutils_read_cf(const mxArray *ptr, cf_t **buffer) {
       __real__ tmp[i] = (float) inr[i]; 
       if (ini) {
         __imag__ tmp[i] = (float) ini[i];
+      } else {
+        __imag__ tmp[i] = 0; 
       }
     }    
     *buffer = tmp; 

srslte/lib/phch/src/dci.c

@@ -650,6 +650,25 @@ int dci_format1As_unpack(srslte_dci_msg_t *msg, srslte_ra_dl_dci_t *data, uint32
     return SRSLTE_ERROR;
   }
   
+  // Check if RA procedure by PDCCH order
+  if (*y == 0) {
+    int nof_bits = riv_nbits(nof_prb);
+    int i=0;
+    while(i<nof_bits && y[1+i] == 1)
+      i++;
+    if (i == nof_bits) {
+      printf("Warning check me: could this be a RA PDCCH order??\n");
+      i=1+10+nof_bits;
+      while(i<msg->nof_bits-1 && y[i] == 0) {
+        i++;
+      }
+      if (i == msg->nof_bits-1) {
+        printf("Received a Format1A RA PDCCH order. Not implemented!\n");
+        return SRSLTE_ERROR;
+      }
+    }
+  }
+
   data->alloc_type = SRSLTE_RA_ALLOC_TYPE2;
   data->type2_alloc.mode = *y++;
 

srslte/lib/phch/src/pdsch.c

@@ -426,6 +426,14 @@ int srslte_pdsch_decode_rnti(srslte_pdsch_t *q,
     */
     srslte_demod_soft_demodulate_s(cfg->grant.mcs.mod, q->d, q->e, cfg->nbits.nof_re);
     
+    /*
+    printf("WARNING REMOVE ME!\n");
+    int16_t *e=q->e;
+    for (int i=0;i<cfg->nbits.nof_bits;i++) {
+      e[i] = e[i]>0?10:-10;
+    }
+    */
+
     /* descramble */
     if (rnti != q->rnti) {
       srslte_sequence_t seq; 

srslte/lib/phch/src/sch.c

@@ -229,13 +229,6 @@ static int encode_tb_off(srslte_sch_t *q,
       parity[0] = (par&(0xff<<16))>>16;
       parity[1] = (par&(0xff<<8))>>8;
       parity[2] = par&0xff;
-
-      if (SRSLTE_VERBOSE_ISDEBUG()) {
-        DEBUG("DATA: ", 0);
-        srslte_vec_fprint_byte(stdout, data, cb_segm->tbs/8);
-        DEBUG("PARITY: ", 0);
-        srslte_vec_fprint_byte(stdout, parity, 3);
-      }      
     }
     
     wp = 0;
@@ -425,7 +418,7 @@ static int decode_tb(srslte_sch_t *q,
 
         srslte_tdec_decision_byte(&q->decoder, q->cb_in, cb_len);
                  
-        /* Check Codeblock CRC and stop early if incorrect */
+        /* Check Codeblock CRC and stop early if correct */
         if (!srslte_crc_checksum_byte(crc_ptr, q->cb_in, len_crc)) {
           early_stop = true;           
         }
@@ -448,6 +441,10 @@ static int decode_tb(srslte_sch_t *q,
         memcpy(parity, &q->cb_in[(rlen - 24)/8], 3 * sizeof(uint8_t));
       }
       
+      if (SRSLTE_VERBOSE_ISDEBUG()) {
+        early_stop = true; 
+      }
+      
       /* Set read/write pointers */
       wp += rlen;
       rp += n_e;

srslte/lib/phch/test/pdsch_test_mex.c

@@ -45,6 +45,8 @@ void help()
 
 extern int indices[2048];
 
+int rv_seq[4] = {0, 2, 3, 1};
+
 /* the gateway function */
 void mexFunction(int nlhs, mxArray *plhs[], int nrhs, const mxArray *prhs[])
 {
@@ -63,7 +65,7 @@ void mexFunction(int nlhs, mxArray *plhs[], int nrhs, const mxArray *prhs[])
     return;
   }
 
-  srslte_verbose = SRSLTE_VERBOSE_INFO;
+  srslte_verbose = SRSLTE_VERBOSE_DEBUG;
   bzero(&cfg, sizeof(srslte_pdsch_cfg_t));
 
   if (mexutils_read_cell(ENBCFG, &cell)) {
@@ -174,9 +176,9 @@ void mexFunction(int nlhs, mxArray *plhs[], int nrhs, const mxArray *prhs[])
   }
       
   /** Allocate input buffers */
-  if (mexutils_read_cf(INPUT, &input_fft) < 0) {
+  int nof_retx=1; 
-    mexErrMsgTxt("Error reading input signal\n");
+  if (mexutils_isCell(INPUT)) {
-    return; 
+    nof_retx = mexutils_getLength(INPUT);
   } 
   
   cf_t *ce[SRSLTE_MAX_PORTS];
@@ -184,39 +186,55 @@ void mexFunction(int nlhs, mxArray *plhs[], int nrhs, const mxArray *prhs[])
     ce[i] = srslte_vec_malloc(SRSLTE_SF_LEN_RE(cell.nof_prb, cell.cp) * sizeof(cf_t));
   }
 
-  if (nrhs > NOF_INPUTS) {
-    cf_t *cearray = NULL; 
-    int nof_re = mexutils_read_cf(prhs[NOF_INPUTS], &cearray);
-    cf_t *cearray_ptr = cearray; 
-    for (i=0;i<cell.nof_ports;i++) {
-      for (int j=0;j<nof_re/cell.nof_ports;j++) {
-        ce[i][j] = *cearray;
-        cearray++;
-      }
-    }    
-    if (cearray_ptr)
-      free(cearray_ptr);
-  } else {
-    srslte_chest_dl_estimate(&chest, input_fft, ce, cfg.sf_idx);    
-  }
-  
-  float noise_power;
-  if (nrhs > NOF_INPUTS + 1) {
-    noise_power = mxGetScalar(prhs[NOF_INPUTS+1]);
-  } else {
-    noise_power = srslte_chest_dl_get_noise_estimate(&chest);
-  }
-  
   uint8_t *data_bytes = srslte_vec_malloc(sizeof(uint8_t) * grant.mcs.tbs/8);
   if (!data_bytes) {
     return;
   }
-  
   srslte_sch_set_max_noi(&pdsch.dl_sch, max_iterations);
 
-  int r = srslte_pdsch_decode(&pdsch, &cfg, &softbuffer, input_fft, ce, noise_power, data_bytes);
+  int r=-1;
+  for (int rvIdx=0;rvIdx<nof_retx && r != 0;rvIdx++) {
     
-  free(data_bytes);
+    mxArray *tmp = (mxArray*) INPUT; 
+    if (mexutils_isCell(INPUT)) {
+      tmp = mexutils_getCellArray(INPUT, rvIdx);
+      if (nof_retx > 1) {
+        cfg.rv = rv_seq[rvIdx%4];
+      }
+    } 
+    if (mexutils_read_cf(tmp, &input_fft) < 0) {
+      mexErrMsgTxt("Error reading input signal\n");
+      return; 
+    }
+    
+    if (nrhs > NOF_INPUTS) {
+      cf_t *cearray = NULL; 
+      int nof_re = mexutils_read_cf(prhs[NOF_INPUTS], &cearray);
+      cf_t *cearray_ptr = cearray; 
+      for (i=0;i<cell.nof_ports;i++) {
+        for (int j=0;j<nof_re/cell.nof_ports;j++) {
+          ce[i][j] = *cearray;
+          cearray++;
+        }
+      }    
+      if (cearray_ptr)
+        free(cearray_ptr);
+    } else {
+      srslte_chest_dl_estimate(&chest, input_fft, ce, cfg.sf_idx);    
+    }
+    
+    float noise_power;
+    if (nrhs > NOF_INPUTS + 1) {
+      noise_power = mxGetScalar(prhs[NOF_INPUTS+1]);
+    } else {
+      noise_power = srslte_chest_dl_get_noise_estimate(&chest);
+    }
+
+    r = srslte_pdsch_decode(&pdsch, &cfg, &softbuffer, input_fft, ce, noise_power, data_bytes);
+
+    free(input_fft);
+
+  }
   
   uint8_t *data = malloc(grant.mcs.tbs);
   srslte_bit_unpack_vector(data_bytes, data, grant.mcs.tbs);
@@ -237,14 +255,15 @@ void mexFunction(int nlhs, mxArray *plhs[], int nrhs, const mxArray *prhs[])
     mexutils_write_s(pdsch.e, &plhs[4], cfg.nbits.nof_bits, 1);  
   }
   
+  srslte_softbuffer_rx_free(&softbuffer);
   srslte_chest_dl_free(&chest);
   srslte_pdsch_free(&pdsch);
   
   for (i=0;i<cell.nof_ports;i++) {
     free(ce[i]);
   }
+  free(data_bytes);
   free(data);
-  free(input_fft);
   
   return;
 }