MATLAB Examples

Resource Blocks

The 3GPP documents describes a resource block to be a group of resource elements spanning 12 consecutive subcarriers in the frequency domain and one slot in the time domain. For processing efficiency, the LTE System Toolbox™, operates on a subframe (two timeslot) basis and describes a resource block pair to represent 12 consecutive subcarriers spanning in the frequency domain and one subframe (two slots) in the time domain. For example, the command ltePDSCHIndices uses the parameter PRBSet to define the set of physical resource block (PRB) indices for a subframe of data.

Create the cell-wide settings structure and define the PDSCH configuration.

enb.CellRefP = 4;
enb.CFI = 1;
enb.NCellID = 1;
enb.NSubframe = 0;
enb.NDLRB = 6;
enb.CyclicPrefix = 'Normal';
enb.DuplexMode = 'FDD';

pdsch.TxScheme = 'TxDiversity';
pdsch.Modulation = 'QPSK';
pdsch.RNTI = 1;
pdsch.PRBSet = (0:5).';

Create a set of PDSCH PRB indices for the initialized configuration.

pdschIndices = ltePDSCHIndices(enb,pdsch,pdsch.PRBSet);
size(pdschIndices)
pdschIndices(1:10,:)
pdsch
ans =

   384     4


ans =

  10x4 uint32 matrix

    145   1153   2161   3169
    146   1154   2162   3170
    147   1155   2163   3171
    148   1156   2164   3172
    149   1157   2165   3173
    150   1158   2166   3174
    151   1159   2167   3175
    152   1160   2168   3176
    153   1161   2169   3177
    154   1162   2170   3178


pdsch = 

  struct with fields:

      TxScheme: 'TxDiversity'
    Modulation: 'QPSK'
          RNTI: 1
        PRBSet: [6x1 double]

pdsch.PRBSet can be either a column vector or a two-column matrix. If you provide a column vector, the resource allocation is the same in both slots of the subframe, which means the set of resource indices applies to both subframe time slots. On the other hand, if you provide a two-column matrix, the PRB indices refer to each slot individually.