lteDLResourceGridSize

Size of downlink subframe resource array

Syntax

d = lteDLResourceGridSize(enb)

d = lteDLResourceGridSize(enb,p)

Description

d = lteDLResourceGridSize(enb) returns a three-element row vector of dimension lengths for the resource array generated from the cell-wide settings structure enb. For more information on the resource grid and the multidimensional array used to represent the resource elements for one subframe across all configured antenna ports, see Representing Resource Grids.

d = lteDLResourceGridSize(enb,p) returns a three-element row vector, where p directly specifies the number of antenna planes in the array. In this syntax, CellRefP is not required as a structure field of enb.

Examples

Determine Downlink Subframe Resource Array Size

Determine the size of a downlink subframe resource array.

Determine the dimensions of a downlink subframe resource array, using cell-wide settings, enb. Then, use the returned vector directly to create a resource grid as a multidimensional array.

enb = struct('NDLRB',50,'CellRefP',2,'CyclicPrefix','Normal');
rgrid = zeros(lteDLResourceGridSize(enb));
size(rgrid)

ans = 1×3

   600    14     2

The same result can be obtained by calling the lteDLResourceGrid function.

Get Downlink Subframe Resource Array Size Using Optional Antenna Plane Input

Get the downlink subframe resource array size from an downlink configuration structure using the antenna plane input. Then, use the returned vector to directly create a MATLAB™ array.

cfgdl = struct('NDLRB',50,'CyclicPrefix','Normal');
p = 2;
griddl = zeros(lteDLResourceGridSize(cfgdl,p));
size(griddl)

ans = 1×3

   600    14     2

The output grid, griddl, is a resource array. This resource array size could be obtained in a similar manner using the lteResourceGridSize function.

Input Arguments

enb — Cell-wide settings

structure

Cell-wide settings, specified as a structure having the following fields.

NDLRB — Number of downlink resource blocks

scalar integer from 6 to 110

Number of downlink resource blocks, specified as a scalar integer from 6 to 110. Standard bandwidth values are 6, 15, 25, 50, 75, and 100.

Data Types: double | char

CellRefP — Number of cell-specific reference signal antenna ports

1 | 2 | 4

Number of cell-specific reference signal antenna ports, specified as 1, 2, or 4.

Data Types: double

CyclicPrefix — Cyclic prefix length

'Normal' (default) | optional | 'Extended'

Cyclic prefix length, specified as 'Normal' or 'Extended'.

Data Types: char

Data Types: struct

p — Number of antenna planes

positive scalar integer

Number of antenna planes, specified as a positive scalar integer. This argument directly specifies the number of antenna planes in the array.

Data Types: double

Output Arguments

d — Downlink resource grid dimensions

numeric 1-by-3 row vector

Downlink resource grid dimensions, returned as a numeric 1-by-3 row vector. When the function has a single argument, d is [N M CellRefP]. N is the number of subcarriers (12×NDLRB). M is the number of OFDM symbols in a subframe, 14 for normal cyclic prefix and 12 for extended cyclic prefix. CellRefP is the number of transmit antenna ports. When the number of antenna planes, p, is specified as the second input argument, then d is [N M p] and the input field CellRefP of enb is not required.

Data Types: double