lteNPDSCHIndices

NB-IoT physical downlink resource element indices

Syntax

[ind,info] = lteNPDSCHIndices(enb,chs)

[ind,info] = lteNPDSCHIndices(enb,chs,opts)

Description

[ind,info] = lteNPDSCHIndices(enb,chs) returns a matrix, ind, containing narrowband physical downlink shared channel (NPDSCH) resource element (RE) indices and a structure, info, containing information related to the NPDSCH indices. By default, the output indices are returned in a 1-based, linear indexed 3-D array representing the subframe resource element grid for all antenna ports. You can use ind to index elements of the subframe resource grid directly for all antenna ports. This function is initialized with cell-wide settings, enb, and channel transmission configuration, chs.

[ind,info] = lteNPDSCHIndices(enb,chs,opts) formats the returned indices using options specified by opts.

Examples

Generate NPDSCH RE Indices and Info Structure

Generate the NPDSCH RE indices mapping for one antenna and display related information.

Create the eNodeB structure cell-wide settings for one antenna.

enb.NNCellID = 10;
enb.NBRefP = 1;
enb.OperationMode = 'Inband-SamePCI';

Create the channel transmission configuration. Specify the number of subframes (NSF). The NSF field is required for returning information related to the NPDSCH indices.

chs.NPDSCHDataType = 'BCCHNotSIB1NB';
chs.NSF = 2;

Generate the NPDSCH RE indices column vector. Display the first seven indices.

[ind,info] = lteNPDSCHIndices(enb,chs);
ind(1:7)

ans = 7×1

    37
    38
    39
    40
    41
    42
    43

Display the fields contained in the info structure.

info.G

ans = 472

info.Gd

ans = 236

Generate NPDSCH RE Indices

Generate the NPDSCH RE 0-based indices mapping in linear index form for two antennas.

Create the eNodeB structure cell-wide settings for two antennas.

enb.NNCellID = 10;
enb.NBRefP = 2;
enb.OperationMode = 'Standalone';

Create the channel transmission configuration.

chs.NPDSCHDataType = 'SIB1NB';

Generate the 0-based NPDSCH RE indices in linear index form. The indices matrix has two columns, one for each antenna ports. Display the first seven indices.

ind = lteNPDSCHIndices(enb,chs,{'0based','ind'});
ind(1:7,:)

ans = 7×2

     0   168
     1   169
     2   170
     3   171
     4   172
     5   173
     6   174

Input Arguments

enb — eNodeB cell-wide settings

structure

eNodeB cell-wide settings, specified as a structure containing these parameter fields.

Parameter Field	Required or Optional	Values	Description
NNCellID	Required	Nonnegative integer	Narrowband physical layer cell identity
NBRefP	Required	1, 2	Number of transmit antenna ports for NB-IoT eNodeB
OperationMode	Optional	'Standalone' (default), 'Inband-SamePCI', 'Inband-DifferentPCI', 'Guardband'	NB-IoT operation mode
CellRefP	Optional (See note)	1, 2, 4	Number of cell-specific reference signal (CRS) antenna ports
ControlRegionSize	Optional (See note)	3 (default), scalar from 0 to 13	LTE control region size, used to set the starting OFDM symbol index (0-based) in a subframe
Note CellRefP When OperationMode is 'Guardband' or 'Standalone', then CellRefP is ignored. When OperationMode is 'Inband-SamePCI', then CellRefP is equal to NBRefP. ControlRegionSize When OperationMode is 'Inband-SamePCI' or 'Inband-DifferentPCI', and chs.NPDSCHDataType is not equal to 'SIB1NB', then ControlRegionSize is required. When OperationMode is 'Inband-SamePCI' or 'Inband-DifferentPCI', and chs.NPDSCHDataType is 'SIB1NB', then ControlRegionSize is set to 3. When OperationMode is 'Guardband' or 'Standalone', then ControlRegionSize is set to 0.

Data Types: struct

chs — NPDSCH-specific channel transmission configuration

structure

NPDSCH-specific channel transmission configuration, specified as a structure that can contain the following parameter fields.

Parameter Field	Required or Optional	Values	Description
NPDSCHDataType	Optional	'NotBCCH' (default), 'SIB1NB', 'BCCHNotSIB1NB'	Type of the data carried by NPDSCH
NSF	Optional (See note)	Nonnegative integer	Number of subframes that a codeword is mapped to (not including repetitions)
Note If you return the second output parameter info, and NPDSCHDataType is not equal to 'SIB1NB', then NSF is required. If you return info and NPDSCHDataType is 'SIB1NB', then NSF is set to 8. If you do not return info, then NSF is ignored.

Data Types: struct

opts — Index generation options

character vector | cell array of character vectors | string array

Index generation options, specified as a character vector, cell array of character vectors, or string array. For convenience, you can specify several options as a single character vector or string scalar by a space-separated list of values placed inside the quotes. Values for opts when specified as a character vector include (use double quotes for string):

Option	Values	Description
Indexing style	'ind' (default), 'sub'	Style for the returned indices, specified as one of the following options. 'ind' — Return the indices in linear index form as a column vector. 'sub' — Return the indices in [subcarrier, symbol, port] subscript row style. The number of rows in the output, ind, is the number of resource elements (NRE). Thus, ind is an NRE-by-3 matrix.
Index base	'1based' (default), '0based'	Base value of the returned indices. Specify '1based' to generate indices where the first value is 1. Specify '0based' to generate indices where the first value is 0.

Example: 'ind 1based', "ind 1based", {'ind','1based'}, or ["ind","1based"] specify the same formatting options.

Data Types: char | string | cell

Output Arguments

ind — NPDSCH RE indices

N_RE-by-P matrix

NPDSCH RE indices, returned as a N_RE-by-P matrix. Each column of the matrix contains the per-antenna indices for the N_RE resource elements in each of the P resource array planes.

info — Information related to NPDSCH indices

structure

Information related to NPDSCH indices, returned as a structure containing the following fields.

Parameter Field	Values	Description
G	one- or two-element vector	Number of coded and rate-matched DL-SCH data bits for each codeword
Gd	Integer equal to CHS.NSF multiplied by the number of rows in the NPDSCH indices	Number of coded and rate-matched DL-SCH data symbols per layer

Data Types: uint32