lteNPDCCHIndices

Generate NPDCCH RE indices

Syntax

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

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

Description

[ind,info] = lteNPDCCHIndices(enb,chs) returns ind, a matrix containing narrowband physical downlink control channel (NPDCCH) resource element (RE) indices, and info, a structure containing information related to the indices. You can use ind to index elements of the subframe resource grid directly for all antenna ports in accordance with 3GPP TS 36.211 Section 10.2.5.5 of [1]. Initialize this function with cell-wide settings enb and channel transmission configuration chs.

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

Examples

Generate NPDCCH RE Indices and Info Structure

Generate the NPDCCH RE indices mapping and display related information.

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

enb.NNCellID = 10;
enb.NBRefP = 1;

Create the channel transmission configuration. Specify the value of narrowband control channel element (NCCE).

chs.NCCE = 0; % NPDCCH Format 0

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

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

ans = 7×1

     1
     2
     3
     4
     5
     6
    13

Display the fields contained in the info structure.

info.G

ans = 160

info.Gd

ans = 80

Generate NPDCCH RE Indices

Generate the NPDCCH 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;

Create the channel transmission configuration.

chs.NCCE = [0 1]; % NPDCCH Format 1

Generate the NPDCCH RE indices matrix. Display the first seven indices.

ind = lteNPDCCHIndices(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 — Cell-wide settings

structure

Cell-wide settings, specified as a structure containing these fields.

Name	Required or Optional	Values	Description	Dependencies	Data Types
NNCellID	Required	Nonnegative integer	Narrowband physical layer cell identity	—	double
NBRefP	Required	1, 2	Number of narrowband reference signal (NRS) antenna ports	—	double
OperationMode	Optional	'Standalone' (default), 'Inband-SamePCI', 'Inband-DifferentPCI', 'Guardband'	NB-IoT operation mode, specified as one of these values: 'Standalone' – NB-IoT standalone operation within any 180-kHz band outside any LTE carrier bandwidth 'Inband-SamePCI' – NB-IoT in-band operation with the same PCI as an LTE carrier 'Inband-DifferentPCI' – NB-IoT in-band operation with a different PCI to an LTE carrier 'Guardband' – NB-IoT guard-band operation utilizing unused resource blocks within the guard-band of an LTE carrier	—	char, string
CellRefP	Optional	1, 2, 4	Number of cell-specific reference signal (CRS) antenna ports. The value of this field must be either the value to which you set the NBRefP field (default) or 4.	This field applies only when you specify the OperationMode field as 'Inband-SamePCI' or 'Inband-DifferentPCI'. When you specify the OperationMode field as 'Inband-SamePCI', the lteNPDCCHIndices function sets this field to the value of the NBRefP field.	double
ControlRegionSize	See Dependencies column	3 (default), scalar in the interval [0, 13]	LTE control region size. This field sets the starting OFDM symbol index (zero-based) in a subframe.	Required when you specify the OperationMode field as 'Inband-SamePCI' or 'Inband-DifferentPCI'. The lteNPDCCHIndices function sets this field to 0 when you specify the OperationMode field as 'Standalone' or 'Guardband'.	double

Data Types: struct

chs — Channel transmission configuration

structure

Channel transmission configuration, specified as a structure containing this field.

Name	Required or Optional	Values	Description	Data Types
NCCE	Required	0, 1	Narrow band control channel element (NCCE) corresponds to six consecutive subcarriers in a subframe. NCCE 0 occupies subcarriers from 0 to 5 and NCCE 1 occupies subcarriers from 6 to 11. Aggregation of 1 or 2 NCCE is used to transmit NPDCCH in two formats: Format 0 - has one NCCE and the value is either 0 or 1. Format 1 - has two NCCE and the value is [0 1].	double

Data Types: struct

opts — Output format and index base of generated indices

character vector | cell array of character vectors | string array

Output format and index base of generated indices, specified as a character vector, a cell array of character vectors, or a string array. You can specify these options as a single character vector or string scalar by a space-separated list of values placed inside quotation marks. This field can contain any of these values.

Option	Values	Description
Output format	'ind' (default), 'sub'	Output format of generated indices, specified as 'ind' or 'sub'. The function returns the indices as an NRE-by-NBRefP matrix when you specify 'ind'. NRE is the number of resource elements. The function returns the indices as an NRE-by-3 matrix when you specify 'sub', where each row of the matrix contains the subcarrier, symbol, and antenna port as its first, second, and third entries, respectively.
Index base	'1based' (default), '0based'	Index base, specified as '1based' or '0based'. To generate indices whose first value is 1, specify '1based'. To generate indices whose first value is 0, specify '0based'.

Example: 'ind 0based', "ind 0based", {'ind','0based'}, and ["ind","0based"] specify the same output options.

Data Types: char | string | cell

Output Arguments

ind — NPDCCH RE indices

real-valued matrix

NPDCCH RE indices, returned as an N_RE-by-P real-valued matrix, where N_RE is the number of resource elements and P is the number of resource array planes. Each column of ind contains the per-antenna indices for the N_RE resource elements in each of the P resource array planes.

Data Types: double

info — Information related to NPDCCH indices

structure

Information related to NPDCCH indices, returned as a structure containing these fields.

Name	Values	Description	Data Types
G	scalar	Number of coded and rate-matched downlink control information (DCI) data bits for a codeword.	double
Gd	scalar	Number of coded and rate-matched DCI data symbols per layer.	double

Data Types: struct

References

[1] 3GPP TS 36.211. “Physical channels and modulation.” 3rd Generation Partnership Project; Technical Specification Group Radio Access Network; Evolved Universal Terrestrial Radio Access (E-UTRA). URL: https://www.3gpp.org.