Documentation

ltePHICHInfo

PHICH resource information

Syntax

Description

example

info = ltePHICHInfo(enb) returns a structure, info, containing information about the physical hybrid ARQ indicator channel (PHICH) subframe resources.

Examples

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Get PHICH Resource Information

This example shows that in a normal cyclic prefix system subframe, with 50 DL resource blocks and HICH group multiplier set to 'Sixth' there are 16 PHICH available, split between two PHICH groups of 8 sequences.

Initialize the cell-wide configuration structure, enb

enb.NDLRB = 50;
enb.Ng = 'Sixth';

Display the PHICH information

info = ltePHICHInfo(enb)
Warning: Using default value for parameter field CyclicPrefix (Normal) 
Warning: Using default value for parameter field DuplexMode (FDD) 
Warning: Using default value for parameter field PHICHDuration (Normal) 

info = 

             NREG: 6
              NRE: 24
           NPHICH: 16
          NGroups: 2
    NMappingUnits: 2
       NSequences: 8
    PHICHDuration: 1

Note: The warning messages generated simply advise you that default values are available and being used for uninitialized parameters. To suppress warnings for defaulted lte parameter settings precede code with the command "lteWarning('off','DefaultValue')".

Get PHICH Resource Information from RMC

This example shows that for RMC R.14, there are 16 PHICH available, split between two PHICH groups of 8 sequences.

Initialize the cell-wide configuration structure, enb, using RMC R.14

rc = 'R.14';
enb = lteRMCDL(rc);

Display the PHICH information

info = ltePHICHInfo(enb)
info = 

             NREG: 6
              NRE: 24
           NPHICH: 16
          NGroups: 2
    NMappingUnits: 2
       NSequences: 8
    PHICHDuration: 1

Input Arguments

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enb — eNodeB cell-wide settingsscalar structure

eNodeB cell-wide settings structure that can contain these parameter fields.

Parameter FieldRequired or OptionalValuesDescription
NDLRBRequired

Scalar integer (6, ..., 110). Standard bandwidth values are 6, 15, 25, 50, 75, and 100. NDLRB will also accept the standardized bandwidths in string format from the set {'1.4MHz', '3MHz', ‘5MHz', '10MHz', ‘15MHz', ‘20MHz'}.

Number of downlink (DL) resource blocks (RBs)

CyclicPrefixOptional

'Normal' (default), 'Extended'

Cyclic prefix length

NgRequired

'Sixth', 'Half', 'One', 'Two'

HICH group multiplier

PHICHDurationOptional

Nonnegative scalar integer

PHICH duration

DuplexModeOptional

'FDD' (default), 'TDD'

Duplexing mode, specified as:

  • 'FDD' for Frequency Division Duplex or

  • 'TDD' for Time Division Duplex

The following parameters are dependent upon the condition that DuplexMode is set to 'TDD'.
  TDDConfigOptional

0 (default), 1, 2, 3, 4, 5, 6

Uplink or downlink configuration

  NSubframeRequired

Nonnegative scalar integer

Subframe number

Output Arguments

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info — PHICH subframe resource informationscalar structure

PHICH subframe resource information, returned as a scalar structure. info contains the following fields.

Parameter FieldDescriptionValuesData Type
NRE

Number of resource elements (REs) assigned to all PHICH

Nonnegative scalar integer

uint64
NREG

Number of resource element groups assigned to all PHICH

Nonnegative scalar integer

uint64
NPHICH

Number of individual PHICH available

Nonnegative scalar integer

uint64
NGroups

Number of PHICH groups

Nonnegative scalar integer

int8
NMappingUnits

Number of PHICH mapping units

Nonnegative scalar integer

int8
NSequences

Number of orthogonal sequences in each PHICH group

Nonnegative scalar integer

int8
PHICHDuration

PHICH duration

Nonnegative scalar integer

int8

The control region of a subframe can contain up to NPHICH separate PHICHs with each carrying a single hybrid ARQ ACK or NACK. Multiple PHICHs can be mapped to the same set of resource elements through PHICH groups. Each PHICH in a group is carried on one of NSequences orthogonal sequences. For mapping to resources, the groups are combined into mapping units where each unit spans three resource element groups. Thus, NREG is 3×NMappingUnits and NRE is 4×3×NMappingUnits. The Ng parameter controls the number of groups available for a given bandwidth.

Introduced in R2014a

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