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lteMIB

MIB encoding and decoding

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Syntax

mib = lteMIB(enb)
enb = lteMIB(mib)
enb = lteMIB(mib,enb)

Description

mib = lteMIB(enb) allows encoding and decoding of the MIB broadcast control channel (BCCH) message from cell-wide settings.

It creates the 24-bit-long MIB message, mib, from the fields of cell-wide settings structure, enb. See TS 36.331 [1], Sections 5.2.1.1 and 6.2.2 for further description of the MIB.

enb = lteMIB(mib) performs the inverse processing of the preceding syntax, taking as input the MIB message bits, mib, and creating the cell-wide settings structure, enb.

example

enb = lteMIB(mib,enb) includes in the enb output structure any fields contained in the enb input structure. For any of the fields already present in the input structure, the value decoded from the MIB replaces the existing value.

Note

Within the MIB, the system frame number (SFN) is stored as floor(SFN/4). Therefore, when enb is created from an MIB bit sequence, enb.NFrame satisfies mod(enb.NFrame,4)==0 and the frame number modulo 4 must be established by other means. For example, this can be done by using the nfmod4 output of ltePBCHDecode.

Examples

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Open Live Script

Create a column vector of MIB message bits.

mib = [0,1,0,0,1,0,1,1,0,0,1,1,1,1,0,0,0,0,0,0,0,0,0,0].';

Decode MIB message bits.

enb = lteMIB(mib)
enb = struct with fields:
            NDLRB: 25
    PHICHDuration: 'Normal'
               Ng: 'One'
           NFrame: 828

Input Arguments

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Cell-wide settings, specified as a structure. enb can contain the following fields.

Number of downlink resource blocks, specified as a positive integer scalar value. NDLRB must be between 6 and 110.

Note

If NDLRB is a nonstandard bandwidth, not one of the set {6,15,25,50,75,100}, all ones are inserted into the first 3 bits, the dl-Bandwidth bit field, of the MIB message, mib.

Data Types: double

HICH group multiplier, specified as 'Sixth', 'Half', 'One', or 'Two'.

Data Types: char | string

Frame number, specified as a nonnegative scalar integer.

Data Types: double

PHICH duration, specified as 'Normal' or 'Extended'.

Data Types: char | string

Data Types: struct

MIB message bit sequence, specified as a 24-bit column vector.

Note

If the first 3 bits, the dl-Bandwidth bit field, of the MIB message do not contain the equivalent of a decimal between 0 and 5 (MSB first, corresponding to the RB set {6,15,25,50,75,100}), the returned NDLRB is 0.

Data Types: double | int8 | logical

Output Arguments

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MIB message, returned as a 24-bit column vector.

Note

If the enb.NDLRB input parameter field is a nonstandard bandwidth, not one of the set {6,15,25,50,75,100}, the first 3 bits of mib, the dl-Bandwidth bit field, are all ones.

Data Types: int8

Cell-wide settings created from MIB, returned as a structure. enb contains the following fields.

Number of downlink resource blocks, returned as a nonnegative scalar integer.

Note

If the first 3 bits, the dl-Bandwidth bit field, of the input MIB message, mib, do not contain the equivalent of a decimal between 0 and 5 (MSB first, corresponding to the RB set {6,15,25,50,75,100}), NDLRB is 0. The MIB message should have 24 bits. Longer messages are truncated to 24 elements, while shorter messages are zero padded.

Data Types: int32

PHICH duration, returned as 'Normal' or 'Extended'.

Data Types: char

HICH group multiplier, specified as 'Sixth', 'Half', 'One', or 'Two'.

Data Types: char

Frame number, specified as a scalar value.

Data Types: int32

Data Types: struct

References

[1] 3GPP TS 36.331. “Evolved Universal Terrestrial Radio Access (E-UTRA); Radio Resource Control (RRC); Protocol specification.” 3rd Generation Partnership Project; Technical Specification Group Radio Access Network. URL: https://www.3gpp.org.

Version History

Introduced in R2014a

See Also

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