dvbsLDPCPCM

Generate parity-check matrix for DVB-S2/S2X LDPC codes

Since R2024b

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    Syntax

    H = dvbsLDPCPCM(r)
    H = dvbsLDPCPCM(r,frameType)
    H = dvbsLDPCPCM(r,frameType,outputFormat)

    Description

    H = dvbsLDPCPCM(r) returns a parity-check matrix, H, of the low-density parity-check (LDPC) code with code rate r from the Digital Video Broadcasting Satellite Second Generation (DVB-S2) or Digital Video Broadcasting Satellite Second Generation extended (DVB-S2X) standard.

    example

    H = dvbsLDPCPCM(r,frameType) specifies the DVB-S2/S2X frame type.

    H = dvbsLDPCPCM(r,frameType,outputFormat) specifies the format for the output parity-check matrix.

    Examples

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    Open Live Script

    Create a parity-check matrix for a 2/3 code rate DVB-S2 LDPC code.

    pcmatrix = dvbsLDPCPCM("2/3");

    Configure the Communications Toolbox™ LDPC encoder using the parity-check matrix.

    cfgLDPCEnc = ldpcEncoderConfig(pcmatrix);

    Generate random information bits as a binary column vector, where the number of bits matches the number of information bits for the encoder configuration.

    infoBits = rand(cfgLDPCEnc.NumInformationBits,1) < 0.5;

    Produce the codeword by encoding the information bits using the LDPC encoder configuration.

    codeword = ldpcEncode(infoBits,cfgLDPCEnc);

    Input Arguments

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    DVB-S2/S2X LDPC code rate, specified as one of these options.

    • Applicable for DVB-S2 — "1/4", "1/3", "2/5", "1/2", "3/5", "2/3", "3/4", "4/5", "5/6", "8/9", or "9/10".

    • Applicable for DVB-S2X — In addition to the code rates applicable for DVB-S2, DVB-S2X also supports these code rates.

      "2/9", "13/45", "9/20", "90/180", "96/180", "11/20", "100/180", "104/180", "26/45", "18/30", "28/45", "23/36", "116/180", "20/30", "124/180", "25/36", "128/180", "13/18", "132/180", "22/30", "135/180", "140/180", "7/9", "154/180", "1/5", "11/45", "4/15", "14/45", "7/15", "8/15", and "32/45".

    Data Types: char | string

    DVB-S2/S2X frame type, specified as one of these values.

    • "normal" — Sets the LDPC code block length to 64,800 bits.

    • "medium" — Sets the LDPC code block length to 32,400 bits.

    • "short" — Sets the LDPC code block length to 16,200 bits.

    If frameType is not specified for an input code rate, the function sets it as the next largest available frame type.

    To determine the frame types supported for a specified code rate, see Tips.

    Data Types: char | string

    Output format for parity-check matrix H, specified as one of these two values.

    • "sparse" — The function returns H as a sparse logical matrix.

    • "indices" — The function returns H as a two-column, double-precision matrix that defines the row and column indices of the 1s in H.

    Data Types: char | string

    Output Arguments

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    Parity-check matrix, returned as a matrix.

    Data Types: double | logical

    Tips

    The table indicates the valid frameType values for each input code rate r.

    Code RateFrame TypeReference Standard
    1/4normal, shortDVB-S2/S2X
    1/3normal, short
    mediumDVB-S2X
    1/4normal, shortDVB-S2/S2X
    2/5
    1/2
    3/5
    2/3
    3/4
    4/5
    5/6
    8/9
    9/10normal
    2/9DVB-S2X
    13/45
    9/20
    90/180
    96/180
    11/20
    100/180
    104/180
    26/45normal, short
    18/30normal
    28/45
    23/36
    116/180
    20/30
    124/180
    25/36
    128/180
    13/18
    132/180
    22/30
    135/180
    140/180
    7/9
    154/180
    11/45short, medium
    4/15short
    14/45
    7/15
    8/15
    32/45
    1/5medium

    References

    [1] ETSI Standard EN 302 307-1 V1.4.1 (2014-11). Digital Video Broadcasting (DVB); Second Generation Framing Structure, Channel Coding and Modulation Systems for Broadcasting, Interactive Services, News Gathering and other Broadband Satellite Applications (DVB-S2).

    [2] ETSI Standard EN 302 307-2 V1.1.1(2015-11). Digital Video Broadcasting (DVB); Second Generation Framing Structure, Channel Coding and Modulation Systems for Broadcasting, Interactive Services, News Gathering and other Broadband Satellite Applications; Part 2: DVB-S2 Extensions (DVB-S2X).

    Extended Capabilities

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    Version History

    Introduced in R2024b

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    See Also

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