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WCDMA3G_TFCIEncoder


Description: TFCI encoder
Library: 3GPPFDD 10-99, Channel Coding
Class: SDFWCDMA3G_TFCIEncoder

Parameters

Name

Description

Default

Type

Range

LinkDir

link direction: Downlink, Uplink

Downlink

enum

 

TFCIBitsNum

number of TFCI bits

6

int

[1, 10]

DPCHType

dedicated physical channel type: DPCH_15_kbps, DPCH_30_kbps, DPCH_60_kbps, DPCH_120_kbps, DPCH_240_kbps, DPCH_480_kbps, DPCH_960_kbps, DPCH_1920_kbps

DPCH_15_kbps

enum

 

Pin Inputs

Pin

Name

Description

Signal Type

1

TFCI

input TFCI information

int

Pin Outputs

Pin

Name

Description

Signal Type

2

TFCIOut

encoded TFCI information

int

Notes/Equations
  1. This model is used to implement transport format combination indicator (TFCI) coding. The TFCI encoder uses a (30,10) punctured sub-code of the second-order Reed-Muller code for the input TFCI information, as illustrated in the following figure.
    Each firing, 30 or 120 (depending on DCHType) TFCIOut tokens are produced when one TFCI token is consumed. The default value for TFCIBitsNum is 6; the default for DCHType is DPCH_15_kbps. The value of TFCI token should be in the range of [0, 2TFCIBitsNum - 1].

    TFCI Encoder
  2. Model functions
    TFCI information is read from the input buffer.
    TFCI information is encoded by the (32,10) sub-code of second-order Reed-Muller code. The code words of the (32,10) sub-code of second-order Reed-Muller code are linear combination of 10 basis sequences: all 1s; 5 OVSF codes (C32,1, C32,2, C32,4, C32,8, C32,16); and, 4 masks (Mask1, Mask2, Mask3, Mask4). The four mask sequences are:

    Mask1: 00101000011000111111000001110111
    Mask2: 00000001110011010110110111000111
    Mask3: 00001010111110010001101100101011
    Mask4: 00011100001101110010111101010001

    For information bits a0, a1, a2, a3, a4, a5, a6, a7, a8, a9 (a0=LSB and a9=MSB), the encoder structure is shown in the following figure.
    Code words of the (32,10) sub-code of second-order Reed-Muller code are punctured into length 30 by puncturing the 1st and the 17th bits; the remaining bits are denoted by bk, k=0,1,2, ..., 29 (k=29 corresponds to MSB).

    Encoder Structure for (32,10) Sub-code of
    Second-Order Reed-Muller Code
    In downlink, when the SF is lower than 128 the encoded and punctured TFCI, code words are repeated four times yielding 120 output bits. The two kinds of output code words are:
    • TFCIOut information without repetition:
    • TFCIOut information with repetition:
    Encoded TFCI bits are output into the output buffer.

References
  1. 3GPP Technical Specification TS25.212 V3.0.0, "Multiplexing and Channel Coding (FDD)," October 1999.
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