WCDMA3G TFCIEncoder

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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

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, 2^TFCIBitsNum - 1].

TFCI Encoder
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 (C_32,1, C_32,2, C_32,4, C_32,8, C_32,16); 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.