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WCDMA3G_SCGtoScrmb


Description: Convert one SCG index to eight primary scrambling codes
Library: 3GPPFDD 10-99, Common Physical Channels
Class: SDFWCDMA3G_SCGtoScrmb

Parameters

Name

Description

Default

Type

ChipRate

chip rate of the system: Chip Rate 3.84M

Chip Rate 3.84M

enum

Pin Inputs

Pin

Name

Description

Signal Type

1

SCG

index of one scrambling code group

int

Pin Outputs

Pin

Name

Description

Signal Type

2

Scrmb

a group of eight scrambling codes

multiple complex

3

Index

indices of eight scrambling codes

multiple int

Notes/Equations
  1. This model is used to convert the index of one scrambling code group to a group of 8 primary scrambling codes in downlink.
    Each firing, 38400 tokens of each Scrmb signal and one token of each Index signal are produced when one token of SCG is consumed.
  2. The Primary CCPCH is always transmitted using the primary scrambling code. There are 512 primary scrambling codes that are divided into 64 groups; each group consists of eight scrambling codes.
    Let

    SCG index be SCGid Œ (1, 2, ... , 64)

    primary scrambling code index be PSid Œ (0, 1, ... , 511).
    Then one SCGid corresponds to a group of eight primary scrambling codes whose indices are:

    PSid = ( SCGid −1) × 8 + (0, 1, ... , 7)

    The index of downlink scrambling code Sid = PSid × 16.
    There are two steps to convert an SCG index to a group of eight scrambling codes:
    • Form the index of SCG; the corresponding indices Sid of eight scrambling codes are known.
    • Generate the scrambling codes according to the indices obtained. For details regarding scrambling code generation, refer to WCDMA3G_DnLkAllocOVSF.

References
  1. 3GPP Technical Specification TS 25.213 V3.0.0, "Spreading and Modulation (FDD)," October 1999.
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