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WCDMA3G_DnLkSpreading


Description: Downlink spreading and scrambling
Library: 3GPPFDD 10-99, Base Station
Class: SDFWCDMA3G_DnLkSpreading

Parameters

Name

Description

Default

Sym

Type

Range

SF

spreading factor: SF_4, SF_8, SF_16, SF_32, SF_64, SF_128, SF_256, SF_512

SF_256

NSF

enum

 

UseExtSpreadingCode

use external spreading code: Yes, No

No

 

enum

 

SpreadingCodeIndex

spreading code index

0

 

int

[0, NSF -1]

ScramblingCodeIndex

scrambling code index

0

 

int

[0, 8191]

Pin Inputs

Pin

Name

Description

Signal Type

1

In

input data

complex

2

SpreadingCodeExt

external spreading code

int

Pin Output:

Pin

Name

Description

Signal Type

3

Out

output data

complex

Notes/Equations
  1. This subnetwork model is used to perform spreading and scrambling in downlink.
    The schematic for this subnetwork is shown in the following figure. Input data is spread by the spreading code generated by WCDMA3G_OVSF or input by pin SpreadingCodeExt; data is then multiplied by the scrambling code generated by WCDMA3G_DnLkScrambling.
    When UseExtSpreadingCode = Yes, the spreading code is input through pin SpreadingCodeExt; otherwise, WCDMA3G_OVSF generates the spreading code.
    Refer to the following table for the values of NSF.
    NSF Values

    SF Parameter

    NSF

    SF_4

    4

    SF_8

    8

    SF_16

    16

    SF_32

    32

    SF_64

    64

    SF_128

    128

    SF_256

    256

    SF_512

    512


    WCDMA3G_DnLkSpreading Schematic

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