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