3GPPFDD_PRACHSprd
Description: Uplink PRACH spreading and scrambling
Library: 3GPPFDD, PhyCH Multiplexers & Coders
Class: SDF3GPPFDD_PRACHSprd
Derived From: 3GPPFDD_ULPhyCHBase
Parameters
Name |
Description |
Default |
Unit |
Type |
Range |
|---|---|---|---|---|---|
SpecVersion |
version of specifications: Version_03_00, Version_12_00, Version_03_02 |
Version_12_00 |
|
enum |
|
ScrambleCode |
index of scramble code |
0 |
|
int |
[0:512] for downlink; |
PrmblSgntr |
Preamble Signature |
0 |
|
int |
[0, 15] |
Pin Inputs
Pin |
Name |
Description |
Signal Type |
|---|---|---|---|
1 |
CtrlIn |
DPCCH part |
int |
2 |
GainD |
gain factor of DPDCH |
real |
3 |
GainC |
gain factor of DPCCH |
real |
4 |
SltFin |
DPDCH slot format |
int |
5 |
Data |
data |
int |
Pin Outputs
Pin |
Name |
Description |
Signal Type |
|---|---|---|---|
6 |
out |
data |
complex |
Notes/Equations
- This model is used to spread and scramble message part of PRACH. The following figure illustrates the process.
Spreading and Scrambling of PRACH Message Part
- The preamble signature s , 0 ≤ s ≤ 15, points to one of the 16 nodes in the code-tree that corresponds to channelization codes of length 16. The sub-tree below the specified node is used to spread the message part. The control part is spread with the channelization code cc of spreading factor 256 in the lowest branch of the sub-tree, i.e. cc = Cch,256,m where m = 16 × s + 15. The data part is spread by channelization code cd =Cch,SF,m and SF is the spreading factor used for the data part and m = SF × s/16.
- The n th PRACH message part scrambling code, denoted Sr-msg,n, where n = 0, 1, ... , 8191, is based on the long scrambling sequence as defined in [2].
References
- 3GPP Technical Specification TS 25.211 V3.10.0, Physical channels and mapping of transport channels onto physical channels (FDD), March 2003, Release 1999.
- 3GPP Technical Specification TS 25.213 V3.7.0, Spreading and modulation (FDD), March 2003, Release 1999.
http://www.3gpp.org/ftp/Specs/2002-03/R1999/25_series/25213-370.zip