WCDMA3G_CRCDecoder
Description: CRC check of transport block
Library: 3GPPFDD 10-99, Channel Coding
Class: SDFWCDMA3G_CRCDecoder
Parameters
Name |
Description |
Default |
Type |
|---|---|---|---|
TrCHType |
transport channel type: DCH_8_kbps, DCH_16_kbps, DCH_32_kbps, DCH_64_kbps, DCH_128_kbps, DCH_256_kbps, DCH_512_kbps, DMCH_2_4_kbps, DMCH_12_2_kbps, DMCH_64_kbps, DMCH_144_kbps, DMCH_384_kbps, DMCH_2048_kbps, BCH_11_1_kbps, BCH_12_3_kbps |
DCH_8_kbps |
enum |
TTI |
transmission time interval: TTI_10ms, TTI_20ms, TTI_40ms, TTI_80ms |
TTI_10ms |
enum |
CRC |
number of CRC bits to be added: NoCRC, CRC_8_bits, CRC_12_bits, CRC_16_bits, CRC_24_bits |
CRC_16_bits |
enum |
Pin Inputs
Pin |
Name |
Description |
Signal Type |
|---|---|---|---|
1 |
DataIn |
transport block with CRC bits attached in tail |
int |
2 |
TF |
transport format |
int |
Pin Outputs
Pin |
Name |
Description |
Signal Type |
|---|---|---|---|
3 |
DataOut |
transport block after removing the CRC bits |
int |
4 |
CRCError |
CRC checking error indicator |
int |
Notes/Equations
- The model is used to perform CRC checking of a block of transport channel data. The signal processing procedure follows the CRC checking algorithms described in [1].
Since the length of the transport block could dynamically change, the number of tokens consumed at DataIn is set to the maximum block length plus the number of CRC parity bits attached, and the number of tokens produced at DataOut is set to the maximum block length. The maximum block length is determined by the TrCHType and TTI parameters. - Each firing, a block of data with the CRC parity bits attached in reversed order is input for CRC checking, and the output block is the data block while the CRC parity bits have been removed. One token is consumed at pin TF, which acts as the instantaneous service rate indicator. So, the number of useful bits, or the length of input data block for CRC coding, is determined by TF. For details regarding transport formats, refer to General Signal Processing.
One token is produced at pin CRCError: 0 indicates the result is correct; 1 indicates an error.
References
- 3GPP Technical Specification, TS 25.211, V3.0.0, "Physical channels and mapping of transport channels onto physical channels (FDD)," October, 1999.