User's Manual

GSM/GPRS/GNSS Module Series
MC20 Hardware Design
MC20_Hardware_Design Confidential / Released 93 / 95
9 Appendix B GPRS Coding Schemes
Four coding schemes are used in GPRS protocol. The differences between them are shown in the
following table.
Table 43: Description of Different Coding Schemes
Scheme
Code
Rate
USF
Pre-coded
USF
Radio Block
excl.USF and
BCS
BCS Tail
Coded
Bits
Punctured
Bits
Data
Rate
Kb/s
CS-1 1/2 3 3 181 40 4 456 0 9.05
CS-2 2/3 3 6 268 16 4 588 132 13.4
CS-3 3/4 3 6 312 16 4 676 220 15.6
CS-4 1 3 12 428 16 - 456 - 21.4
Radio block structure of CS-1, CS-2 and CS-3 is shown as the figure below.
Figure 50: Radio Block Structure of CS-1, CS-2 and CS-3
Rate 1/2 convolutional coding
Puncturing
456 bits
USF
BCS
Radio Block