Enhanced Functions For Digital Standard 3GPP W-CDMA (FDD)
SMIQ
1125.5555.03
2.242
E-9
Generation principle of channel-coded P-CCPCH with system frame number
With Enhanced P-CCHCP/BCH State On, channel coding activated (Channel Coding State On) and with
P-CCPCH State under Specific Enhanced Channel Settings On, the SMIQ generates a channel-coded
P-CCPCH (i.e. a broadcast channel BCH) according to the following principle:
BCH Channel Coding
SFN
(11 bit)
Sys Info
(235 bit)
. . .
BCH Transport Block 0 (20 ms)
BCH Transport Block 2047 (20 ms)
Counting SFN
User selectable data (e.g. data list)
Coded BCH Transport Block 0
Coded BCH Transport Block 2047
P-CCPCH Frame 0
P-CCPCH Frame 1
P-CCPCH Frame 4094 P-CCPCH Frame 4095
P-CCPCH Slot 0
P-CCPCH Slot 1
P-CCPCH Slot 14
. . .
. . .
. . .
SFN
(11 bit)
Sys Info
(235 bit)
Fig. 2-169
Generation principle P-CCPCH/BCH
The data blocks of BCH at transport-channel level comprise data determined for 20 ms of the P-CCPCH
(i.e. 2 frames) after channel coding. The first field of such a data block is an 11-bit long field for the
system frame number (SFN). The SFN is automatically incremented by 1 (as stipulated in the standard)
from transport block to transport block (equivalent to a step width of 2 frames due to the transport time
interval length of 20 ms). After 2048 transport blocks (equivalent to 4096 frames) SFN is reset and
starts again at 0 (SFN restart). An output trigger indicating the SFN restart can be generated (see
2.14.2.1).
The SFN format is defined in [6], sections 10.2.48, 11.2 (page 578) and 11.3 (page 691). It is MSB-first
coded.
The remaining system information (a 235-bit long field per block) is filled from the data source selected
for the P-CCPCH under Specific Enhanced Channel Settings.
A data list can be used to transmit further specific system information in addition to the SFN. If only the
SFN is required,
ALL 0
is recommended as data source for P-CCPCH.
The BCH transport blocks are then channel-coded. A coded transport block comprises the data
sequence for two P-CCPCH frames.