Nera Inmarsat-c, Service Manual, Page: 146 / 228

AP1.3 Channel types and Signal processing
AP1-25
Fig. AP1.3.10 Permuting
Preambling
For easy synchronization at the receiving side, the preamble is added to the top of the
message channel data. Preamble consists of the carrier recovery (128 bits) and the
clock regeneration (64 bits).
Preamble
carrier recovery : 128bits
all = 1 clock regeneration :
64bits
UW DATA UW DATA UW DATA
……………
1sd frame 2nd frame
n frame
(max : 50)
10240bits 128bits
Fig. AP1.3.11 Preambling
0 1 2
………………………………
161
0
1
2
63
62
:
:
:
:
:
:
:
:
Column
Row
25 row 0 row
1
2
3
64
65
66
67
128
10177
10177
10177
10240
10239
63 127
39 row
………………
( 1st frame ) ( Last frame )