Galileo OS SIS ICD.indd - GSA - Europa

8. Annex C - Galileo E1 and E5 Memory Codes
C.1. Introduction
This annex provides the optional memory based primary codes (expressed in
hexadecimal format) for the Galileo Open Signal components E5a-I, E5a-Q, E5b-I,
E5b-Q, E1-B, E1-C.
C.2. Hexadecimal Coding Convention
Generally, one hexadecimal symbol (0,..,9, A,..,F) corresponds to four succeeding
code-chips. The leftmost code-chip corresponds to the fi rst code-chip in time, and the
rightmost code-chip corresponds to the last code-chip in time. The fi rst group is built
with the fi rst four code-chips, the second group with the fi fth to eighth code-chip etc.
For primary codes whose length is not dividable by four, the last hexadecimal symbol
is built from the last group of code-chips, fi lled up with zeros at the end in time (to the
right) to reach a fi nal length of 4 binary symbols. The translation from the chip-stream
to hexadecimal symbol stream is illustrated with an example code of length 10 in the
next table.
Time (in Chip) 1 2 3 4 5 6 7 8 9 10 11 12
Logic Representation
of Chip-Values
Logic Representation
Filled up with Zeros
at the End
Logic to Decimal
Translation
Decimal
Representation
Hexadecimal
Representation
1 1 1 0 1 1 0 0 0 1 - -
1 1 1 0 1 1 0 0 0 1 0 0
x4 x2
x8 x1
x4 x2
x8 x1
14 12 4
E C 4
58 © European Union 2010
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OD SIS ICD, Issue 1, February 2010
x4 x2
x8 x1
Table 80. Example for the Translation of Logical (binary) Spreading Code into Hexadecimal
Representation
The following table summarizes these code properties.