Galileo OS SIS ICD.indd - GSA - Europa

Component
(Parameter Y)
Sub-carrier Type Sub-carrier Rate Ranging Code Chip-
Rate R C,E1-Y (Mcps)
R S,E1-Y,a (MHz) R S,E1-Y,b (MHz)
B CBOC, in-phase 1.023 6.138 1.023
C CBOC, anti-phase 1.023 6.138 1.023
Table 8. E1 SoL CBOC Chip- and Sub-carrier Rates
The navigation data message stream, after channel encoding, is transmitted with the
symbol rate as stated in Table 9.
Component
(Parameter Y)
Symbol Rate
R D,E1-Y (symbols/s)
B 250
C No data (‘pilot component’)
Table 9. E1 SoL Symbol Rates
The E1 SoL composite signal is then generated according to equation Eq. 11 below,
with the binary signal components e E1-B(t) and e E1-C(t). Note that as for E6, both pilot
and data components are modulated onto the same carrier component, with a power
sharing of 50 percent.
1
� � ��e�� t ��sc�� t � s c �� t � �
�� t e �� t � s c �� t � � s c �� t
sE 1 � E1�B
E1�B
, a
E1�B
, b E1�C
E1�C
, a � E1�C
, b
2
with c �� t � sgn�sin�2�Rt��
s X s,
X
© European Union 2010
Document subject to terms of use and disclaimers p. ii-iii
OD SIS ICD, Issue 1, February 2010
Eq. 11
The parameters α and β are chosen such as that the combined power of the sc E1-B,b
and the sc E1-C,b sub carrier components equals 1/11 of the total power of e E1-B plus e E1-C,
before application of any bandwidth limitation. This yields:
� �
10
11
and
One period of the sub-carrier function α sc E1-B,a (t) + β sc E1-B,b (t) for the E1-B signal
component and one period of the sub-carrier function α sc E1-C,a (t) − β sc E1-C,b (t) for the
E1-C signal component are shown in the following fi gure
a)
���
1
���
0
����
�1
����
0
1/6 1/2
t/T���1����
1
b)
� �
���
1
���
0
����
�1
����
0
1
11
1/6 1/2
t/T���1����
Figure 8. One period of the CBOC sub-carrier for a) the L1-B signal component, and b) the
L1-C signal component
1
9