SATELLITE SYSTEMS - GPS Satellite Surveying - page 91

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TABLE 3.7 GPS, GLONASS, and Galileo Carrier Frequencies

Carrier Multiple of 10.23 Carrier Frequency [MHz]

L5 & E5A 115 1176.45

E5B 117.5 1202.025 (tentatively)

L2 120 1227.60

G 2 see (3.92) per satellite

E6 125 1278.750

L1, E1-L1-E2 154 1575.42

G 1 see (3.91) per satellite

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with the increasing demand for frequency space. For example, the WRC expanded the
bottom end of one of the radio navigation satellite services (RNSS) bands to between
1164 and 1260 MHz, putting E5A, E5B, and L5 under RNSS protection. Galileo
has also been assigned the range 1260 to 1300 MHz, labeled E6, at the lower L-band
region. At the upper L-band, two narrow bands, labeled E1 and E2, have been reserved
for Galileo adjacent to the GPS L1 band. Using BOC modulation techniques, it will
be possible to construct a Galileo signal that will have maximum spectral density at
E1 and E2 but cover the whole E1-L1-E2 band.
In order to make Galileo and GPS compatible, i.e., allow for the use of common
receiver components, the carrier frequency for the Galileo E1-L1-E2 will be 1575.42
MHz, which is the same as GPS L1. Similarly, E5A and L5 will use 1176.45 MHz as
the common carrier frequency.
The modulation (inhase and quadrahase) codes and chipping rate for the various
carriers must still be finalized. The remaining issues regarding frequency allocation
and signal structure are expected to be resolved at a future WRC. Whereas L5, E5, L1,
and G1 are within the ARNS bands the middle bands (L2, G2, and E6) currently do
not enjoy such a protected status. There is a potential for interference from joint tacti-
cal information distribution system (JTIDS), multifunctional information distribution
system (MIDS), distance measuring equipment (DME), and tactical air navigation
system (TACAN) that requires attention. Table 3.7 summarizes the location of the
carrier frequencies.

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