Appendix A Outdoor GPS Antenna Installation
Verizon 4G LTE Network Extender 2 for Enterprise User Guide v1.0
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Avoiding Interference
If more than one antenna for other communications, such as an antenna for a base
station or satellite communication, is installed in the surroundings, the GPS
antenna must be installed in a location to which no interference signals flow in.
If interference exists within the GPS L1 frequency bandwidths (1575.42 ± 1
MHz), you should use a band pass filter to prevent them from affecting it.
Furthermore, if the GPS antenna is installed by a transmitter which operates with a
bandwidth similar to the GPS L1 frequency, the possibility of interference
increases (in this case, interference is caused by harmonics). If the GPS antenna
has a problem due to interference, you must move it to a different location where
interference signals can be avoided or minimized in strength.
Inband Noise
Inband noise includes narrowband noise and wideband noise that occur in an
inband width. (L1, 1575.42 ± 1 MHz)
- Narrowband noise in an inband width: If it is higher than 108 dBm, it can affect
the operation of the GPS receiver.
- Wideband noise in an inband width: It may not be detected by a measuring
instrument and impair the sensitivity of the GPS receiver, and thus affect its
operation.
If there is an outband interference problem, you can reduce the effects of
interference on the GPS receiver by applying one or more L1 GPS band pass
filters.
The filter should be installed at the following locations:
•
The input connector of the Samsung GPS receiver
•
Behind the antenna or the front end of a line amplifier
The filters above are used to reject jamming tones for outband signals. If
interferences actually occur in the inband signals, they will result in serious
consequences.
