Anrtisu Cell Master MT8212B, User Manual, Page: 225 / 294

the base station or it can be recovered from GPS when a GPS antenna is connected to the
Cell Master.
q
GPS Auto
— The Cell Master uses GPS as the timing reference, and automat-
ically detects the strongest pilot. The Anritsu GPS antenna must be connected
to the Cell Master GPS antenna connector. GPS must be turned on under
Sys|GPS|GPS On/Off
and the GPS must be locked to the satellites before
GPS Auto can be used.
NOTE: Refer to Chapter 12 for more information on GPS.
q
GPS Manual
— The Cell Master uses GPS as the timing reference, but it
searches only for the specified PN. The GPS antenna must be connected to
the Cell Master GPS antenna. GPS must be turned on under
Sys|GPS|GPS
On/Off
and the GPS must be locked to the satellites before GPS Manual can
be used.
q
External Auto
— The Cell Master uses an external even second time mark as
the timing reference. The time mark is usually available at the base station on
a BNC connector labeled as "ESTM" or "PP2S." The ESTM must be con-
nected to the
CDMA Timing Input
connector on the Cell Master. The Cell
Master will automatically detect the strongest pilot.
q
External Manual
— The Cell Master uses an external even second time mark
as the timing reference. This is usually available at the base station on a BNC
connector labeled as "ESTM" or "PP2S". This ESTM must be connected to
the
CDMA Timing Input
on the Cell Master. The Cell Master will search only
for the specified PN.
q
No Trigger
— If both GPS and external timing are unavailable, you may
choose No Trigger for the PN search.
Walsh Codes
— The user may select 64 or 128 Walsh codes for display. A cdmaOne trans-
mitter displays 64 walsh codes and CDMA2000 1xRTT transmits 128 walsh codes. In 128
Walsh codes mode the Cell Master displays code domain power in bit reversed order. This
is useful with CDMA2000 signals, where a single user may use several codes (supplemen-
tal channels) which appear adjacent in the bit reversed order, but not in the standard order.
In that case, the Cell Master draws them as a single bar with no spaces in between.
PN Increment
— The PN Increment determines how close together PNs can be. For in-
stance, if the PN increment is chosen as 4, a measured PN of 9 will be displayed as a PN of
8 with a larger timing error (Tau). PN Increment is useful in over the air testing, where the
propagation delay can shift a PN. Most networks have a PN increment they use to space out
the PNs of their base stations. For conducted measurements, the PN increment is usually set
to 1.
Advanced Settings
— Advanced settings include the measurement length and the external
trigger polarity.
q
Meas Length
— Sets the length of the measurement. Longer measurement
lengths take longer, but are more stable. Shorter measurement lengths may
produce less stable results.
q
Ext Trigger Polarity
— The CDMA timing input can use the rising edge or the
falling edge of the ESTM as the zero point in time.
Chapter 13 CDMA Measurement
13-3