Chapter 16 477
W-CDMA Uplink Digital Modulation for Receiver Test
Multiple PRACH Overview
There are multiple ways the ESG can trigger external measurement equipment for measuring the multiple
PRACH signal. Some examples of these are shown in the following list:
80 ms frame pulse This coincides with the frame boundaries for SFN mod 8=0.
10 ms frame pulse This denotes the SFN frame boundaries.
Preamble pulse This indicates the beginning of the access slot for each preamble transmission.
Message pulse This signifies the start of an access slot where the message part is being transmitted.
PRACH pulse This denotes the access slot boundaries between PRACH repetitions.
Refer to “PRACH Mode” on page 560 for more information on trigger signals.
Understanding the Power Offset Between the Carrier and the Multiple PRACH
The ESG has an 18.06 dB offset between the ESG carrier power and the multiple PRACH power level. This
offset is shown by the PRACH power level in the PRACH Power Setup display. This is demonstrated in
Figure 16-22 where the carrier power is 0.0 dBm and the PRACH power is −18.06 dBm
(0.0 dBm − (−18.06 dBm) = 18.06 dB offset). Since the data part power has been turned off, the PRACH
power is shown in both the Max Pwr field (preamble power) and the Msg Pwr field (message part power)
as indicated in the figure.
Figure 16-22 Offset Power
PRACH Power—18.06 dB Offset from Carrier Power
ESG Carrier Power