User`s guide

Chapter 15 367
W-CDMA Uplink Digital Modulation for Receiver Test
Generating a Single PRACH Signal
5. Press Return > PRACH Timing Setup.
6. Configure the distance from the beginning of one preamble to the beginning of the next
preamble. This is expressed in access slots.
a. Move the cursor to highlight the Tp-p (time period between preambles) field.
b. Press
2 > Enter.
7. Set the transmission time interval for the message part.
a. Move the cursor to highlight the TTI (transmit time interval) field.
b. Press
10 > msec.
8. Press
Apply Channel Setup.
When the Apply Needed annunciator appears, press the
Apply Channel Setup softkey. You
will not see a change in the signal until you press this softkey.
Figure 15-14 Display After Time Parameter Changes
Modifying the Transport Layer
The transport channel (RACH) is available when the PRACH physical channel data type is
set to TrCh (factory default data type). This task teaches you how to make changes to the
transport layer parameters.
1. Press
Return > Return > Transport Setup > TrCH Setup.
2. Set the data block size.
The block size and the number of blocks affect the bit rate into the transport layer. The
data is punctured or has bits added (rate matching) so that it fits into a frame for a given