Agilent Technologies E4428C, User Manual, Page: 455 / 700

Chapter 15 431
W-CDMA Digital Modulation for Component Test
W-CDMA Concepts
Understanding TPC Values
TPC values determine how the transmit power of the receiving base or mobile station will vary. In the
channel table editor, TPC values are represented in hexadecimal format to simplify entries and
modifications.
Figure 15-10 shows the channel table editor with the TPC value, 7F80, highlighted.
Figure 15-10 Highlighted TPC Value
Hexadecimal TPC values are converted to their binary equivalent. In this example, the value 7F80 becomes
111 1111 1000 0000. Notice that there are 15 digits in the binary TPC value. Because one frame contains
15 timeslots, one binary digit is assigned to each timeslot (see
Figure 15-11 on page 432 ). The assigned bit is
then repeated enough times to fill the TPC bit field (see the N
TPC
column of Table 15-7 ). Since the example
in Figure 15-11 uses two TPC bits per timeslot, the values are either 11 or 00.
The TPC bits that are ones direct the receiving base or mobile station to increase its transmit power by an
amount specified by the W-CDMA standard. Likewise, TPC bits that are zeros cause the power to decrease
by the same amount. In this example, the transmit power is increasing over timeslots 0 through 7 and
decreasing over timeslots 8 through 14.