Agilent Technologies E4428C, Руководство пользователя

Страница: 661 / 700

Chapter 17 637
W-CDMA Downlink Digital Modulation for Receiver Test
W-CDMA Downlink Concepts
Figure 17-36 E
c
/N
o
Reference Selection
When E
c
/N
o
is 0.0 dB, C/N is equal to the reference channel power. This is demonstrated in the following
C/N formula:
C/N = (Ec Ref Pow - E
c
/N
o
)
The total noise power in a 3.84 MHz bandwidth is calculated using the following formula:
T
p
= 10 Log[(C
w
+ N
w
) / .001]
T
p
= total noise power (dBm)
C
w
= linear carrier power (watts) across the 3.84 MHz bandwidth
N
w
= linear noise power (watts) across the 3.84 MHz bandwidth
These formulas clearly show the relationship between E
c
/N
o
and C/N and their effect on the total noise
power across the 3.84 MHz bandwidth.
Ec/No Channel Selection
Channel Reference and Channel Noise Power Reference Fields