To demodulate a non-standard-format signal
This task uses a 16 QAM signal from the Signals Disk to teach you how to
demodulate a non-standard signal. The task uses digital demodulation. If
you want to perform this task using video demodulation, choose video
demodulation instead of digital demodulation in step 4. The Video
Demodulation Concepts (Opt. AYH) chapter explains how video
demodulation differs from digital demodulation.
1. Initialize the analyzer:
Press [
Instrument Mode
], [
receiver
], then press:
89410A: [
input section (0-10 MHz)
].
89441A: [
RF section (0-10 MHz)
].
Press [
Preset
].
Press [
Instrument Mode
], [Vector]
2. Load “16QAM.DAT” from the Signals Disk and play it through the arbitrary
source:
Perform steps 1, 2, and 3 in ‘’To prepare a digital demodulation
measurement’’ in chapter 6. For step 2, load the “16QAM.DAT” signal
from the Signals Disk instead of ‘’PI4DQPSK.DAT.’’
3. Select appropriate setup parameters:
Press [
Range] and select the optimum range.
Press [
Frequency
], [
center
], 500, [
kHz
]
Press [
span
], 78, [
kHz
].
Press [
Trigger
], [
trigger type
], [
internal source
], [
return
], [
ch1 delay
], 150 [
us
].
If you don’t know how to select the optimum range, see ‘’To prepare a
digital demodulation measurement’’ in chapter 6.
4. Digitally demodulate the signal:
Press [
Instrument Mode
], [
Digital Demodulation
] (with option AYH, press
[
Instrument Mode
], [
demod type
], [
Digital Demodulation
], [
Return] ).
Analyzing Digitally Demodulated Signals (Options AYA and AYH)
10 - 2