Instruction Manual

Chapter 5 Modulated Waveform Output RIGOL
DG4000 Series User’s Guide
5-21
To Select Modulating Waveform Source
BPSK uses internal modulation source. Press Data Source to select PN15, PN21,
01 or 10and the default is PN15.
Explanation:
PN sequence (Pseudo
-
noise Sequence), a kind of periodic bianary sequence,
has
the statistical characteristics similar to a random noise but can be
produced and processed repeatedly. The most commonly used PN sequence
is m sequence generated by shift register
s
with linear feedback and its period
is relevant to the linear feedback logic and the initial state of each
register.
The period of the m sequence generated by n
-level shift register is 2
n
-1
. As
In the figure below is a 4
-level linear feedback shift register of which the
feedback logic is
a3a2. For PN15 and PN21, 15 and 21are levels of the
registers.
a3
a2
a1
a0

Output
To Set BPSK Rate
BPSK uses internal modulation source. Press Rate to set the frequency at which
the output phase shifts between “carrier phase” and “modulating phase”.
z Use the numeric keyboard or direction keys and knob to input the desired
frequency value.
z The frequency range is from 2mHz to 1MHz and the default is 100Hz.
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