To select modulating waveform source, To set bpsk rate – RIGOL DG4000 Series User Manual
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Chapter 5 Modulated Waveform Output
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 registers 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”.
Use the numeric keyboard or direction keys and knob to input the desired
frequency value.
The frequency range is from 2mHz to 1MHz and the default is 100Hz.