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To select modulating waveform source, To set bpsk rate – RIGOL DG4000 Series User Manual

Page 121

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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 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.