RIGOL DG5000 Series - Manual (Page 103)

Chapter 5 IQ Modulation Output RIGOL
User’s Guide for DG5000 5-5
To Select Code Pattern
When internal modulation is selected, users could select the internal pre-defined or
user-defined code patterns.
Pre-defined PN Sequence Code Pattern
PN sequence (Pseudo-noise Sequence, pseudo random noise sequence) is a periodic
binary sequence approximation. It has some statistic characteristics similar to random
noise and it can be generated and processed repeatedly. The most commonly used PN
sequence is the Longest Linear Feedback Shift Register, that is, m sequence generated
by shift register 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
1 - 2
n .
The generator pre-defines four conventional PN sequences. When internal modulation
is selected, press Pattern
to select one PN sequence: PN9, PN11, PN15 or PN23,
where 9, 11, 15 and 23 are the orders of the shift registers, and different PN code is
generated based on different linear feedback.
 PN9:Q5
⊕ Q9.
 PN11: Q9
⊕ Q11.
 PN15: Q14
⊕ Q15.
 PN23: Q18
⊕ Q23.
Pre-defined Fixed 4 bits Code Pattern
Fixed4 can be used to define a 4-bits repeat sequence code pattern to provide a
continuous data flow.
When internal modulation is selected, you can press Pattern  Fixed4, use knob to
change the code pattern. The adjustment range is from 0000 to 1111.