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CDMA Interactive




PN Sequences
By Dr. Ernest Simo


1.0 Definition and Generation
Generation of (PN) Sequences


Let us conduct a second experiment similar to the first experiment with the exception of the Taps Connections:
  • Seed stages 1, 2, and 3 of the Linear Shift Register with 0, 0, and 1 respectively. Note that 001 represents the least significant number.
  • Connect Tap #2 and Tap #3 to the input of the Modulo-2 adder.
  • Drive the Linear Shift Register with a clock.
The resulting States of the Shift Register for various Time-shifts are:

TIME-SHIFTS
0   0   0   1
1   1   0   0
2   0   1   0
3   1   0   1
4   1   1   0
5   1   1   1
6   0   1   1
7   0   0   1

The output sequence Cj(t)= 1 0 0 1 0 1 1 repeats itself after 7 shifts and is referred to as a PN Sequence or PN Code.


CODE: AN INTRODUCTION
By Dr. Ernest Simo
© 1999 DR. ERNEST SIMO - SPACE2000
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