News





CDMA Interactive




PN Sequences
By Dr. Ernest Simo


1.0 Definition and Generation
Length of PN Sequences



In general, it can be demonstrated that the Maximum Length of a PN Sequence generated by an N-stage Linear Shift Register is:
  • L=2N-1
  • Where N is the number of stages of the Linear Shift Register.
Note that only suitable Tap Combinations will yield a Maximum Length sequence. in other words, a given Tap Combination or arrangement does not necessarily produce a Maximum Length Sequence.

Also note that the Linear Shift Register should not be seeded with an all zeros state: The Modulo-2 of two zeros yields another zero. This would result in a permanent state of zeros in the Linear Shift Register.


CODE: AN INTRODUCTION
By Dr. Ernest Simo
© 1999 DR. ERNEST SIMO - SPACE2000
BACK CONTENTS INDEX GLOSSARY NEXT BACK CONTENTS INDEX GLOSSARY NEXT