# Chapter 2 – Binary PN Sequences

# 2.1 Introduction

By far the most widely known binary PN sequences are the maximum-length shift-

register sequences. A maximum-length shift-register sequence, or m-sequence, has a length of

n= 2^{n }– 1 bits, where m is the number stages in a shift register with linear feedback (as seen in

Figure 2 below).

# Figure 2 - M-stage Binary Sequence Generator [12]

2.2 Analysis Method – Autocorrelation

An important characteristic of a periodic PN sequence is the periodic autocorrelation function.

# Correlation refers to the relation is the mutual relationship between two or more random

variables. Thus, autocorrelation is the correlation of a signal with itself. Autocorrelation is

useful for finding repeating patterns in a signal, such as determining the presence of a periodic

9