User Guide

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PAMS

Technical Documentation

NHD–4

System Overview

Page 3–34

Original 11/97

To calculate User B’s first data bit multiply (0 X –1) and (–2 X 1) which equals zero,

minus two waveform. Find the area under the curve, (0 + (–2)) / 2 = –1, which is

User B’s first data bit.

It has been stated that Walsh codes are orthogonal and that this property results in

zero cross talk between Walsh code signals. Using bipolar numbers multiply Walsh

code “00” with Walsh code “01”. Add the resulting area and divide by the number of

bit periods and you will get zero. Figure 33 illustrates this.

–1

CDMA15.DR

Walsh code

0 0

Walsh code

0 1

Figure 33. Definition of orthonogonality

Another and simpler way to state that Walsh codes are orthogonal is that since the

codes have an equal number of matches and mismatches, they are orthogonal.

The full 64–bit by 64 code Walsh code set 64 has been reproduced in the following

table.

Walsh Code Set W64

110

111

110

111

110

111

110

111

110

111

110

111

110

111

110

111

110

111

110

111

110

111

110

111

110

111

110

111

110

111

110

111

110