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SN User's Guide - ESC Home - NASA

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Revision 10 B-2 450-<strong>SN</strong>UG<br />

DATA<br />

H<br />

NRZ-L<br />

L<br />

H<br />

NRZ-M<br />

L<br />

H<br />

NRZ-S<br />

L<br />

BI-L BI-L<br />

H<br />

L<br />

H<br />

BI-M BI-M<br />

L<br />

H<br />

BI-S BI-S<br />

L<br />

1 0 1 1 0 0 0 1 1 0 1<br />

Symbol period T (Symbol rate R = 1/T)<br />

Figure B-1. Digital Signal Formats<br />

Sequence of binary symbols (bits, chips) "1" and "0"<br />

Non-Return-to-Zero-Level<br />

"1" is represented by a high (H) level during the symbol period<br />

"0" is represented by a low (L) level during the symbol period<br />

Non-Return-to-Zero-Mark<br />

"1" is represented by a change in level<br />

"0" is represented by no change in level<br />

Non-Return-to-Zero-Space<br />

"1" is represented by no change in level<br />

"0" is represented by a change in level<br />

Bi-phase-L (Manchester II)<br />

A transition occurs at the middle of every symbol period<br />

"1" is represented by a midperiod transition from H to L<br />

"0" is represented by a midperiod transition from L to H<br />

Bi-phase-Mark<br />

A transition occurs at the beginning of every symbol period<br />

"1" is represented by a midperiod transition<br />

"0" is represented by no midperiod transition<br />

Bi-phase-Space<br />

A transition occurs at the beginning of every symbol period<br />

"1" is represented by no midperiod transition<br />

"0" is represented by a midperiod transition

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