Barker code
From Wikipedia, the free encyclopedia
A Barker code is a sequence of N values of +1 and −1,
- aj for
such that
for all 
.
Here is a table of all known Barker codes, where negations and reversals of the codes have been omitted:
| Length | Codes | |
|---|---|---|
| 2 | +1 −1 | +1 +1 |
| 3 | +1 +1 −1 | |
| 4 | +1 −1 +1 +1 | +1 −1 −1 −1 |
| 5 | +1 +1 +1 −1 +1 | |
| 7 | +1 +1 +1 −1 −1 +1 −1 | |
| 11 | +1 +1 +1 −1 −1 −1 +1 −1 −1 +1 −1 | |
| 13 | +1 +1 +1 +1 +1 −1 −1 +1 +1 −1 +1 −1 +1 | |
Barker codes of length 11 and 13 are used in direct-sequence spread spectrum and Pulse Compression Radar systems because of their low autocorrelation properties.
Barker codes utilize biphase modulation; that is, the change of phase in the carrier wave is 180 degrees.
[edit] See also
[edit] References
- Barker Code — Mathworld
