Talk:Barker code

no longer Barker codes exist?

Mathworld says it is conjectured that no longer Barker codes exist. Shouldn't the article be changed to reflect that, since mathworld is the only source listed? —Preceding unsigned comment added by 146.6.203.178 (talk) 22:37, 24 March 2009 (UTC)[reply]

i have a question of the barker code could we follow the rule to the barker code 5 (+-+-+)?

optimal Barker code

Currently this article states

Here is a table of all known optimal Barker codes, where negations and reversals of the codes have been omitted. Optimal is defined as having a maximum autocorrelation of 1 (when codes are not aligned).

That implies there exists some "Barker code" that is not an "optimal Barker code". I think that every Barker code is an "optimal" Barker code. So I am removing all mentions of "optimal". (If there exists some "Barker code" that is not an "optimal Barker code", please revert my edit and list that example in the article.) --68.0.124.33 (talk) 02:42, 1 August 2008 (UTC)[reply]

Method to verify codes

Maybe it would be usefull to add this simple method, by which it is posibble to verify a code if it is a Barker-code:

Let there be N numbers a1, a2, a3, ......, aN where every a equals either +1 or -1.

Pick a number k where 1 <= k <N.

Write down the first k a's, in order, then write down the last k a's in order. For k=3 you would write down

a1, a2, a3

a(N-2), a(N-1), aN.

Now multiply corresponding numbers and add (dot product):

a1 a(N-2) + a2 a(N-1) + a3 aN.

It's a Barker code if that sum is always (for every k) equal to 0, 1 or -1.

from: [1] --Grapestain (talk) 23:18, 26 May 2009 (UTC)[reply]