CORRELATION IN DIGITAL SIGNAL

[rectifier]

two digital signals correlation

CAN ANY ONE TELL HOW TO VERIFY CORRELATION PROPERTY FOR DIGITAL SIGNALS?

 

[rectifier]

Hey people,
I need a quick help in this topic please...

 

[oz]

see this link for a pretty good intro to correlation:

**broken link removed**

 

[m_llaa]

I am familiar with correlation, but what u realy want? explain more plz

 

[vjfaisal]

kindly tell me basics and the importance of correlations


best regards

 

[jakjoud]

Ok, In fact the correlation is a kind of multiplication between two vectors, it's commonly used to measure the similarity of the two signals.
It can be write as:

For exemple if we consider a pulse that propagate and we have this pulse at two different moment. The correlation between the two vectors (the signal at the two moment) presents maximum at the difference of the two moments which can be a great tool to measure the propagation speed.
In fact there is also two dimensional correlation which is used essentially in the patterns recognition.
I hope I did help!

 

[vjfaisal]

kindly tell me basics and the importance of correlations


best regards

 

[holyshoot]

Refer Page no. 177& 178 of B. P. Lathi, Signal Processing and Linear Systems, Berkeley-Cambridge, 1998.

 

[m_llaa]

Hi
jakjoud is correct.
correlation in signal space like inner product in vector space. correlation show similarity percent between 2 signals or between 1 signal with its delayed copy of that.

 

[rectifier]

I wanted to know what is the correlation coefficient between two binary sequences.
For eg: seq 1: 1100101
seq 2: 1011011

Regards,
R.

 

[jakjoud]

I think Correlation is a function not a coefficient.
In your case :
Each seq is 7 elements
Then the function of correlation is a 2*7-1=13 elements.

seq1: 1 1 0 0 1 0 1
seq2: 1 0 1 1 0 0 1

the correlation of the twe sequences: 1 1 0 1 3 1 2 2 1 1 2 0 1

It's calculated by the relation I gived last time

 

[rectifier]

I think Correlation is a function not a coefficient. [

I didn't quite get this. Then how do we calculate how much the two signals are correlated. Isn't the correlation coefficient give the answer to that?

 

[m_llaa]

Hi
u can catch maximum of correlation function for your maximum similarity between your signals.
I recommend u see spread spectrum book to learn more about it.

 

[correlator2006]

the correlation property state that if u have 2 orthognal signals (Φn,Φm) with period T then :

T
correlation between 2 signals ∫ ΦnΦm dt
0 T
IF Φn and Φm are orthognal then ∫ ΦnΦm dt not equal 0 if n=m,0 otherwise
0
correlation theorty is widley used in demodulation of passband signals like M-ary PSK,m-ARY QAM
for more details please revise proakis book (Digital communications,chapter 4 and 5) or simon hyken 2nd edition (chapter 5 and chapter 7)

 

[rectifier]

seq1: 1 1 0 0 1 0 1
seq2: 1 0 1 1 0 0 1

the correlation of the twe sequences: 1 1 0 1 3 1 2 2 1 1 2 0 1

What does the above sequence 11013122.... tell about the correlation of two given sequences? Plz explain.

 

[music_lover04]

seq1: 1 1 0 0 1 0 1
seq2: 1 0 1 1 0 0 1

the correlation of the twe sequences: 1 1 0 1 3 1 2 2 1 1 2 0 1

What does the above sequence 11013122.... tell about the correlation of two given sequences? Plz explain.

This is a Uni-Polar sequence. so the correlation can be done using XOR
XORin sequence one and two and adding.

0+1+1+1+1+0+0=4
so the correlation is 4
note:
If the XORed sum is zero then the two sequence are said to be orthogonal.
Hope i have answered ur question