Question 1
Marks : +2 | -2
Pass Ratio : 100%
What is the energy sequence of the signal ax(n)+by(n-l) in terms of cross correlation and auto correlation sequences?
Explanation: The energy signal of the signal ax(n)+by(n-l) is
Question 2
Marks : +2 | -2
Pass Ratio : 100%
The normalized auto correlation Ïxx(l) is defined as _____________
Explanation: If the signal involved in auto correlation is scaled, the shape of auto correlation does not change, only the amplitudes of auto correlation sequence are scaled accordingly. Since scaling is unimportant, it is often desirable, in practice, to normalize the auto correlation sequence to the range from -1 to 1. In the case of auto correlation sequence, we can simply divide by rxx (0). Thus the normalized auto correlation sequence is defined as Ïxx(l)=\\(\\frac{r_{xx}(l)}{r_{xx}(0)}\\).
Question 3
Marks : +2 | -2
Pass Ratio : 100%
What is the cross correlation sequence of the following sequences?
{10,9,19,36,-14,33,0,7,13,-18,16,7,5,-3}
{10,-9,19,36,-14,33,0,7,13,-18,16,-7,5,-3}
{10,9,19,36,14,33,0,-7,13,-18,16,-7,5,-3}
{10,-9,19,36,-14,33,0,-7,13,18,16,7,5,-3}
Explanation: We know that rxy(l)=\\(\\sum_{n=-\\infty}^{\\infty} x(n)y(n-l)\\) where l=0,±1,±2,…
Question 4
Marks : +2 | -2
Pass Ratio : 100%
What is the auto correlation of the sequence x(n)=anu(n), 0<a<l?
Question 6
Marks : +2 | -2
Pass Ratio : 100%
What is the relation between cross correlation and auto correlation?
Explanation: We know that, a2rxx(0)+b2ryy(0)+2abrxy(l) ≥0
Question 10
Marks : +2 | -2
Pass Ratio : 100%
The cross correlation of two real finite energy sequences x(n) and y(n) is given as __________
Explanation: If any two signals x(n) and y(n) are real and finite energy signals, then the correlation between the two signals is known as cross correlation and its equation is given as