The normalized auto correlation ρxx(is defined as:
A. (rxx (l))/(rxx (0))
B. -(rxx (l))/(rxx (0))
C. (rxx (l))/(rxy (0))
D. None of the mentioned
Answer:A
The normalized auto correlation ρxx(is defined as:
A. (rxx (l))/(rxx (0)) B. -(rxx (l))/(rxx (0)) C. (rxx (l))/(rxy (0)) D. None of the mentioned
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 ρxx(l)= (rxx (l))/(rxx (0)).