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x(n)=4γ(n)+3γ(n-1)+2γ(n-2)+γ(n-3)is a six point sequence. i) Find p(n),if P(K)= W_N^2K X(K) ii) If Q(K)=X(K-3),Find q(n)
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written 6.5 years ago by |
x(n)={4,3,2,1,0,0}
i) Find p(n)=ifP(K)= W2NKX(K)
Above statement signifies, circular time shift properly.
x(n−l)(↔)DFTW2K6X(K)
By comparison we have,
l=2 ,N=6
p(n)=x(n-2)
P(n)={0,0,4,3,2,1}
ii) If Q(K)=X(K-3),Find q(n)
Above statement signifies circular frequency shift.
x(n)e−j2πKl(N(↔)DFTX(K−l)
By comparison we have,
l=3
q(n)=x(n)e−j2πln6
q(n)=x(n).e−jπn
q(0)=x(0)e0=4
q(1)=x(1)e−jπ=−3
q(2)=x(2)e−2jπ=2
q(3)=x(3)e−3jπ=−1
q(4)=x(4)e−4jπ=0
q(5)=x(5)e−5jπ=0
q(n)={4,-3,2,-1,0,0}