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What is the convolution of the sequences of x1(n)=x2(n)={1,1,1}?(a) {1,2,3,2,1}(b) {1,2,3,2,1}(c) {1,1,1,1,1}(d) {1,1,1,1,1}This question was posed to me by my school teacher while I was bunking the class.My question is based upon Properties of Fourier Transformfor Discrete Time Signals topic in division Frequency Analysis of Signals and Systems of Digital Signal Processing |
Answer» CORRECT answer is (a) {1,2,3,2,1} Best explanation: Given x1(N)=x2(n)={1,1,1} By calculating the Fourier TRANSFORM of the above TWO signals, we get X1(ω)= X2(ω)=1+ e^jω + e^-jω = 1+2cosω From the convolution PROPERTY of Fourier transform we have, X(ω)= X1(ω). X2(ω)=(1+2cosω)^2=3+4cosω+2cos2ω By applying the inverse Fourier transform of the above signal, we get x1(n)*x2(n)={1,2,3,2,1} |
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