सिग्नल x[n] = an + 1 u[n + 1] का द्विपक्षीय z-रूपांतरण (bilateral z-transform) क्या है?

The Fourier transform of a unit impulse function δ(t) is:

The region of convergence (ROC) of the Z-transform of the signal x(n) = 2n u(n) is:

Autocorrelation of a signal measures the similarity of the signal with ____________.