# 49. Let X(t) be a wide sense stationary (WSS) ...

49. Let X(t) be a wide sense stationary (WSS) random process with power spectral density SX(f). If  Y(t) is the process defined as Y(t)=X(2t-1) , the power spectral density SY(f) is

(A) $S_y(f)={1\over2}S_x{({f\over2})}e^{-jxf}$

(B) $S_y(f)={1\over2}S_x{({f\over2})}e^{-jxf/2}$

(C) $S_y(f)={1\over2}S_x{({f\over2})}$

(D) $S_y(f)={1\over2}S_x{({f\over2})}e^{-j2xf}$

Hint: