Study of Transform domain properties and its use 
References
Books
-Discrete-Time Signal Processing, A. V. Oppenheim and R. W. Schafer, Englewood Cliffs, NJ: Prentice Hall, 1989. -2.C. E. Shannon, "Communication in the presence of noise," Proc. Institute of Radio Engineers, vol. 37, no. 1, pp. 10-21, Jan 1949. -3.H. Nyquist, "Certain topics in telegraph transmission theory," Trans. AIEE, vol. 47, pp. 617-644, Apr 1928.