Let us consider the frequency-division multiplexing of discrete-time signals i = 0, 1,...

Let us consider the frequency-division multiplexing of discrete-time signals i = 0, 1, 2, 3. Furthermore, each potentially occupies the entire frequency band (—π < ω < π). The sinusoidal modulation of upsampled versions of each of these signals may be carried out by using either double-sideband techniques or single-sideband techniques.