Question

Explain the effect of noise on digital data communication system

Answer 1

Intermodulation (IM) effects result when two or more signals pass through a nonlinear device or medium and interact with each other in ways that produce additional signals, such as harmonics and subharmonics of input signal frequencies. These resulting IM components may be inside or outside the frequency band of interest for a particular device; it is only when they are inside the band of interest that IM effects become IM noise.

IM noise is a significant concern in radio communications, including cellular telephony and data networks. Component manufacturers test for it -- it can result from either design characteristics of a system, or from manufacturing defects. But it can become an issue post-manufacture due to damage to a component, so field engineers need to watch for it, too.