Understanding Noise in Signals

Unwanted electronic signal with random frequencies and varying amplitudes added to a signal during transmission or processing.

Unwanted interference that degrades communication signals.

The origin of the unwanted electronic signals.

Noise requires a higher value to impact digital signals compared to analog signals.

Static heard on a radio while changing stations, or 'snow' on a TV screen.

Signals that change continuously, such as radio broadcasts.

Signals that use discrete, binary values to transmit information.

Undesired information signals that disrupt an intended signal.

Noise that originates from sources outside a system, which are essentially beyond human control. Examples include industrial, atmospheric, and extraterrestrial sources.

Noise from manufacturing equipment like motors, generators, and ignition systems, often in the form of transients (short bursts of energy).

Electrical disturbances in the atmosphere, often caused by lightning, that appear as static and affect signals, particularly those below 30 MHz.

Noise originating from space, including solar (from the sun) and cosmic (from stars).

Noise from the sun, which has an 11-year cycle, and frequently interferes with radio communications, especially at peak intensity.

Noise from stars outside our solar system, causing less disruption than solar noise, but is significant between 10 MHz to 1.5 GHz and in the 15-150 MHz range.

Noise originating from electronic components within a receiver, including resistors, diodes, and transistors. Although low-level, it can interfere with weak signals.

Noise caused by the random movement of electrons in a conductor due to heat.

Random noise created by thermally agitated atoms in a conductor that impede electron flow, changing apparent resistance.

Random noise containing all frequencies at random amplitudes, similar to white light containing all colors.

Filtered or band-limited noise, containing frequencies of different energy levels.

Noise produced by components like diodes and transistors, including shot, transit-time, and flicker noise.

Random noise generated by the random and non-linear flow of current carriers (e.g., electrons) moving in a device.

Noise caused when the transit time of a signal frequency equals the time a current carrier takes to move from input to output.

Noise (excess noise) caused by random resistance variations in semiconductor materials.

Noise produced by non-linear circuits when multiple signals are present, creating new signals and harmonics.

Noise issues arise when received signals have low amplitudes, but often isn't a major concern for short-distance, high-power transmissions.

A measure of the relative strengths of a signal and noise in communication systems.

Indicates a strong signal and weak noise, resulting in reliable reception.

Indicates a weak signal and strong noise, resulting in unreliable reception.

SNR calculated using the ratio of signal voltage (Vs) to noise voltage (Vn).

SNR calculated using the ratio of signal power (Ps) to noise power (Pn).

The voltage strength of the signal.

The voltage strength of the noise.

The power strength of the signal.

The power strength of the noise.

A measure of signal strength relative to noise strength, calculated by dividing signal power by noise power.

Calculated as signal power (Watts) divided by noise power (Watts).

A logarithmic unit used to express the ratio of two values, often for S/N, voltage, or power.

20 log(S/N) voltage ratio, or in other words, use the 20 log formula for the voltage part of the equation.

10 log(S/N) for the power ratio, or in simpler words, use the 10 log formula for the power part of the ratio equation.

Ratio of input signal-to-noise ratio (S/N) to output signal-to-noise ratio (S/N).

Noise factor expressed in decibels (dB).

Unwanted change in a signal's waveform, altering its shape.

Distortion alters the signal's form, while noise adds random interference.

Distortion can be used for desirable effects like musical enhancement or noise reduction in systems like Dolby.