ANALOG AND DIGITAL TRANSMISSION

INTRODUCTION TO ANALOG AND DIGITAL

Analog Information

Analog information is continuous and does not stop at discrete values. An example of analog information is time. It is continuous and does not stop at specific points. An analog watch may have a second-hand which does not jump from one second to the next, but continues around the watch face without

stopping.

Analog Signals

An analog signal is a continuous waveform which changes in accordance with the properties of the information being represented.

Analog Signal

Digital Information

Digital information is a set of discrete values. Time can also be represented digitally. However, digital time would be represented by a watch which jumps from one minute to the next without stopping at the seconds. In effect, such a digital watch is taking a sample of time at predefined intervals.

Digital Signals

For mobile systems, digital signals may be considered to be sets of discrete waveforms.

Digital Signal

ADVANTAGES OF USING DIGITAL

Human speech is a form of analog information. It is continuous and changes in both frequency (higher and lower pitches) and amplitude (whispering and shouting). At first, analog signals may appear to be a better medium for

carrying analog information such as speech. Analog information is continuous and if it were to be represented by discrete samples of the information (digital signal), then some information would be missing (like the seconds on the digital watch). An analog signal would not miss any values, as it too is

continuous. All signals, analog and digital, become distorted over distances.

In analog, the only solution to this is to amplify the signal. However, in doing so, the distortion is also amplified. In digital, the signal can be completely regenerated as new, without the distortion.

Regeneration of digital signal

The problem with using digital signals to transfer analog information is that some information will be missing due to the technique of taking samples. However, the more often the samples are taken, the closer the resulting digital values will be to a true representation of the analog information. Overall, if samples are taken often enough, digital signals provide a better quality for transmission of analog information than analog signals.