DIGITAL SIGNALS (PART 1)

 ASSALAMMULAIKUM W.B.T , I would like to share with you about the informations of digital signals in   computer.

Digital Signals refers to an electrical signal that is converted into a pattern of bits. Unlike an analog signal, which is a continuous signal that contains time-varying quantities, a digital signal has a discrete value at each sampling point. The precision of the signal is determined by how many samples are recorded per unit of time. For example, the illustration below shows an analog pattern (represented as the curve) alongside a digital pattern (represented as the discrete lines.

A digital signal is easily  represented by a computer because each sample can be defined with a series of bits that are either in the state 1 (on) or 0 (off). Digital signals can be  compressed and can include additional information for error correction.

A digital signal is a physical signal that is a representation of a sequence of discrete values (a quantified discrete-time signal), for example of an arbitrary bit stream, or of digitized (sampled and analog-to-digital converted) analog signal. The term digital signal can refer to either of the following:

      1.   Any continuous-time waveform signal used in digital communication, representing a bit stream   or other sequence of discrete values

      2.   A  pulse train signal that switches between a discrete number of voltage levels or levels of light  intensity, also known as a line coded signal or baseband transmission, for example a signal found in digital electronics or in serial communications, or a pulse code modulation (PCM) representation of a digitized analog signal.

           A signal that is generated by means of a digital modulation method (digital passband transmission), to be transferred between modems, is in the first case considered as a digital signal,and in the second case as converted to an analog signal.