Types of Conversions Cont

Conversions Types of Digital-to-Digital Encoding

Example 5.1 Š    Using B8ZS, encode the bit stream 10000000000100. Assume that the polarity of the first 1 is positive. ™   Analog-to-Digital Conversion o    We sometimes need to digitize an analog signal o    To  send  human  voice  over  a  long  distance,  we  need  to  digitize  it,  since digital signals are less prone to Noise o    This  is  called  Analog-to-Digital  Conversion  or  Digitizing  an  Analog Signal o    This type of conversion requires a reduction of  potentially infinite number of  values  in  the  analog  signal  so  that  it  can  be  converted  to  digital  bit stream with minimum loss of information.

o    CODEC Æ Coder Decoder o    Digital signal signals can take any of the forms discussed previously o    Problem is how to convert analog signal from infinite number of values to discrete no. of values without scarifying quality    Pulse Amplitude Modulation o    First step in Analog-to-Digital Conversion o    This technique takes an Analog signal, Samples it, and Generates a series series of Pulses based on the results of Sampling o    Sampling means measuring amplitudes of signal at equal intervals