Notes: Digital Communication
Cards (55)
- information formatted in human or machine readable form
- continuous valued at some interval
- discrete valued at given interval
- electric or electromagnetic representation of data
- continuous time, infinite value
- discrete time, finite value
- efficient use of bandwidth
- measure of how much information can be propagated through a communication system
- I=kBt
- C=2Blog2(M)
- must satisfied nyquist rate
- where error occurs due to approximation
- to minimize the use of bandwidth
- combines coding and modulation
- susceptible to noise
- used to obtain noise immunity
- with noise immunity
- with very high noise immunity
- combination of ask and psk
- retain the natural shape of signal which leads to difficulties in processing
- has a flat amplitude and implemented through sample and hold
- smallest possible magnitude that can be decoded by the DAC
- process where in the quantized intervals assigned to the individual PAM samples are converted into binary signals
- how efficiently a PCM code is utilized
- ramp waveform
- each digit, balanced
- flash encoders
- coder and decoder
- encode the minimum amount of speech information to reproduce a perceptible message
- speech waveforms
- determine the location of peak frequencies
- extract the most significant portions of speech
- process of compressing and expanding of signal
- analog companding used in US and Japan
- analog companding used in Europe
- approximated by staircase function and uses single bit for transmission
- delta is automatically varied in accordance to amplitude of input signal
- makes the signal suitable for transmission
- symbol rate
- speed at which bits is transmitted