Analog and Data Flashcards
What is information?
Knowledge we want to record or transmit
What is a signal?
some means to record or transmit data or information
What are examples of signals?
voltage, current, handwritten note
What are the 2 types of Information?
- Inherently continuous
- Inherently discrete
What does inherently continuous refer to?
infinitely many values
What does inherently discrete refer to?
a finite number of values in any range
What are examples of inherently continuous?
- mass
- temperature
- most other physical quantities
- blood pressure
What are examples of inherently discrete?
- days in a week
- current study term
- names of the cities
- number of steps walked
What are the 2 main ways to represent information?
- Analog data
- Digital data
What kind of representation is analog data?
continuous representation
What kind of representation is continuous data?
discrete representation using a finite number of digits or symbols
What are examples of analog data?
thermometer
What are examples of discrete data?
digital clocks, speakers
What are the 2 methods for converting analog to digital data?
- Sampling (discretization)
- Quantization (truncation)
What does sampling do?
converts continuous variations to discrete snapshots
What does quantization do?
converts an infinite range of values to a finite one
What is an example of going from analog data to digital data?
- digitalization of video by using the still frames and dividing the picture into pixels
What is the Nyquist-Shannon sampling theorem?
The sampling rate must be at least >2x the original frequency component of the signal
What are the 2 ways we can prevent information from being lost when we convert from analog to digital?
- Nyquist-Shannon sampling theorem
- Quantization error models
What is the Quantization error models?
represent the difference between an original analog signal and its quantized digital representation
What is the basic representation for digital data?
binary digit using the symbol “b”
One bit holds a valve of what?
0 or 1
How many bits are in a byte?
8
Does DVD use decimal or binary systems?
decimal
Does CD use decimal or binary systems?
binary
Do computers work well with analog data?
No, they use digital data by breaking it down into discrete samples and then quantizing the values to approximate numbers
What are some benefits of digital signal transmissions and storage?
- Digital signals have only a high or low state (0,1)
- Analog has continuous values which will fluctuate in ranges
What is the transmission medium?
The level of the signal fluctuation will be due to the noise produced by external effects
True or False
FOR ANALOG DATA:
Degradation of analog signals is permanent; there is no way to determine if the distortions were present beforehand
True
True or False
FOR DIGITAL DATA:
If the distortion is small enough, it can completely regenerate the signal and regain in original shape
True
What are the benefits of digital storage and compression?
Both analog and digital data can be recorded
- Digital copies are always completely identical to the original
- Error-detection and correction codes exist for digital data
- Compression (data redundancy removal) is much easier with mathematical algorithms that work with discrete values
True or False
Digital data is easier to produce, transmit, can be regenerated and is easier to store and compress
True
