Signals and Systems: Intro Flashcards
What domains can a signal be in?
Time or frequency(domain or spectrum)
What is antenna theory
to transmit efficiently we need an antenna which lambda/4
Why do we transmit at different frequencies
To avoid interference
What is time domain multiplexing
when a time is allotted to transmit, this prevents interference from transmitting at the same time
what forms of multiplexing are there
- time multiplexing
- frequency multiplexing
- code multiplexing
what is frequency domain multiplexing
transmitting at an allotted frequency band
What are the benefits of transmitting with high frequency
higher communication capacity and quality
what are the disadvantages of high frequency transmissions
- travels less
- costs more
what are the advantages of low frequency transmissions
- costs less
- transmits much furthers
what are the disadvnatages of low frequency transmissions
- less communication capacity
- lower quality
what equation relations frequency to wavelength
lambda=c/f aka speed of sound/frequency
- lambda = wavelength
- c = 3x10^8 speed of light
what is modulation
process of converting a low frequency to high frequency signal on to a frequency carrier and vice versea
what 4 forms of modulation are there
- amplitude
- phase
- frequency
- digital
hat is demodulation
converts back from modulation. takes away the high frequency ‘carrier’ and leaves the message
