modulation radio communication

Replies

• 

  hsirah5

  #-Link-Snipped-# ,
  Your question contains the answer as well...😉
  
  FM stands for frequency modulation and FM stations uses the same.. frequency modulation is used for broadcast over shorter distances but has better quality compared to AM (amplitude modulation). In AM, you can receive the same broadcast of a particular frequency (a.k.a station broadcast) throughout the state. While in FM, you receive the broadcast at the same frequency, but the program content would vary between locations (depending upon the broadcast happening at that particular city/locality's FM radio station).. E.g:- say a particular FM channel broadcasts at 90.9 frequency. The channel would be received at the same frequency at both Chennai and Coimbatore but the content would be different as they transmitted separately by the stations in the respective city..
  
  Thus FM gives short range broadcast with better quality while AM gives you longer distance broadcast between states/cities.
  
  Hope this answers your question...😎
• 

  pratap singh, upendra

  so do you mean to say that same radio communication can be amplitude modulated as well as frequency modulated depending upon the range and quality of broadcast?
• 

  da_joker

  in Radio communication i think they uses both type of modulation for there operation. you must have heard of FM radio, it uses frequency modulation. AM modulation is mostly used in cases of long distance coverage.....
• 

  akash.kasina

  The difference between AM and FM is the modulation process implemented on the message/modulating signal.😏
  AM frequency range is of Medium frequency range(300kHz-3mHz),while FM is transmitted in Very High Frequency range(30mHz-300mHz),so as 'wavelength is the inverse of frequency',the wave with higher frequency travels lesser distance compared to that of lower frequency' may that's the reason why Am with lower frequency range,able to travel longer distances.😁
• 

  Sindhu Chowdary

  QAM(quadrature amplitude modulation),a combination of both amplitude and phase modulation is most widely used in radio communications..............it is used now a days because it has its advantages over other modulation techniques.........
  one of the advantage is.....Quadrature amplitude modulation, QAM, when used for digital transmission for radio communications applications is able to carry higher data rates than ordinary amplitude modulated schemes and phase modulated schemes.
• 

  akash.kasina

  gwendollen

  QAM(quadrature amplitude modulation),a combination of both amplitude and phase modulation is most widely used in radio communications..............it is used now a days because it has its advantages over other modulation techniques.........
  one of the advantage is.....Quadrature amplitude modulation, QAM, when used for digital transmission for radio communications applications is able to carry higher data rates than ordinary amplitude modulated schemes and phase modulated schemes.

  can you explain how the wave is Quadrature modulated,...like in AM the amplitude of carrier is super imposed by the modulating signal ,resulting in the variation in amplitude of the carrier according to the message amplitude
• 

  Sindhu Chowdary

  akash.kasina

  can you explain how the wave is Quadrature modulated,...like in AM the amplitude of carrier is super imposed by the modulating signal ,resulting in the variation in amplitude of the carrier according to the message amplitude

  QAM is nothing but amplitude modulating two signals with two different carriers with 90degrees phase shift........
  (in detail)------first take the signal to be transmitted.....let it has a signal rate of 'r'...now spllit the signal into two such that the siganl rate of the individual part becomes r/2........now both are amplitude modulated simply with a two carriers which are 90degrees phase shifted to other.....at the end combine those two parts...........here the carriers have 90 degres phase shift and the signals are ampliyude modulated thus it is said to be the combination of both the am and pm...........
  hence the bandwidth is reduced as the signalling rate is reduced..........that is in the same bandwidth more info is transmitted using this system.............
  i hope u got your answer...........got nay doubts in this feel free to ask😉