Continue to Site

Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

What is a signal carrier?

Status
Not open for further replies.

zahrein

Full Member level 2
Joined
May 28, 2004
Messages
144
Helped
1
Reputation
2
Reaction score
1
Trophy points
1,298
Activity points
1,454
What is a carrier?

What is a carrier?
 

Re: What is a carrier?

Ok a carrier is a guy that mobilises INFORMATION or even a VIRUS !..
but i assume that you mean a SIGNAL CARRIER .. well is the same is a SUPPORT of a SIGNAL carrying information .when you SHOUT ..
"HELLO".. well the INFORTMATION are the PHONEMS of in a intelligeble language .But the carrier here is the air . The AIR BECOMES MODULATED
by pressure waves and thus it propagates!
The same PRINCIPLE is used with other types of energy .. a beam of light or IR can be modulated .. to send music or other type of information .The CARRIER here is light or IR .. but ligh by ITSELF has no INFORMATION .. it NEEDS TO BE MODULATED with with signal that contains that INFORMATION /Now the FIELD where you will hear a lot about this three WORDS . CARRIER , MODULATION ,SIGNAL is IN RF TELECOMUNICATIONS
The typical way to comunicate is
1) GENERATE A CARRIER SIGNAL
2) MODULATE the carrier with ANOTHER SIGNAL ( voice or data)
3) TRANSNMIT the mixture of BOTH SIGNAL ABOVE

in the reception process you do :
1) Recover as much of the TRANSMITTED mixture of signals
2) FILTER and get RID OF THE CARRIER (it has no INFORTMATION)
3) GET PURE INFORMATION from the DEMODULATED SIGNAL

as you see the CARRIER is NECESSARY just like an envellope is necessary to send a letter .. but ultimatly the letter is what you want !
 

Re: What is a carrier?

Yep. A carrier signal is used to piggyback the message signal. They are at a much higher frequency than the message signal. Imagine your message signal being a series of '1's and '0's with '1's. '0's are represented by a ground voltage. When you multiply the carrier and message signals, '1's are represented by a multiple of the carrier frequency, and '0's are represented by ground. That's one form of modulation.
Under the frequency domain, you would see the spectrum of the message signal up-shifted by the frequency of the carrier. When you envision the concept of many signals occupying a limited bandwidth, you will come to appreciate the use of a carrier signal.
 

Re: What is a carrier?

Hi,
a carrier signal is a frequency in a communications channel modulated to carry analog or digital signal information. For example, an FM radio transmitter modulates the frequency of a carrier signal and the receiver processes the carrier signal to extract the analog information. An AM radio transmitter modulates the amplitude of a carrier signal.

regards
taring
 

Re: What is a carrier?

in the field of communication,if we want to transmit our voice signal or digital data in the form of electric signal,through electromagnetic wave medium,it is impossible because at low frequencies(upto 30khz) electromagnetic waves can not radiate from conductor(antenna) ,that to we need large power to radiate and huge antenna's,due to theoritical requirement of antenna length is 1/4 wavelength of the signal,
at high frequencies em radiation is high,so to transmit our signal we use a high frequency carrier called carrier,to transmit our signal along with carrier ,we modify the electrical charactaristrics of carrier such as amplitude,frequency,phase according to our instataneous signal,the process is known as modulation,
the high frequency signal is used to transmit low frequengy
voice or digital data, hence such high frequency signal is called as carrier
 

Re: What is a carrier?

A signal usually a small one in frequency that is altered (modulated) in some characteristic such as frequency, amplitude, phase, pulse width, angle etc. so that information can be transmitted and accepted at the receiver.
 

Re: What is a carrier?

Hi.
Have you seen the ligths in a discotheque, varying at the rithm of music ?
That variation of brightness is the modulation, (amplitude modulation or AM), just as the music.
The carrier is the light. The light carries the music variations to your eyes.
Miguel
 

Re: What is a carrier?

Many times the carrier will be present when the modulating signal is lost. This is because the signal has to change the voltage of the carrier by a certain amount in order for it to be later detected.
 

Re: What is a carrier?

you know for sending signals,you should use carrier waves
because signals can not be send by themselves
like cariier electromagnetic waves :eek:
 

What is a carrier?

when you try to send information througt any comunication cahnl you need anything take this information from one side to other side . A frequency carrier do this thing without a frequency carrier you can´t take a comunication ain a chanel with many disturance lke the air.
 

Status
Not open for further replies.

Similar threads

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top