while demodulating the modulated signal using coherent detection at the receiver end we need to generate the same carrier which is a very difficult ,it makes the receiver costlier and complex because the signal get distorted during the transmission process so generating the same carrier is quite impossible . if we are required to transmit the message to a large number of receivers than it will become very complex and costly.
secondly when we modulate and send a pilot carrier it become possible to detect the signal by envelope detection method which requires very less circuitry and is very cheap. provided the sum of maximum amplitude of carrier and the message signal must be greater than zero so that the envelope gets a lift up..
the disadvantage of this scheme is that the higher transmission power is required...
For transmission through a radiowave.
yes for transmission of the signal to take place smoothly,digital tranmission needs to be modulated over a carrier
You need modulation signal(carrier) which is a required signal in order to make envelope of time domained signal(target signal). The modulating signal is imposed on modulation signal.This creates envelope of waveform which is modulated(desired) signal. Now, the desired signals uper and lower sideband of signal strictly depends on modulation signal's bandwidth. Max. peak of that signal is uper sideband and min. peak is lower sideband for this modulated signal.
With full double sideband AM the bandwidth of the modulated signal is twice that of the baseband information signal. With suppressed carrier single sideband AM the bandwidth of the modulated signal is identical to that of the baseband information signal. With vestigial sideband AM the bandwidth of the modulated signal is somewhere between the above two cases, depending on how much of the vestigial sideband is included.
The intelligence signal is in the AM envelope.In AM modulation, the carrier is amplitude modulated by the signal. This signal appears as the envelope of the carrier. You can demodulate it by following the peaks on each cycle of the carrier. You can either follow the positive peaks or the negative peaks - it does not matter if the original modulation is symmetrical.
carrier signal- use for the purpose of conveying information. modulating signal- causes variations in some characteristics of carrier signal. modulated signal - carrier signal after altration in its characteristics is called modulated signal. example- if you want to see an object (suppose it is an modulating signal),you need light(light is carrier signal) and when light will reflect on object you will be able to see if (that is modulated signal)
It gives frequency modulated signal
For transmission through a radiowave.
No, the carrier signal is not present at the output of double side band suppressed carrier. That is what suppressed carrier means. However, the receiver has enough information to regenerate the carrier if need be. The advantage of suppressed carrier mode is that more power can be deployed to the signal-carrying portion of the modulated carrier.
yes for transmission of the signal to take place smoothly,digital tranmission needs to be modulated over a carrier
because demodulated FM is an audio signal, which the frequency is much smaller that is why it can be transmitted alone. It need carrier which has large frequency. Modulated signal is an audio signal + carrier that is why the amplitude is higher.
low level amplitude modulation occurs when the carrier signal is first modulated and then amplified,whereas in high level modulation,the carrier signal is first amplified and then is modulated.
A base signal that is modulated with the information being transmitted.
You need modulation signal(carrier) which is a required signal in order to make envelope of time domained signal(target signal). The modulating signal is imposed on modulation signal.This creates envelope of waveform which is modulated(desired) signal. Now, the desired signals uper and lower sideband of signal strictly depends on modulation signal's bandwidth. Max. peak of that signal is uper sideband and min. peak is lower sideband for this modulated signal.
Modulation is where an electronic signal (base) is combined with another electronic signal (carrier).The base could be audio, video or digital. The carrier is the frequency that a receiver (radio or television) is tuned to.The modulated wave is the result of this combination.
Frequency Modulation must have a carrier whereby the frequency can be modulated by the signal
Carrier Wave: A carrier wave is a high-frequency electromagnetic wave that is used as the "carrier" or the base signal in a modulation process. It is typically a pure sine wave with a constant frequency and amplitude. The carrier wave by itself does not carry any information; it serves as a vehicle to carry the information from one location to another. In AM and FM radio broadcasting, the carrier wave is the primary signal transmitted by the radio station. Modulated Wave: A modulated wave is the result of combining the carrier wave with an information signal, such as an audio signal or data. Modulation is the process of varying the characteristics of the carrier wave (either its amplitude or frequency) in accordance with the information signal. There are two common types of modulation: Amplitude Modulation (AM) and Frequency Modulation (FM). In AM, the amplitude of the carrier wave is varied in proportion to the amplitude of the information signal. This variation encodes the information onto the carrier wave. In FM, the frequency of the carrier wave is varied in proportion to the amplitude of the information signal. This variation encodes the information onto the carrier wave. The modulated wave contains the information that needs to be transmitted, and it can be demodulated at the receiving end to retrieve the original information.