Frequency modulation is not used for long distance transmission because it has the problem of limited band width.
The Role of modulation in signal transmission varies because of what type of signal should be modulated.Then how long it should be travel in air.All these points are considered, when we go before modulation.Suppose we are transmitting vedio signal means it should be only Amplitude Modulated signal.If we transmitting audio signal means it should be Frequency Modulated Signals.So the Role of the modulation is varies in signal transmission.
Need for modulation: 1. Length of the antenna for a transmitter is inversly proportional to the frequency of the signal to be transmitted. So we try shift the frequency of the singal for the transmission to higher frequencies. 2. Every transmission of signal in a bandwidth is assigned with a particular frequency which is attained by modulating the signal with the carrier frequency. Different modulation techniques are implemented according to the requirements and compatibilities
Amplitude modulation of a carrier results in a transmitted signal consisting of the carrier, plus an 'upper sideband' and a 'lower sideband', spaced above and below the carrier frequency by the frequency of the modulation.The bandwidth of the whole signal is double the modulation frequency. Also, the power in the carrier is constant, and power must be added in order to radiate the sidebands.All the receiver needs in order to extract the information from the signal is one complete sideband, and knowledge of the frequency and phase of the carrier. Economically speaking, the carrier is wasted power, and the other sideband is wasted power andwasted spectrum.If you can filter away one of the sidebands before transmission, then you save half of the occupied spectrum, and the receiver has everything it needs to decode the signal. If you can also filter away the carrier ... or at least knock it way down ... before transmission, you can save a lot of power and use it for the remaining sideband, which extends your range for a given amount of power. The receiver still has everything it needs, as long as it can pick up a sniff of carrier ... enough to derive the carrier frequency and phase.This mode is known as "Single Sideband Suppressed Carrier". It's exactly how the video portion of standard NTSC analog TV was transmitted, throughout all of human history until June 2009.
AM has a frequency range of 531 kHz to 1602 kHz and on the other hand FM has a frequency range between 8705 MHz to 108 MHz. If we talk about the bandwidth of AM then it is 1071 KHz and bandwidth of FM is 20.5 MHz.According to the bandwidth FM should be used for long distance transmission but it is not used for long distance but AM is used fir long distance transmissions. the answer is here.Long distance transmissions are also decided by the Spectrum of the Signal in frequency domain by doing the Fouriertransform of the Signal.If we draw the Spectrum of AM waves the we find that their is a main loop in the central part of the spectrum with a high frequency and on the left and right side of this loop their are side loop which are very smaller then the main loop. In FM information can be recover from the main loop only not from the side loops. On the other hand in AM waves all the loops in spectrum is of same size and information can be recover from all the loops.That is why AM is used for long distance transmission.Thnx -Vipin Jasoria
It should work... just as long as a receiver is nearby with the same frequencies. Any radio will transmit anywhere. it's just that nobody will hear it unless they are on the same frequency and within hearing range.
modulation is necessary for transmitting low frequency signal to long range with desired qualitative information
The Role of modulation in signal transmission varies because of what type of signal should be modulated.Then how long it should be travel in air.All these points are considered, when we go before modulation.Suppose we are transmitting vedio signal means it should be only Amplitude Modulated signal.If we transmitting audio signal means it should be Frequency Modulated Signals.So the Role of the modulation is varies in signal transmission.
Need for modulation: 1. Length of the antenna for a transmitter is inversly proportional to the frequency of the signal to be transmitted. So we try shift the frequency of the singal for the transmission to higher frequencies. 2. Every transmission of signal in a bandwidth is assigned with a particular frequency which is attained by modulating the signal with the carrier frequency. Different modulation techniques are implemented according to the requirements and compatibilities
AM (Amplitude Modulation) has a smaller bandwidth and can have more stations available in any frequency range. AM is cheaper and can be transmitted over long distances. FM (Frequency Modulation) signals are prone to interference due to physical obstructions. The better sound quality is due to a much higher bandwidth, using FM.
Modulation is any of several means of encoding an information carrying signal onto a carrier of fixed frequency. The purpose is to allow the information to be transported long distances.
Analog radio uses either amplitude modulation (AM) or frequency modulation (FM) to carry an audio signal. AM signals can be received at greater distances than FM but they suffer from interference from other stations and a wide range of electro-magnetic sources. FM signals offer better quality with less interference than is typically found with an AM signal. The transmission range is far smaller than AM. For a wide geographic coverage, multiple transmitters are needed although the limited range also makes FM an ideal medium for local stations where long range is undesirable.
Aplitude ModulationAn AM transmitter is a Amplitude Modulated transmitter where the amplitude of the Radio Frequency signal is modulated, usually used in the lower frequency bands where the frequency is to low for Frequency Modulation (FM), it was the first type of modulation used in radio communication FM was developed in the late 1950's and is not sensitive to static interference as AM AnswerAM is Amplitude Modulation that is the RF signals amplitude is modulated with the audio signal. this modulation is done because the audio signal being of low frequency cannot be transmitted to longer distance so the audio signal is amplitude modulated with RF signal and then transmitted into the air
This refers to the concept of modulation, where a carrier wave's strength or characteristics are modified to convey information. Modulation techniques include amplitude modulation (AM), frequency modulation (FM), and phase modulation (PM). These techniques are commonly used in telecommunications for transmitting signals over long distances.
modulating signal is the low frequency signal .so we cant transmit for a long distance.so we go for modulating the signal either by modulating the amplitude or frequency or phase of the signal.
An electric current that is varied to represent information is called a modulated current. This modulation can take various forms, such as amplitude modulation (AM), frequency modulation (FM), or pulse modulation, and is commonly used in telecommunications to transmit data over long distances efficiently.
Modulation is the process of varying a carrier signal's properties, such as amplitude, frequency, or phase, to encode information for transmission. In communication systems, modulation is used to efficiently transmit data over long distances by converting the information into a form that can be carried by the carrier signal. Two examples of how modulation is utilized in modern technology are: In Wi-Fi technology, modulation techniques like Quadrature Amplitude Modulation (QAM) are used to encode digital data into radio waves for wireless communication between devices. In digital television broadcasting, modulation methods such as Vestigial Sideband Modulation (VSB) are employed to transmit audio and video signals over the airwaves for high-quality TV reception.
encoding means to encode the data generally it uses for security purposes, we encode the data by using some mathematics operations so that no other could get the information. in modulation we also change the input but it is used for the send the signals to a long way. the week frequency signals can not travel to the long way so we superimpose the week frequency signals to the high frequency signals so that it could reach at it destination. the reverse process of encoding is decoding and the reverse process of modulation is demodulation so that we can get our data in a original form.