Major disadvantage is that telephone lines are very susceptible to variations in transmission quality that can affect amplitude
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This is hard to explain. AM means amplitude modulation, while ASK is amplitude-shift keying. AM is usually analog as it is modulated based on the strength of the signal, though you can use it to send a digital signal. ASK represents digital data as variations in the amplitude of a carrier wave. Any digital modulation technique will represent the data using a finite number of different signals. While AM is used mostly for radio and television, ASK is used for telegraph signals, transmission across telecommunications equipment, and fiber optics.
Block digram of fsk is the representation of fsk modulation
It might be helpful to have a working definition of modulation before making a statement as to why it is needed. In fact, with an understanding of what modulation is, it will be obvious why it is included in electronic communications.Modulation is the "message" or the "intelligence" that is impressed on a radio frequency (RF) carrier. When we transmit a signal, we generate a carrier frequency, and then we modulate it. We "add" the message or the information we wish to transmit by modulating the carrier in some way. There are at least a dozen different modulation schemes ranging from simple to real head scratchers. They either modify the amplitude, the frequency or the phase of the carrier. Let's look at a few.The simplest modulation technique is taking the transmitted signal and turning it on and off. It is "keyed" to send a series of pulses. Morse code uses on-off keying. In this method of modulation, no modification of the RF carrier signal itself is made. It is simply switched on and off. (It could be looked at as amplitude modulation with the carrier either at zero amplitude or at "maximum" amplitude with nothing in between.) A series of pulses can be transmitted. With Morse code, a short "on" period will send a dot or "dit" out. If we extend the "on" period a bit, we can send a dash or "dah" out. Nothing real sophisticated here, but basic and effective communication. There are obvious limits to how fast information can be transmitted with this modulation scheme. (But don't tell the hams who still use it!)Most of us are familiar with AM radio. AM is amplitude modulation. The amplitude of the RF carrier is modified to modulate it. The amplitude of the modulating signal will determine the amount that the amplitude of the carrier is changed. (The volume of the modulation determines how much the amplitude of the carrier is changed. The frequency of the modulating signal determines the rate of change of the amplitude of the carrier. (The frequency of the modulation determines how fast the amplitude of the carrier is changed.). The frequency of the carrier is held constant through all this.How about FM? In frequency modulation, the amplitude of the carrier is constant. It's left alone. But the frequency of the RF carrier is changed. It is swung above and below where it sits (it's assigned center frequency) at a rate proportional to the frequency of the modulating signal, and at an amount proportional to the amplitude of the modulating signal. In FM single sideband, the carrier frequency and the frequencies above the carrier are transmitted and the frequencies below the carrier are suppressed (upper sideband transmission). Or the frequencies below the carrier are transmitted with the carrier and the upper frequencies are suppressed (lower sideband transmission). In conventional television, the video signal is single sideband, suppressed carrier. It's like "regular" upper sideband transmission except the carrier signal is suppressed. Sideband transmission "saves" space on the RF spectrum. And it works because we really don't need "all" of the FM signal to demodulate the signal at the receiver.Other forms of modulation become more complex. CDMA (code division multiple access), TDMA (time division multiple access) and other methods are used in cell phones to modulate the carrier so the digital data stream can be impressed on the carrier.Modulation is the addition of intelligence to a carrier signal. It's the message. Modulation is necessary because the point of communication is getting the message through.A Simple answer:Simply this... Any communications medium: e.g. Free space - radio waves, Air - Sound waves or radio waves, Optical Fibre - Light, Copper Wires Electrical Anergy (with frequency limits of the copper wire construction) is made for a certain type of signal. But if the signal we want to send is not compatible with the medium, then it does not travel well.Modulation changes the information we want to send from it's original form, into one that is more compatable with the medium we are trying to use.For example, your computer speaks digital over a TCP/IP LAN which requires CAT 5 or better rated cables,, but to connect to your internet service provider (ISP), you need to send the signal over the wires of the telephone company (made for voice tones). To make this connection, and ADSL modem (modulator/demodulator) is used to convert the data into audio tones, which pass over the telephone line, and at the far end are converted back to digital to join the service providers network. in the reverse direct the ISP does the same, and the signals are de-modulated, back to data for your network.Or in simple terms, Its about best use of the medium. Everything else is just a away of doing it. And there are a lot of possible ways to choose.
Like in modems, you make digital zeros one frequency and digital ones another frequency.
A toaster can be either of :A small appliance for the browning of bread into toast. Electricity is converted to heat in a series of wires which creates heat to partially char the bread. AN adjustable thermostat in the system releases a catch to pop the toasted bread up when a certain temperature is reached.An electronic/software system (Video Toaster) for the editing and production of standard-definition and high-definition video in NTSC, PAL, and resolution independent formats on personal computers running a Windows operating system. It allows video switching, chroma keying, character generation, animation, and image manipulation.
micxingthe between the phasr and frepaancy shift keying
amplitude shift keying is a form of modulation in digital signal that variation in the amplitude of carrier wave. application of ask: *used mainly for radio frequencies
The most fundamental difference, I would say, is that Amplitude Modulation (AM) is a kind of Analog Modulation Technique (the modulation is applied continuously in response to the analog information signal) where Amplitude Shift Keying is a type of Digital Modulation Technique ( an analog carrier signal is modulated by a discrete signal, digital modulation methods can be considered as digital-to-analog conversion, and the corresponding demodulation or detection as analog-to-digital conversion. The changes in the carrier signal are chosen from a finite number of M alternative symbols).
Form of modulation that represents digital data as variations in the amplitude of a carrier wave Follow this link to get exact idea of Amplitude Shift Keying (ASK) http://www.circuitsgallery.com/2012/05/binary-amplitude-shift-keying-bask-or.html
This is hard to explain. AM means amplitude modulation, while ASK is amplitude-shift keying. AM is usually analog as it is modulated based on the strength of the signal, though you can use it to send a digital signal. ASK represents digital data as variations in the amplitude of a carrier wave. Any digital modulation technique will represent the data using a finite number of different signals. While AM is used mostly for radio and television, ASK is used for telegraph signals, transmission across telecommunications equipment, and fiber optics.
Amplitude modulation (AM) is a technique used in electronic communication, most commonly for transmitting information via a http://wiki.answers.com/wiki/Radio http://wiki.answers.com/wiki/Carrier_wave. AM works by varying the strength of the transmitted signal in relation to the information being sent. Angle modulation is a class of http://wiki.answers.com/wiki/Analog_signal http://wiki.answers.com/wiki/Modulation. These techniques are based on altering the http://wiki.answers.com/wiki/Angle or http://wiki.answers.com/wiki/Phase_%28waves%29 of a http://wiki.answers.com/wiki/Sinusoidal http://wiki.answers.com/wiki/Carrier_wave to http://wiki.answers.com/wiki/Transmission_%28telecommunications%29 data. The two main types of angle modulation are: http://wiki.answers.com/wiki/Frequency_modulation (FM) in which the http://wiki.answers.com/wiki/Frequency is varied, http://wiki.answers.com/wiki/Phase_modulation (PM) in which the http://wiki.answers.com/wiki/Phase_%28waves%29 is varied.
Amplitude shift keying (ASK) is simple to implement and requires less bandwidth compared to other modulation techniques. It is also less susceptible to noise interference, making it suitable for applications where signal clarity is important. Additionally, ASK is energy efficient as it allows for power conservation by varying amplitude levels.
It uses GFSK (Gaussian Frequency Shift Keying) modulation technique.
Amplitude shift keying changes the height/power of the transmitted signal without altering the frequency. Frequency shift keying changes the frequency of the transmission without altering the height/power of the transmitted signal. Morse code is an example of amplitude keying where the amplitude is 0 or 100%. RTTY teleprinter uses FSK with two frequencies and the codes that represent text characters are sent with patterns of the two frequencies.
Block digram of fsk is the representation of fsk modulation
Both are digital modulation types for radio, transmitting data as two states usually. Amplitude shift keying varies the amplitude of the carrier, and often is used to switch the carrier on or off for the two states. Frequency shift keying varies the frequency of the carrier, so it is one of two distinct frequencies. These can be seen as digital versions of AM and FM.With amplitude shift keying the detector needs to distinguish between the two levels, which can vary widely due to propagation. Some sort of gain control or automatic threshold adjustment is needed, and noise bursts can be misinterpreted as data. This method tends to be simpler to implement, but less reliable than other modulation types (more prone to interference).Frequency shift keying is more or less constant amplitude so the interference (which is mostly AM in nature) is better suppressed. Frequency stability can be an issue with narrow band UHF radios.---ASKAudio Shift Keying - Digital signals are sent by modulating a carrier using an two or more tone audio tone. This is generally used for single sideband transmissions, but since it is an audio signal it can be used on FM/PM/AM.FSKFrequency Shift keying - Digital signals are sent by changing the frequency of an amplitude UN-modulated signal and decoding it using a side-tone receiver to reproduce the tones. FSK can be sent by any mode which has a carrier.
Frequency shift keying in digital communication and Frequency modulation in analog communication..........