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What is the use of vestigial sideband?
Vestigial sideband (VSB) is a type of amplitude modulation ( AM ) technique (sometimes called VSB-AM ) that encodes data by varying the amplitude of a single carrier frequency .
Why is SSB not used for photo signal transmission?
When carrier is shifted to bandpass, this one sided bandwidth becomes 9 MHz. This is nearly ten times as large as the total bandwidth occupied by all the channels of the AM radio. Use of SSB modulation would cut this in half but SSB is not used for video signals because of the complexity of the SSB receivers.
What do you mean by vestigial sideband transmission?
Definition: Vestigial Sideband (VSB) modulation is a modulation technique which allows transmission of one sideband in addition with a part or vestige of the other. It is basically a compromise between DSB-SC and SSB modulation. VSB technique was introduced to overcome the drawbacks of SSB modulation.
Why for some specific application VSB modulation is used instead of SSB?
Communication Systems, Civilian Vestigial sideband modulation has the virtue of conserving bandwidth almost as efficiently as SSB modulation, while retaining the excellent low-frequency baseband characteristics of double-sideband modulation. Instead, a VSB filter is inserted in each receiver.
What is the bandwidth of SSB?
With SSB, channels could be spaced (usually) only 4,000 Hz apart, while offering a speech bandwidth of nominally 300 Hz to 3,400 Hz.
Why SSB transmission is preferred?
It comes in useful because the baseband video signal is wide (typically 6 MHz). To transmit this using AM would require a bandwidth of 12 MHz. To reduce the amount of spectrum used, one sideband is transmitted fully, whereas only the lower frequencies of the other are transmitted.
Is VSB better than SSB?
To overcome all these drawbacks of SSB modulation, VSB modulation is used. Hence VSB is considered as a compromise between SSB and DSB-SC. In VSB modulation : To recover the original baseband signal from the VSB signal, the VSB signal is multiplied with cos(Wc*t) and passed through an Low Pass Filter(LPF).
What is the main advantage of VSB over SSB?
The main advantage of VSB Modulation is the reduction in bandwidth is the reduction in bandwidth. It is almost as efficient as SSB. Due to allowance of transmitting a part of lower sideband, the constraint on the filters have been relaxed.
What are the applications of AM and FM?
⇒ Telemetry, radar and seismic prospecting, EEG monitoring of new-born’s etc. also use the technique of frequency modulation. ⇒ Frequency modulation can be used for the broadcasting of FM radio. This helps in larger signal to noise ratio.
What are the advantages of vestigial sideband transmission?
Advantages of VSB The main advantage of VSB modulation is the reduction in bandwidth. Due to allowance of transmitting a part of lower sideband, the constraint on the filter have been relaxed . It possesses good phase characteristics and makes the transmission of low frequency components possible .
Which is the vestigial side band of the 625 line?
This pattern of transmission of the modulated signal is known as vestigial sideband. In the 625 line system, frequencies up to 0.75 MHz in the lower sideband are fully radiated. The picture signal is seen to occupy a bandwidth of 6.75 MHz instead to 11 MHz.
Which is part of the signal is modulated in vestigial side band modulation?
The word vestige which means “apart” from which the name is derived. Vestigial Sideband Modulation or VSB Modulation is the process where a part of the signal called as vestige is modulated, along with one sideband.
Why are two guard bands used in VSB?
The transmission bandwidth of VSB modulated wave will be the total of message bandwidth and the width of vestigial sideband. Two guard bands are laid on both the sides of this VSB signal so as to avoid the interference of signals. Highly efficient. Reduction in bandwidth. Filter design is easy as high accuracy is not needed.