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Frequency Shift Keying uses the bit to affect the frequency of a carrier sinusoid.

In frequency-shift keying (FSK), the bit affects the frequency of a carrier sinusoid.

s 0 t A p T t 2 f 0 t
s 1 t A p T t 2 f 1 t

The frequencies f 0 , f 1 are usually harmonically related to the bit interval. In the depicted example, f 0 3 T and f 1 4 T . As can be seen from the transmitted signal for our example bit stream ( [link] ), the transitions at bit interval boundaries are smoother than thoseof BPSK .

This plot shows the FSK waveform for same bitstream used in the BPSK example .

To determine the bandwidth required by this signal set, we again consider the alternating bit stream. Think of it as two signalsadded together: The first comprised of the signal s 0 t , the zero signal, s 0 t , zero, etc. , and the second having the same structure but interleaved with the first and containing s 1 t ( [link] ).

The depicted decomposition of the FSK-modulated alternating bit stream into its frequency components simplifies thecalculation of its bandwidth.

Each component can be thought of as a fixed-frequency sinusoid multiplied by a square wave of period 2 T that alternates between one and zero. This baseband square wave has the same Fourier spectrum as our BPSK example, but with theaddition of the constant term c 0 . This quantity's presence changes the number of Fourier series terms required for the 90% bandwidth: Now we needonly include the zero and first harmonics to achieve it. The bandwidth thus equals, with f 0 f 1 , f 1 1 2 T f 0 1 2 T f 1 f 0 1 T . If the two frequencies are harmonics of the bit-interval duration, f 0 k 0 T and f 1 k 1 T with k 1 k 0 , the bandwidth equals k 1 k 0 1 T . If the difference between harmonic numbers is 1 , then the FSK bandwidth is smaller than the BPSK bandwidth. If the difference is 2 , the bandwidths are equal and larger differences produce a transmission bandwidthlarger than that resulting from using a BPSK signal set.

Questions & Answers

Preparation and Applications of Nanomaterial for Drug Delivery
Hafiz Reply
Application of nanotechnology in medicine
what is variations in raman spectra for nanomaterials
Jyoti Reply
I only see partial conversation and what's the question here!
Crow Reply
what about nanotechnology for water purification
RAW Reply
please someone correct me if I'm wrong but I think one can use nanoparticles, specially silver nanoparticles for water treatment.
Damian
yes that's correct
Professor
I think
Professor
what is the stm
Brian Reply
is there industrial application of fullrenes. What is the method to prepare fullrene on large scale.?
Rafiq
industrial application...? mmm I think on the medical side as drug carrier, but you should go deeper on your research, I may be wrong
Damian
How we are making nano material?
LITNING Reply
what is a peer
LITNING Reply
What is meant by 'nano scale'?
LITNING Reply
What is STMs full form?
LITNING
scanning tunneling microscope
Sahil
how nano science is used for hydrophobicity
Santosh
Do u think that Graphene and Fullrene fiber can be used to make Air Plane body structure the lightest and strongest. Rafiq
Rafiq
what is differents between GO and RGO?
Mahi
what is simplest way to understand the applications of nano robots used to detect the cancer affected cell of human body.? How this robot is carried to required site of body cell.? what will be the carrier material and how can be detected that correct delivery of drug is done Rafiq
Rafiq
if virus is killing to make ARTIFICIAL DNA OF GRAPHENE FOR KILLED THE VIRUS .THIS IS OUR ASSUMPTION
Anam
analytical skills graphene is prepared to kill any type viruses .
Anam
Any one who tell me about Preparation and application of Nanomaterial for drug Delivery
Hafiz
what is Nano technology ?
Bob Reply
write examples of Nano molecule?
Bob
The nanotechnology is as new science, to scale nanometric
brayan
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Damian
Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
Renato
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
?
Kyle
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
Adin
why?
Adin
what school?
Kyle
biomolecules are e building blocks of every organics and inorganic materials.
Joe
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
research.net
kanaga
sciencedirect big data base
Ernesto
Introduction about quantum dots in nanotechnology
Praveena Reply
hi
Loga
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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Answers please
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Source:  OpenStax, Fundamentals of electrical engineering i. OpenStax CNX. Aug 06, 2008 Download for free at http://legacy.cnx.org/content/col10040/1.9
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