fsk modulation demodulation essay

1 . 1 SUMMARY:

2 . one particular BLOCK DIAGRAM:

Fig installment payments on your 1 Stop diagram for FSK modulation and de-modulation

2 . 2 . 1 PIN DIAGRAM- IC 565:

Fig 2 . a couple of Pin diagram for IC 565

installment payments on your 2 . 2 PIN PICTURE -IC 5iphon scam:

Fig 2 . 3 Flag diagram to get IC 5iphon scam

3. you DESIGN CALCULATION:

3. 1 . one particular FSK MODULATOR:

ON time TH=0. 693RBC

OFF time TL=0. 693(RA+RB)C

Total period T=TH+TL=0. 693(RA+2RB)C

1

f1= “”””””””” ‘ (1)

zero. 69(RA+2RB) C1

1

f2= “””””””””””” ‘(2)

0. 69(RA+2RB) C 1C2

“”””

C1+C2

Duty pattern D=ON time/Total time=(RB)/(RA+2RB)=0. several

RB= 0. 3RA+0. 6RB

RB=0. 75RA

Permit f1= 1050 Hz, f2= 1250 Hertz, C1=0.

01μf

By (1)

1

1050 = “””””””””””

0. 69(RA+2*0. 75RA) 0. 01μf

1

=”””””””””””

0. 69*2. 5RA*0. 01μf

RA=55. 2KΩ

RB=0. 75RA

RB=41. 4KΩ

From (2)

1

1250 = “”””””””””””””””

0. 69(55. 2KΩ+2(41. 4KΩ)) 0. 01μf*C2

“””””-

0. 01μf+C2

zero. 01μf+C2 C2 = “”””””””””””

zero. 69(138KΩ)1250*0. 01μf

0. 01μf+C2 C2 = “””””

1 . nineteen

1 . 19C2 ” C2 = zero. 01μf

0. 19C2 = 0. 01μf

C2 sama dengan 52. 63 nf

3. 1 . 2 FSK DEMODULATOR:

Upper cut off frequency of RC step ladder circuit fH=1/(2Ï€RC)

Presume R2=R3=R4=R

C2=C3=C4=C

fH=(key in frequency+2 optimum frequency)/2

=(150+2(1250))/2=1325Hz

Permit C=0. 02μf then R=1/(2πCfH)=1/(2π*1325Hz*0. 02μf )=7K Ω f0=0. 3/(R1C1)

f0=(f1+f2)/2=(1050+1250)/2=1150Hz

Let C1=0. 01μf

R1=0. 3/(1150*0. 01μf)=26K Ω

flock=8f0/10=(8*1150)/10=920Hz

fcapture should be less than flock.

Choose fcapture =400Hz

fcapture =(1/2π)(2π*flock)/(R0C0)

R0=internal resistance=3. 6K Ω

C0=(2πflock)/( R0)=920/(2π (400)2*3. 6K Ω)=254nf

4. you CIRCUIT DIAGRAM:

4. 1 . one particular MODULATOR:

Fig 4. 1 Circuit diagram for FSK modulation

four. 1 . two DE-MODULATOR:

Fig 4. 2 Circuit plan for FSK de-modulation

your five. 1 WORKING PRINCIPLE:

6th. 1 OUTCOME

Fig 6. 1 Output for FSK modulation and de-modulation

six. 2 STATEMENT:

INPUT:

Extravagance = V

ON time TH sama dengan ms

OFF time TL= ms

Consistency f sama dengan Hz

FSK MODULATOR:

For great half pattern

Exuberance = Sixth is v

In time TH sama dengan ms

OFF time TL= ms

Regularity f = Hz

For negative 1 / 2 cycle

Amplitude sama dengan V

ON time A = ms

OFF time TL= ms

Frequency farreneheit = Hz

FSK DEMODULATOR:

Amplitude = Versus

ON time TH = ms

OFF period TL= ms

Consistency f sama dengan Hz

six. 1 SUMMARY:

7. 2 APPLICATIONS:

7. 2 . 1 USED IN THE GSM MOBILE NORMAL

Minimal frequency-shift keying or minimum-shift keying (MSK) is a specifically spectrally successful form of coherent FSK. In MSK thedifference between the higher and lower frequency is definitely identical to half the bit rate. Therefore, the waveforms used to represent a 0 and a 1 bit change by accurately half a transporter period. This is the smallest FSK modulation index that can be selected such that the waveforms for 0 and 1 are orthogonal. A variant of MSK referred to as GMSK is employed in the GSM mobile phone common. 7. installment payments on your 2 EMPLOYED IN CALLER IDENTITY

FSK is often used in Harasser ID and remote metering applications. Sound frequency-shift keying (AFSK) is actually a modulation technique by which digital data is represented by changes in the regularity (pitch) of your audio sculpt, yielding an encoded sign suitable for transmission via car radio or mobile phone. Normally, the transmitted music alternates among two shades: one, the “mark, signifies a binary one; the other, the “space, symbolizes a binary zero. several. 2 . several USED TO MODULATE AN RF CARRIER INTENDED FOR TRANSMISSION

AFSK differs coming from regular frequency-shift keying in performing the modulation in baseband eq. In a radio station applications, the AFSK-modulated transmission normally will be used to modulate an RF carrier (using a conventional strategy, such as WAS or FM) for transmitting.

7. three or more ADVANTAGES:

AFSK is not always used for high-speed data communications, since it is far less efficient in both electric power and bandwidth than most other modulation modes. In addition to its simpleness, however , AFSK has the benefit that encoded signals can pass through AC-coupled links, which includes most gear originally built to carry music or conversation.

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