SlideShare a Scribd company logo
Phase Shift Keying &
π/4 -Quadrature Phase Shift
Keying
Presentation by:
Naveen Jakhar, ITS
1
Topics covered in this presentation:
 Some basic definitions & concepts of digital communication
What is Phase Shift Keying(PSK) ?
Binary Phase Shift Keying – BPSK
BPSK transmitter & receiver
Advantages & Disadvantages of BPSK
Pi/4 – QPSK
Pi/4 – QPSK transmitter & receiver
Advantages of Pi/4- QPSK
2
Some basic concepts of Digital Communication:
Information capacity: linear function of bandwidth and transmission
time i.e. 𝐼 ∝ 𝐵 × 𝑡
where I is information capacity(bits per second)
B is bandwidth (hertz)
t is transmission time (sec)
 Shannon limit for information capacity
𝐼 = 𝐵 log2(1 + 𝑆𝑁𝑅)
Where SNR is signal to noise power ratio (unit less quantity)
3
M-ary coding:
M-ary is a term derived from binary
M represents a digit that corresponds to the number of conditions,
levels, or combinations possible for a given number of binary
variables, for e.g. a digital signal with four possible conditions (voltage
levels, frequencies, phases) is an M-ary system where M = 4
Number of bits necessary to produce a given number of conditions is
expressed mathematically as 𝑁 = log2 𝑀 or 2 𝑁 = 𝑀 where N is
number of necessary bits & M is number of
conditions/combinations/levels
4
Baud and Minimum bandwidth:
Baud or symbols per second- rate of change of a signal on the
transmission medium after encoding and modulation have occurred
Baud is a unit of transmission rate, modulation rate or symbol rate
𝐵𝑎𝑢𝑑 =
1
𝑡 𝑠
where 𝑡 𝑠is time of one signalling element (seconds)
Minimum theoretical bandwidth necessary to propagate a signal is
called the minimum Nyquist bandwidth or minimum Nyquist
frequency. Thus,𝑓𝑏 = 𝐵, where 𝑓𝑏 is the bit rate in bits per second
and B is the ideal Nyquist bandwidth.
5
Baud and Minimum bandwidth: continued ….
 The relationship between bandwidth and bit rate also applies to the
opposite situation. For a given bandwidth (B), the highest theoretical
bit rate is 2B.
Using multilevel signalling, the Nyquist formula for channel capacity
is 𝑓𝑏 = 𝐵log2 𝑀 or 𝑓𝑏 = 𝐵 × 𝑁 => 𝐵 =
𝑓 𝑏
𝑁
where 𝑓𝑏 is channel capacity in bits per second, B is minimum Nyquist
bandwidth and M is number of discrete signal or voltage levels
𝐵𝑎𝑢𝑑 =
𝑓 𝑏
𝑁
, so Baud is also the bit rate divided by the number of bits
encoded into one signalling element
6
Phase Shift Keying (PSK): Introduction
PSK is a digital modulation scheme which conveys data by
changing/modulating the phase of the carrier signal
Phase of carrier signal is varied in proportional to the information
signal
The carrier signal is also called reference signal
The modulation is done by varying sine and cosine inputs at a precise
time
PSK is often called angle modulated constant amplitude digital
modulation
Simplest form of PSK is Binary phase shift keying (BPSK)
7
Binary Phase Shift Keying (BPSK):
BPSK has values of N=1 and M=2, so two phases for the carrier are
possible
One phase represents a logic 1 and the other phase represents a logic
0. As the input digital signal changes state (i.e., 1 -> 0 or 0 -> 1), the
phase of the output carrier shifts between two angles that are
separated by 180°
8
Binary Phase Shift Keying (BPSK): continued …..
 Any carrier signal is s(t) = A cos (2π𝑓𝑐t +θ) where θ is the phase
For BPSK, we have θ=0 or θ=π, separated by 180 degrees
So, the BPSK signals become A m(t)cos (2π𝑓𝑐t +θ)
𝑣1 𝑡 = Acos2π𝑓𝑐 𝑡 0 ≤ t ≤ T, for 1 and
𝑣2 𝑡 = −Acos2π𝑓𝑐 𝑡 0 ≤ t ≤ T, for 0
where A is a constant, 𝑓𝑐is the carrier frequency and T is the bit
duration
 The signal has a power 𝑃 =
𝐴2
2
means 𝐴 = 2𝑃
9
Binary Phase Shift Keying (BPSK): continued …..
So, the signals 𝑣1,2 𝑡 = ±Acos2π𝑓𝑐 𝑡 becomes
𝑣1,2 𝑡 = ± 2𝑃cos2π𝑓𝑐 𝑡
= ± 𝑃𝑇
2
𝑇
cos2π𝑓𝑐 𝑡
= ± 𝐸
2
𝑇
cos2π𝑓𝑐 𝑡
where E=P*T is the energy contained in a bit duration.
ᶲ1,2 𝑡 = ±
2
𝑇
cos2π𝑓𝑐 𝑡 are the orthonormal functions with unit
energy in a bit duration
10
BPSK Constellation Diagram
 Constellation points are drawn on a
2 dimensional complex co-ordinate
system
ᶲ1 𝑡 =
2
𝑇
cos2π𝑓𝑐 𝑡 0 ≤ t ≤ T
ᶲ2 𝑡 = −
2
𝑇
sin2π𝑓𝑐 𝑡 0 ≤ t ≤ T
11
BPSK transmitter:
Other names for BPSK are phase reversal keying (PRK) and biphase
modulation
BPSK is a form of square-wave modulation of a continuous wave (CW)
signal
Important components of a BPSK transmitter are : Balanced
modulator, level converter, Band pass filter and Reference Carrier
Oscillator
Balanced modulator acts as a phase reversing switch
Another name of Balanced modulator is Balanced Ring modulator
12
BPSK transmitter diagram:
13
BPSK Balanced Ring Modulator:
The balanced modulator has two inputs: (1) a carrier which is in
phase with the reference oscillator and (2) the binary digital data
For the balanced modulator to operate properly, the digital input
voltage must be much greater than the peak carrier voltage
14
BPSK Balanced Ring Modulator Function:
When the binary input logic is 1 When the binary input logic is 0
15
Output of a BPSK waveform:
Logic 1 input produces an analog output signal with a 0°phase angle,
and a logic 0 input produces an analog output signal with a 180°
phase angle
16
BPSK Receiver:
Input signal to receiver maybe +𝑠𝑖𝑛𝜔𝑐 𝑡 or - 𝑠𝑖𝑛𝜔𝑐 𝑡
The coherent carrier recovery circuit detects and regenerates a
carrier signal that is both frequency and phase coherent with the
original transmit carrier
The balanced modulator is a product detector; the output is the
product of the two inputs (the BPSK signal and the recovered carrier)
The low-pass filter (LPF) separates the recovered binary data from
the complex demodulated signal
Coherent BPSK requires that the reference signal at the receiver to be
synchronized in phase and frequency with the received signal
17
BPSK Receiver output:
18
For a BPSK input signal of +𝑠𝑖𝑛𝜔𝑐 𝑡 (logic 1), the output of the
balanced modulator is:
output = (𝑠𝑖𝑛𝜔𝑐 𝑡 )(𝑠𝑖𝑛𝜔𝑐 𝑡 ) = 𝑠𝑖𝑛2
𝑤𝑐 𝑡
Now 𝑠𝑖𝑛2 𝑤𝑐 𝑡 = 0.5(1 –𝑐𝑜𝑠2𝜔𝑐 𝑡 ) = 0.5 - 0.5 𝑐𝑜𝑠2𝜔𝑐 𝑡
output = + 0.5 V = logic 1
filtered out
Advantages and Disadvantages of BPSK:
Advantages
The bit error rate is least in case
of BPSK due to the presence of a
spacing of 2 𝐸 between the
points on the constellation
diagram
BPSK requires half the
transmission energy for the
same bit error rate as in FSK and
ASK
Disadvantages
Costly due to use of Costas
square loop or Costas PLL in
coherent demodulation
The abrupt change of phase in
time domain is an impulse
function which requires infinite
bandwidth for transmission in
frequency domain
19
Applications of BPSK:
BPSK is widely used for wireless LANs, RFID and Bluetooth
communication
BPSK is used in radio communications due to robust BER
20
Other types of Phase Shift Keying:
QPSK - Quadrature Phase Shift Keying
π/4-QPSK - Quadrature Phase Shift Keying
O-QPSK - Offset Quadrature Phase Shift Keying
8 PSK - 8 Point Phase Shift Keying
16 PSK - 16 Point Phase Shift Keying
QAM - Quadrature Amplitude Modulation
16 QAM - 16 Point Quadrature Amplitude Modulation
64 QAM - 64 Point Quadrature Amplitude Modulation
21
QPSK- Quadrature Phase Shift Keying
 Four different phase states in one symbol period
 Two bits of information are transmitted in each symbol
 Twice the bandwidth efficiency of the BPSK
Phase: 0 π/2 π 3π/2 → possible phase values
Symbol: 00 01 11 10
The QPSK signal is given by, s(t) =
2Es
𝑇
cos (2π𝑓𝑐t +(i-1) π/2)
0 ≤ t ≤ T, i=1,2,3,4
22
QPSK Constellation Diagram
23
Now we have two basic functions
Es = 2 Eb since 2 bits are transmitted per symbol
I = in-phase component from sI(t).
Q = quadrature component that is sQ(t).
QPSK Bit Error Rate:
24
BER is related to the distance between constellation points
π/4 -QPSK :
25
 In π/4 QPSK, the maximum phase change is limited to ± 135o , as
compared to 180o for QPSK
 Hence the signal preserves the constant envelop property better
than the band limited QPSK
 This can be demodulated in a coherent or non-coherent fashion
thereby, simplifying the receiver design greatly
 In presence of multipath spread and fading, π/4 QPSK is found to
perform better
Constellation Diagram for π/4 QPSK:
26
QPSK Transmission Technique:
27
π/4 QPSK phase components:
28
Ik = 𝑐𝑜𝑠θk = Ik-1 𝑐𝑜𝑠ϕk - Qk-1 𝑠𝑖𝑛ϕk
Qk = 𝑠𝑖𝑛θk = Ik-1 𝑠𝑖𝑛ϕk + Qk-1 𝑐𝑜𝑠ϕk
where,
Θk = θk -1 + ϕk
θk and θk -1 are the phases of the kth and (k-1)st symbols
The phase shift ϕk is related to the input symbols mik and mqk
π/4 QPSK mathematical analysis:
29
The waveform is represented by:
S(t)= I(t) cos𝜔𝑐 𝑡 – Q(t) 𝑠𝑖𝑛𝜔𝑐 𝑡
where,
I 𝑡 = 𝑘=0
𝑁−1
𝐼k p(t - kTs - Ts /2) = 𝑘=0
𝑁−1
𝑐𝑜𝑠Ɵk p(t - kTs - Ts /2)
Q 𝑡 = 𝑘=0
𝑁−1
𝑄k p(t - kTs - Ts /2) = 𝑘=0
𝑁−1
𝑠𝑖𝑛Ɵk p(t - kTs - Ts /2)
π/4 QPSK FM Discriminator Detection
30
Advantages of π/4- QPSK:
 Among all MPSK schemes, QPSK is the most-often-used scheme
since it does not suffer from BER degradation while the bandwidth
efficiency is increased
In the presence of the multipath spread and fading conditions, pi/4
QPSK performs the best
Signal is demodulated in coherent and non-coherent fashion and
hence the design of the receiver is simple
31
Thank You
An efficient Telecommunications network is the
foundation
upon which an information society is built
32

More Related Content

What's hot

Coherent and Non-coherent detection of ASK, FSK AND QASK
Coherent and Non-coherent detection of ASK, FSK AND QASKCoherent and Non-coherent detection of ASK, FSK AND QASK
Coherent and Non-coherent detection of ASK, FSK AND QASK
naimish12
 
Improving coverage and capacity in cellular systems
Improving coverage and capacity in cellular systemsImproving coverage and capacity in cellular systems
Improving coverage and capacity in cellular systems
Tarek Nader
 
Chap 3
Chap 3Chap 3
Chap 3
Tanuj Patel
 
PULSE CODE MODULATION (PCM)
PULSE CODE MODULATION (PCM)PULSE CODE MODULATION (PCM)
PULSE CODE MODULATION (PCM)
vishnudharan11
 
Multiple access techniques for wireless communications
Multiple access techniques for wireless communicationsMultiple access techniques for wireless communications
Multiple access techniques for wireless communications
METHODIST COLLEGE OF ENGG & TECH
 
Amplitude shift keying
Amplitude shift keyingAmplitude shift keying
Amplitude shift keying
Sunny Kumar
 
Diversity Techniques in Wireless Communication
Diversity Techniques in Wireless CommunicationDiversity Techniques in Wireless Communication
Diversity Techniques in Wireless Communication
Sahar Foroughi
 
Adaptive filter
Adaptive filterAdaptive filter
Adaptive filter
A. Shamel
 
rake reciever ppt
rake reciever pptrake reciever ppt
rake reciever ppt
Divya Shukla
 
MINIMUM SHIFT KEYING(MSK)
MINIMUM SHIFT KEYING(MSK)MINIMUM SHIFT KEYING(MSK)
MINIMUM SHIFT KEYING(MSK)
NARENDRA KUMAR REDDY
 
Wireless Channels Capacity
Wireless Channels CapacityWireless Channels Capacity
Wireless Channels Capacity
Oka Danil
 
Turbo codes.ppt
Turbo codes.pptTurbo codes.ppt
Turbo codes.ppt
Prasant Barik
 
Power dissipation cmos
Power dissipation cmosPower dissipation cmos
Power dissipation cmos
Rajesh Tiwary
 
Ec 2401 wireless communication unit 4
Ec 2401 wireless communication   unit 4Ec 2401 wireless communication   unit 4
Ec 2401 wireless communication unit 4
JAIGANESH SEKAR
 
Lecture 11
Lecture 11Lecture 11
Lecture 11
Sehrish Rafiq
 
Modulation of LED
Modulation of LEDModulation of LED
Modulation of LED
Priyanka Anni
 
ASk,FSK,PSK
ASk,FSK,PSKASk,FSK,PSK
LED and LASER source in optical communication
LED and LASER source in optical communicationLED and LASER source in optical communication
LED and LASER source in optical communication
bhupender rawat
 
DPCM
DPCMDPCM
Digital modulation
Digital modulationDigital modulation
Digital modulation
Ibrahim Omar
 

What's hot (20)

Coherent and Non-coherent detection of ASK, FSK AND QASK
Coherent and Non-coherent detection of ASK, FSK AND QASKCoherent and Non-coherent detection of ASK, FSK AND QASK
Coherent and Non-coherent detection of ASK, FSK AND QASK
 
Improving coverage and capacity in cellular systems
Improving coverage and capacity in cellular systemsImproving coverage and capacity in cellular systems
Improving coverage and capacity in cellular systems
 
Chap 3
Chap 3Chap 3
Chap 3
 
PULSE CODE MODULATION (PCM)
PULSE CODE MODULATION (PCM)PULSE CODE MODULATION (PCM)
PULSE CODE MODULATION (PCM)
 
Multiple access techniques for wireless communications
Multiple access techniques for wireless communicationsMultiple access techniques for wireless communications
Multiple access techniques for wireless communications
 
Amplitude shift keying
Amplitude shift keyingAmplitude shift keying
Amplitude shift keying
 
Diversity Techniques in Wireless Communication
Diversity Techniques in Wireless CommunicationDiversity Techniques in Wireless Communication
Diversity Techniques in Wireless Communication
 
Adaptive filter
Adaptive filterAdaptive filter
Adaptive filter
 
rake reciever ppt
rake reciever pptrake reciever ppt
rake reciever ppt
 
MINIMUM SHIFT KEYING(MSK)
MINIMUM SHIFT KEYING(MSK)MINIMUM SHIFT KEYING(MSK)
MINIMUM SHIFT KEYING(MSK)
 
Wireless Channels Capacity
Wireless Channels CapacityWireless Channels Capacity
Wireless Channels Capacity
 
Turbo codes.ppt
Turbo codes.pptTurbo codes.ppt
Turbo codes.ppt
 
Power dissipation cmos
Power dissipation cmosPower dissipation cmos
Power dissipation cmos
 
Ec 2401 wireless communication unit 4
Ec 2401 wireless communication   unit 4Ec 2401 wireless communication   unit 4
Ec 2401 wireless communication unit 4
 
Lecture 11
Lecture 11Lecture 11
Lecture 11
 
Modulation of LED
Modulation of LEDModulation of LED
Modulation of LED
 
ASk,FSK,PSK
ASk,FSK,PSKASk,FSK,PSK
ASk,FSK,PSK
 
LED and LASER source in optical communication
LED and LASER source in optical communicationLED and LASER source in optical communication
LED and LASER source in optical communication
 
DPCM
DPCMDPCM
DPCM
 
Digital modulation
Digital modulationDigital modulation
Digital modulation
 

Viewers also liked

Qpsk
QpskQpsk
Qpsk
ampas03
 
Phase shift keying(PSK)
Phase shift keying(PSK)Phase shift keying(PSK)
Phase shift keying(PSK)
MOHAN MOHAN
 
PSK (PHASE SHIFT KEYING )
PSK (PHASE SHIFT KEYING )PSK (PHASE SHIFT KEYING )
PSK (PHASE SHIFT KEYING )
vijidhivi
 
Oqpsk
OqpskOqpsk
Phase shift keying Presentation
Phase shift keying PresentationPhase shift keying Presentation
Phase shift keying Presentation
Pavan Goswami
 
Advantages of qpsk
Advantages of qpskAdvantages of qpsk
Advantages of qpsk
Vinaysrichand Bandaru
 
Digital modulation techniques
Digital modulation techniquesDigital modulation techniques
Digital modulation techniques
srkrishna341
 
Hardware Implementation Of QPSK Modulator for Satellite Communications
Hardware Implementation Of QPSK Modulator for Satellite CommunicationsHardware Implementation Of QPSK Modulator for Satellite Communications
Hardware Implementation Of QPSK Modulator for Satellite Communications
pradeepps88
 
Modulation
ModulationModulation
Modulation
sristykp
 
Digital Modulation Unit 3
Digital Modulation Unit 3Digital Modulation Unit 3
Digital Modulation Unit 3
Anil Nigam
 
Digital modulation
Digital modulationDigital modulation
Digital modulation
Ankur Kumar
 
Digital modulation
Digital modulationDigital modulation
Digital modulation
Muhd Iqwan Mustaffa
 
Design and implementation of qpsk modulator using digital subcarrier
Design and implementation of qpsk modulator using digital subcarrierDesign and implementation of qpsk modulator using digital subcarrier
Design and implementation of qpsk modulator using digital subcarrier
Gongadi Nagaraju
 
Digital Modulation Techniques ppt
Digital Modulation Techniques pptDigital Modulation Techniques ppt
Digital Modulation Techniques ppt
Pankaj Singh
 
Transmission of digital signals
Transmission of digital signalsTransmission of digital signals
Transmission of digital signals
Sachin Artani
 
Ece414 chapter3 w12
Ece414 chapter3 w12Ece414 chapter3 w12
Ece414 chapter3 w12
mansoorkhan202020
 
Digital Communication 2
Digital Communication 2Digital Communication 2
Digital Communication 2
admercano101
 
Signal & system
Signal & systemSignal & system
Signal & system
Ghulam Shabbir
 
DPSK(Differential Phase Shift Keying) transmitter and receiver
DPSK(Differential Phase Shift Keying) transmitter and receiverDPSK(Differential Phase Shift Keying) transmitter and receiver
DPSK(Differential Phase Shift Keying) transmitter and receiver
Sumukh Athrey
 
Digital modulation technique
Digital modulation techniqueDigital modulation technique
Digital modulation technique
Nidhi Baranwal
 

Viewers also liked (20)

Qpsk
QpskQpsk
Qpsk
 
Phase shift keying(PSK)
Phase shift keying(PSK)Phase shift keying(PSK)
Phase shift keying(PSK)
 
PSK (PHASE SHIFT KEYING )
PSK (PHASE SHIFT KEYING )PSK (PHASE SHIFT KEYING )
PSK (PHASE SHIFT KEYING )
 
Oqpsk
OqpskOqpsk
Oqpsk
 
Phase shift keying Presentation
Phase shift keying PresentationPhase shift keying Presentation
Phase shift keying Presentation
 
Advantages of qpsk
Advantages of qpskAdvantages of qpsk
Advantages of qpsk
 
Digital modulation techniques
Digital modulation techniquesDigital modulation techniques
Digital modulation techniques
 
Hardware Implementation Of QPSK Modulator for Satellite Communications
Hardware Implementation Of QPSK Modulator for Satellite CommunicationsHardware Implementation Of QPSK Modulator for Satellite Communications
Hardware Implementation Of QPSK Modulator for Satellite Communications
 
Modulation
ModulationModulation
Modulation
 
Digital Modulation Unit 3
Digital Modulation Unit 3Digital Modulation Unit 3
Digital Modulation Unit 3
 
Digital modulation
Digital modulationDigital modulation
Digital modulation
 
Digital modulation
Digital modulationDigital modulation
Digital modulation
 
Design and implementation of qpsk modulator using digital subcarrier
Design and implementation of qpsk modulator using digital subcarrierDesign and implementation of qpsk modulator using digital subcarrier
Design and implementation of qpsk modulator using digital subcarrier
 
Digital Modulation Techniques ppt
Digital Modulation Techniques pptDigital Modulation Techniques ppt
Digital Modulation Techniques ppt
 
Transmission of digital signals
Transmission of digital signalsTransmission of digital signals
Transmission of digital signals
 
Ece414 chapter3 w12
Ece414 chapter3 w12Ece414 chapter3 w12
Ece414 chapter3 w12
 
Digital Communication 2
Digital Communication 2Digital Communication 2
Digital Communication 2
 
Signal & system
Signal & systemSignal & system
Signal & system
 
DPSK(Differential Phase Shift Keying) transmitter and receiver
DPSK(Differential Phase Shift Keying) transmitter and receiverDPSK(Differential Phase Shift Keying) transmitter and receiver
DPSK(Differential Phase Shift Keying) transmitter and receiver
 
Digital modulation technique
Digital modulation techniqueDigital modulation technique
Digital modulation technique
 

Similar to Phase Shift Keying & π/4 -Quadrature Phase Shift Keying

PSK and It's Schemes (using MATLAB)
PSK and It's Schemes (using MATLAB)PSK and It's Schemes (using MATLAB)
PSK and It's Schemes (using MATLAB)
Amirah Nadrah Ghazali
 
Dc unit 2
Dc unit 2Dc unit 2
Mini Project Communication Link Simulation Digital Modulation Techniques Lec...
Mini Project Communication Link Simulation  Digital Modulation Techniques Lec...Mini Project Communication Link Simulation  Digital Modulation Techniques Lec...
Mini Project Communication Link Simulation Digital Modulation Techniques Lec...
University of Hertfordshire, School of Electronic Communications and Electrical Engineering
 
PSK (PHASE SHIFT KEYING )
PSK (PHASE SHIFT KEYING )PSK (PHASE SHIFT KEYING )
PSK (PHASE SHIFT KEYING )
vijidhivi
 
Digital communication methods
Digital communication methodsDigital communication methods
Digital communication methods
Mohammad Bappy
 
Comparative Study and Performance Analysis of different Modulation Techniques...
Comparative Study and Performance Analysis of different Modulation Techniques...Comparative Study and Performance Analysis of different Modulation Techniques...
Comparative Study and Performance Analysis of different Modulation Techniques...
Souvik Das
 
3.2 modulation formats bpsk, qpsk, oqpsk,
3.2 modulation formats   bpsk, qpsk, oqpsk,3.2 modulation formats   bpsk, qpsk, oqpsk,
3.2 modulation formats bpsk, qpsk, oqpsk,
JAIGANESH SEKAR
 
Dcn a03-analog transmission
Dcn a03-analog transmissionDcn a03-analog transmission
Dcn a03-analog transmission
Saurabh Daga
 
Digital modulation basics(nnm)
Digital modulation basics(nnm)Digital modulation basics(nnm)
Digital modulation basics(nnm)
nnmaurya
 
The introduction to Telecomunication engineering
The introduction to Telecomunication engineeringThe introduction to Telecomunication engineering
The introduction to Telecomunication engineering
novrain1
 
Ln3619761985
Ln3619761985Ln3619761985
Ln3619761985
IJERA Editor
 
UNIT-4 Baseband Digital Modulation.pdf
UNIT-4 Baseband Digital Modulation.pdfUNIT-4 Baseband Digital Modulation.pdf
UNIT-4 Baseband Digital Modulation.pdf
Matrusri Engineering College
 
International Journal of Engineering Inventions (IJEI)
International Journal of Engineering Inventions (IJEI)International Journal of Engineering Inventions (IJEI)
International Journal of Engineering Inventions (IJEI)
International Journal of Engineering Inventions www.ijeijournal.com
 
Group no 11
Group no 11Group no 11
EC 8395 - Communication Engineering - Unit 3 m - ary signaling
EC 8395 - Communication Engineering - Unit 3   m - ary signalingEC 8395 - Communication Engineering - Unit 3   m - ary signaling
EC 8395 - Communication Engineering - Unit 3 m - ary signaling
KannanKrishnana
 
Lecture Notes: EEEC6440315 Communication Systems - Digital Modulation
Lecture Notes:  EEEC6440315 Communication Systems - Digital ModulationLecture Notes:  EEEC6440315 Communication Systems - Digital Modulation
Lecture Notes: EEEC6440315 Communication Systems - Digital Modulation
AIMST University
 
mod.pptx
mod.pptxmod.pptx
mod.pptx
AbdullahOmar64
 
Digital modulation techniques
Digital modulation techniquesDigital modulation techniques
Digital modulation techniques
ShriyaGautam3
 
Tele3113 wk10tue
Tele3113 wk10tueTele3113 wk10tue
Tele3113 wk10tue
Vin Voro
 
Digital modulation
Digital modulationDigital modulation
Digital modulation
umair khan
 

Similar to Phase Shift Keying & π/4 -Quadrature Phase Shift Keying (20)

PSK and It's Schemes (using MATLAB)
PSK and It's Schemes (using MATLAB)PSK and It's Schemes (using MATLAB)
PSK and It's Schemes (using MATLAB)
 
Dc unit 2
Dc unit 2Dc unit 2
Dc unit 2
 
Mini Project Communication Link Simulation Digital Modulation Techniques Lec...
Mini Project Communication Link Simulation  Digital Modulation Techniques Lec...Mini Project Communication Link Simulation  Digital Modulation Techniques Lec...
Mini Project Communication Link Simulation Digital Modulation Techniques Lec...
 
PSK (PHASE SHIFT KEYING )
PSK (PHASE SHIFT KEYING )PSK (PHASE SHIFT KEYING )
PSK (PHASE SHIFT KEYING )
 
Digital communication methods
Digital communication methodsDigital communication methods
Digital communication methods
 
Comparative Study and Performance Analysis of different Modulation Techniques...
Comparative Study and Performance Analysis of different Modulation Techniques...Comparative Study and Performance Analysis of different Modulation Techniques...
Comparative Study and Performance Analysis of different Modulation Techniques...
 
3.2 modulation formats bpsk, qpsk, oqpsk,
3.2 modulation formats   bpsk, qpsk, oqpsk,3.2 modulation formats   bpsk, qpsk, oqpsk,
3.2 modulation formats bpsk, qpsk, oqpsk,
 
Dcn a03-analog transmission
Dcn a03-analog transmissionDcn a03-analog transmission
Dcn a03-analog transmission
 
Digital modulation basics(nnm)
Digital modulation basics(nnm)Digital modulation basics(nnm)
Digital modulation basics(nnm)
 
The introduction to Telecomunication engineering
The introduction to Telecomunication engineeringThe introduction to Telecomunication engineering
The introduction to Telecomunication engineering
 
Ln3619761985
Ln3619761985Ln3619761985
Ln3619761985
 
UNIT-4 Baseband Digital Modulation.pdf
UNIT-4 Baseband Digital Modulation.pdfUNIT-4 Baseband Digital Modulation.pdf
UNIT-4 Baseband Digital Modulation.pdf
 
International Journal of Engineering Inventions (IJEI)
International Journal of Engineering Inventions (IJEI)International Journal of Engineering Inventions (IJEI)
International Journal of Engineering Inventions (IJEI)
 
Group no 11
Group no 11Group no 11
Group no 11
 
EC 8395 - Communication Engineering - Unit 3 m - ary signaling
EC 8395 - Communication Engineering - Unit 3   m - ary signalingEC 8395 - Communication Engineering - Unit 3   m - ary signaling
EC 8395 - Communication Engineering - Unit 3 m - ary signaling
 
Lecture Notes: EEEC6440315 Communication Systems - Digital Modulation
Lecture Notes:  EEEC6440315 Communication Systems - Digital ModulationLecture Notes:  EEEC6440315 Communication Systems - Digital Modulation
Lecture Notes: EEEC6440315 Communication Systems - Digital Modulation
 
mod.pptx
mod.pptxmod.pptx
mod.pptx
 
Digital modulation techniques
Digital modulation techniquesDigital modulation techniques
Digital modulation techniques
 
Tele3113 wk10tue
Tele3113 wk10tueTele3113 wk10tue
Tele3113 wk10tue
 
Digital modulation
Digital modulationDigital modulation
Digital modulation
 

More from Naveen Jakhar, I.T.S

Security in Embedded systems
Security in Embedded systems Security in Embedded systems
Security in Embedded systems
Naveen Jakhar, I.T.S
 
MNP sixth adendment regulations
MNP sixth adendment regulationsMNP sixth adendment regulations
MNP sixth adendment regulations
Naveen Jakhar, I.T.S
 
Penalty for violations of EMF radiation norms in India
Penalty for violations of EMF radiation norms in India   Penalty for violations of EMF radiation norms in India
Penalty for violations of EMF radiation norms in India
Naveen Jakhar, I.T.S
 
Inter-Ministerial R&D for EMF radiation guidelines
Inter-Ministerial R&D for EMF radiation guidelinesInter-Ministerial R&D for EMF radiation guidelines
Inter-Ministerial R&D for EMF radiation guidelines
Naveen Jakhar, I.T.S
 
GSM Link Budget
GSM Link BudgetGSM Link Budget
GSM Link Budget
Naveen Jakhar, I.T.S
 
UMTS Protocols
UMTS ProtocolsUMTS Protocols
UMTS Protocols
Naveen Jakhar, I.T.S
 
UMTS core network and its evolution
UMTS core network and its evolutionUMTS core network and its evolution
UMTS core network and its evolution
Naveen Jakhar, I.T.S
 
GSM Air Interface
GSM Air Interface GSM Air Interface
GSM Air Interface
Naveen Jakhar, I.T.S
 
Introduction to SIM and USIM
Introduction to SIM and USIMIntroduction to SIM and USIM
Introduction to SIM and USIM
Naveen Jakhar, I.T.S
 
Drive testing in mobile networks
Drive testing in mobile networksDrive testing in mobile networks
Drive testing in mobile networks
Naveen Jakhar, I.T.S
 
Operating support subsystem (oss) presentation
Operating  support subsystem (oss) presentationOperating  support subsystem (oss) presentation
Operating support subsystem (oss) presentation
Naveen Jakhar, I.T.S
 
Journey of Evolution of UMTS and CDMA
Journey of Evolution of UMTS and CDMAJourney of Evolution of UMTS and CDMA
Journey of Evolution of UMTS and CDMA
Naveen Jakhar, I.T.S
 
Concepts of optical fiber communication
Concepts of optical fiber communicationConcepts of optical fiber communication
Concepts of optical fiber communication
Naveen Jakhar, I.T.S
 
Radio resource management in wcdma
Radio resource management in wcdmaRadio resource management in wcdma
Radio resource management in wcdma
Naveen Jakhar, I.T.S
 
Satellite Communication Theory
Satellite  Communication TheorySatellite  Communication Theory
Satellite Communication Theory
Naveen Jakhar, I.T.S
 
Presentation on satellite antenna
Presentation on satellite antennaPresentation on satellite antenna
Presentation on satellite antenna
Naveen Jakhar, I.T.S
 
Data communication basics
Data communication basicsData communication basics
Data communication basics
Naveen Jakhar, I.T.S
 
Over view of Transmission Technologies & Optical Fiber Communication
Over view of Transmission Technologies & Optical Fiber Communication Over view of Transmission Technologies & Optical Fiber Communication
Over view of Transmission Technologies & Optical Fiber Communication
Naveen Jakhar, I.T.S
 
Overview of Radio Communication
Overview of Radio CommunicationOverview of Radio Communication
Overview of Radio Communication
Naveen Jakhar, I.T.S
 
Internet of Things
Internet of ThingsInternet of Things
Internet of Things
Naveen Jakhar, I.T.S
 

More from Naveen Jakhar, I.T.S (20)

Security in Embedded systems
Security in Embedded systems Security in Embedded systems
Security in Embedded systems
 
MNP sixth adendment regulations
MNP sixth adendment regulationsMNP sixth adendment regulations
MNP sixth adendment regulations
 
Penalty for violations of EMF radiation norms in India
Penalty for violations of EMF radiation norms in India   Penalty for violations of EMF radiation norms in India
Penalty for violations of EMF radiation norms in India
 
Inter-Ministerial R&D for EMF radiation guidelines
Inter-Ministerial R&D for EMF radiation guidelinesInter-Ministerial R&D for EMF radiation guidelines
Inter-Ministerial R&D for EMF radiation guidelines
 
GSM Link Budget
GSM Link BudgetGSM Link Budget
GSM Link Budget
 
UMTS Protocols
UMTS ProtocolsUMTS Protocols
UMTS Protocols
 
UMTS core network and its evolution
UMTS core network and its evolutionUMTS core network and its evolution
UMTS core network and its evolution
 
GSM Air Interface
GSM Air Interface GSM Air Interface
GSM Air Interface
 
Introduction to SIM and USIM
Introduction to SIM and USIMIntroduction to SIM and USIM
Introduction to SIM and USIM
 
Drive testing in mobile networks
Drive testing in mobile networksDrive testing in mobile networks
Drive testing in mobile networks
 
Operating support subsystem (oss) presentation
Operating  support subsystem (oss) presentationOperating  support subsystem (oss) presentation
Operating support subsystem (oss) presentation
 
Journey of Evolution of UMTS and CDMA
Journey of Evolution of UMTS and CDMAJourney of Evolution of UMTS and CDMA
Journey of Evolution of UMTS and CDMA
 
Concepts of optical fiber communication
Concepts of optical fiber communicationConcepts of optical fiber communication
Concepts of optical fiber communication
 
Radio resource management in wcdma
Radio resource management in wcdmaRadio resource management in wcdma
Radio resource management in wcdma
 
Satellite Communication Theory
Satellite  Communication TheorySatellite  Communication Theory
Satellite Communication Theory
 
Presentation on satellite antenna
Presentation on satellite antennaPresentation on satellite antenna
Presentation on satellite antenna
 
Data communication basics
Data communication basicsData communication basics
Data communication basics
 
Over view of Transmission Technologies & Optical Fiber Communication
Over view of Transmission Technologies & Optical Fiber Communication Over view of Transmission Technologies & Optical Fiber Communication
Over view of Transmission Technologies & Optical Fiber Communication
 
Overview of Radio Communication
Overview of Radio CommunicationOverview of Radio Communication
Overview of Radio Communication
 
Internet of Things
Internet of ThingsInternet of Things
Internet of Things
 

Recently uploaded

Pengantar Penggunaan Flutter - Dart programming language1.pptx
Pengantar Penggunaan Flutter - Dart programming language1.pptxPengantar Penggunaan Flutter - Dart programming language1.pptx
Pengantar Penggunaan Flutter - Dart programming language1.pptx
Fajar Baskoro
 
writing about opinions about Australia the movie
writing about opinions about Australia the moviewriting about opinions about Australia the movie
writing about opinions about Australia the movie
Nicholas Montgomery
 
Solutons Maths Escape Room Spatial .pptx
Solutons Maths Escape Room Spatial .pptxSolutons Maths Escape Room Spatial .pptx
Solutons Maths Escape Room Spatial .pptx
spdendr
 
Philippine Edukasyong Pantahanan at Pangkabuhayan (EPP) Curriculum
Philippine Edukasyong Pantahanan at Pangkabuhayan (EPP) CurriculumPhilippine Edukasyong Pantahanan at Pangkabuhayan (EPP) Curriculum
Philippine Edukasyong Pantahanan at Pangkabuhayan (EPP) Curriculum
MJDuyan
 
NEWSPAPERS - QUESTION 1 - REVISION POWERPOINT.pptx
NEWSPAPERS - QUESTION 1 - REVISION POWERPOINT.pptxNEWSPAPERS - QUESTION 1 - REVISION POWERPOINT.pptx
NEWSPAPERS - QUESTION 1 - REVISION POWERPOINT.pptx
iammrhaywood
 
MARY JANE WILSON, A “BOA MÃE” .
MARY JANE WILSON, A “BOA MÃE”           .MARY JANE WILSON, A “BOA MÃE”           .
MARY JANE WILSON, A “BOA MÃE” .
Colégio Santa Teresinha
 
ANATOMY AND BIOMECHANICS OF HIP JOINT.pdf
ANATOMY AND BIOMECHANICS OF HIP JOINT.pdfANATOMY AND BIOMECHANICS OF HIP JOINT.pdf
ANATOMY AND BIOMECHANICS OF HIP JOINT.pdf
Priyankaranawat4
 
The basics of sentences session 6pptx.pptx
The basics of sentences session 6pptx.pptxThe basics of sentences session 6pptx.pptx
The basics of sentences session 6pptx.pptx
heathfieldcps1
 
Wound healing PPT
Wound healing PPTWound healing PPT
Wound healing PPT
Jyoti Chand
 
ISO/IEC 27001, ISO/IEC 42001, and GDPR: Best Practices for Implementation and...
ISO/IEC 27001, ISO/IEC 42001, and GDPR: Best Practices for Implementation and...ISO/IEC 27001, ISO/IEC 42001, and GDPR: Best Practices for Implementation and...
ISO/IEC 27001, ISO/IEC 42001, and GDPR: Best Practices for Implementation and...
PECB
 
BÀI TẬP DẠY THÊM TIẾNG ANH LỚP 7 CẢ NĂM FRIENDS PLUS SÁCH CHÂN TRỜI SÁNG TẠO ...
BÀI TẬP DẠY THÊM TIẾNG ANH LỚP 7 CẢ NĂM FRIENDS PLUS SÁCH CHÂN TRỜI SÁNG TẠO ...BÀI TẬP DẠY THÊM TIẾNG ANH LỚP 7 CẢ NĂM FRIENDS PLUS SÁCH CHÂN TRỜI SÁNG TẠO ...
BÀI TẬP DẠY THÊM TIẾNG ANH LỚP 7 CẢ NĂM FRIENDS PLUS SÁCH CHÂN TRỜI SÁNG TẠO ...
Nguyen Thanh Tu Collection
 
BÀI TẬP BỔ TRỢ TIẾNG ANH 8 CẢ NĂM - GLOBAL SUCCESS - NĂM HỌC 2023-2024 (CÓ FI...
BÀI TẬP BỔ TRỢ TIẾNG ANH 8 CẢ NĂM - GLOBAL SUCCESS - NĂM HỌC 2023-2024 (CÓ FI...BÀI TẬP BỔ TRỢ TIẾNG ANH 8 CẢ NĂM - GLOBAL SUCCESS - NĂM HỌC 2023-2024 (CÓ FI...
BÀI TẬP BỔ TRỢ TIẾNG ANH 8 CẢ NĂM - GLOBAL SUCCESS - NĂM HỌC 2023-2024 (CÓ FI...
Nguyen Thanh Tu Collection
 
BBR 2024 Summer Sessions Interview Training
BBR  2024 Summer Sessions Interview TrainingBBR  2024 Summer Sessions Interview Training
BBR 2024 Summer Sessions Interview Training
Katrina Pritchard
 
A Independência da América Espanhola LAPBOOK.pdf
A Independência da América Espanhola LAPBOOK.pdfA Independência da América Espanhola LAPBOOK.pdf
A Independência da América Espanhola LAPBOOK.pdf
Jean Carlos Nunes Paixão
 
Hindi varnamala | hindi alphabet PPT.pdf
Hindi varnamala | hindi alphabet PPT.pdfHindi varnamala | hindi alphabet PPT.pdf
Hindi varnamala | hindi alphabet PPT.pdf
Dr. Mulla Adam Ali
 
Mule event processing models | MuleSoft Mysore Meetup #47
Mule event processing models | MuleSoft Mysore Meetup #47Mule event processing models | MuleSoft Mysore Meetup #47
Mule event processing models | MuleSoft Mysore Meetup #47
MysoreMuleSoftMeetup
 
Film vocab for eal 3 students: Australia the movie
Film vocab for eal 3 students: Australia the movieFilm vocab for eal 3 students: Australia the movie
Film vocab for eal 3 students: Australia the movie
Nicholas Montgomery
 
Advanced Java[Extra Concepts, Not Difficult].docx
Advanced Java[Extra Concepts, Not Difficult].docxAdvanced Java[Extra Concepts, Not Difficult].docx
Advanced Java[Extra Concepts, Not Difficult].docx
adhitya5119
 
BÀI TẬP BỔ TRỢ TIẾNG ANH LỚP 9 CẢ NĂM - GLOBAL SUCCESS - NĂM HỌC 2024-2025 - ...
BÀI TẬP BỔ TRỢ TIẾNG ANH LỚP 9 CẢ NĂM - GLOBAL SUCCESS - NĂM HỌC 2024-2025 - ...BÀI TẬP BỔ TRỢ TIẾNG ANH LỚP 9 CẢ NĂM - GLOBAL SUCCESS - NĂM HỌC 2024-2025 - ...
BÀI TẬP BỔ TRỢ TIẾNG ANH LỚP 9 CẢ NĂM - GLOBAL SUCCESS - NĂM HỌC 2024-2025 - ...
Nguyen Thanh Tu Collection
 
ZK on Polkadot zero knowledge proofs - sub0.pptx
ZK on Polkadot zero knowledge proofs - sub0.pptxZK on Polkadot zero knowledge proofs - sub0.pptx
ZK on Polkadot zero knowledge proofs - sub0.pptx
dot55audits
 

Recently uploaded (20)

Pengantar Penggunaan Flutter - Dart programming language1.pptx
Pengantar Penggunaan Flutter - Dart programming language1.pptxPengantar Penggunaan Flutter - Dart programming language1.pptx
Pengantar Penggunaan Flutter - Dart programming language1.pptx
 
writing about opinions about Australia the movie
writing about opinions about Australia the moviewriting about opinions about Australia the movie
writing about opinions about Australia the movie
 
Solutons Maths Escape Room Spatial .pptx
Solutons Maths Escape Room Spatial .pptxSolutons Maths Escape Room Spatial .pptx
Solutons Maths Escape Room Spatial .pptx
 
Philippine Edukasyong Pantahanan at Pangkabuhayan (EPP) Curriculum
Philippine Edukasyong Pantahanan at Pangkabuhayan (EPP) CurriculumPhilippine Edukasyong Pantahanan at Pangkabuhayan (EPP) Curriculum
Philippine Edukasyong Pantahanan at Pangkabuhayan (EPP) Curriculum
 
NEWSPAPERS - QUESTION 1 - REVISION POWERPOINT.pptx
NEWSPAPERS - QUESTION 1 - REVISION POWERPOINT.pptxNEWSPAPERS - QUESTION 1 - REVISION POWERPOINT.pptx
NEWSPAPERS - QUESTION 1 - REVISION POWERPOINT.pptx
 
MARY JANE WILSON, A “BOA MÃE” .
MARY JANE WILSON, A “BOA MÃE”           .MARY JANE WILSON, A “BOA MÃE”           .
MARY JANE WILSON, A “BOA MÃE” .
 
ANATOMY AND BIOMECHANICS OF HIP JOINT.pdf
ANATOMY AND BIOMECHANICS OF HIP JOINT.pdfANATOMY AND BIOMECHANICS OF HIP JOINT.pdf
ANATOMY AND BIOMECHANICS OF HIP JOINT.pdf
 
The basics of sentences session 6pptx.pptx
The basics of sentences session 6pptx.pptxThe basics of sentences session 6pptx.pptx
The basics of sentences session 6pptx.pptx
 
Wound healing PPT
Wound healing PPTWound healing PPT
Wound healing PPT
 
ISO/IEC 27001, ISO/IEC 42001, and GDPR: Best Practices for Implementation and...
ISO/IEC 27001, ISO/IEC 42001, and GDPR: Best Practices for Implementation and...ISO/IEC 27001, ISO/IEC 42001, and GDPR: Best Practices for Implementation and...
ISO/IEC 27001, ISO/IEC 42001, and GDPR: Best Practices for Implementation and...
 
BÀI TẬP DẠY THÊM TIẾNG ANH LỚP 7 CẢ NĂM FRIENDS PLUS SÁCH CHÂN TRỜI SÁNG TẠO ...
BÀI TẬP DẠY THÊM TIẾNG ANH LỚP 7 CẢ NĂM FRIENDS PLUS SÁCH CHÂN TRỜI SÁNG TẠO ...BÀI TẬP DẠY THÊM TIẾNG ANH LỚP 7 CẢ NĂM FRIENDS PLUS SÁCH CHÂN TRỜI SÁNG TẠO ...
BÀI TẬP DẠY THÊM TIẾNG ANH LỚP 7 CẢ NĂM FRIENDS PLUS SÁCH CHÂN TRỜI SÁNG TẠO ...
 
BÀI TẬP BỔ TRỢ TIẾNG ANH 8 CẢ NĂM - GLOBAL SUCCESS - NĂM HỌC 2023-2024 (CÓ FI...
BÀI TẬP BỔ TRỢ TIẾNG ANH 8 CẢ NĂM - GLOBAL SUCCESS - NĂM HỌC 2023-2024 (CÓ FI...BÀI TẬP BỔ TRỢ TIẾNG ANH 8 CẢ NĂM - GLOBAL SUCCESS - NĂM HỌC 2023-2024 (CÓ FI...
BÀI TẬP BỔ TRỢ TIẾNG ANH 8 CẢ NĂM - GLOBAL SUCCESS - NĂM HỌC 2023-2024 (CÓ FI...
 
BBR 2024 Summer Sessions Interview Training
BBR  2024 Summer Sessions Interview TrainingBBR  2024 Summer Sessions Interview Training
BBR 2024 Summer Sessions Interview Training
 
A Independência da América Espanhola LAPBOOK.pdf
A Independência da América Espanhola LAPBOOK.pdfA Independência da América Espanhola LAPBOOK.pdf
A Independência da América Espanhola LAPBOOK.pdf
 
Hindi varnamala | hindi alphabet PPT.pdf
Hindi varnamala | hindi alphabet PPT.pdfHindi varnamala | hindi alphabet PPT.pdf
Hindi varnamala | hindi alphabet PPT.pdf
 
Mule event processing models | MuleSoft Mysore Meetup #47
Mule event processing models | MuleSoft Mysore Meetup #47Mule event processing models | MuleSoft Mysore Meetup #47
Mule event processing models | MuleSoft Mysore Meetup #47
 
Film vocab for eal 3 students: Australia the movie
Film vocab for eal 3 students: Australia the movieFilm vocab for eal 3 students: Australia the movie
Film vocab for eal 3 students: Australia the movie
 
Advanced Java[Extra Concepts, Not Difficult].docx
Advanced Java[Extra Concepts, Not Difficult].docxAdvanced Java[Extra Concepts, Not Difficult].docx
Advanced Java[Extra Concepts, Not Difficult].docx
 
BÀI TẬP BỔ TRỢ TIẾNG ANH LỚP 9 CẢ NĂM - GLOBAL SUCCESS - NĂM HỌC 2024-2025 - ...
BÀI TẬP BỔ TRỢ TIẾNG ANH LỚP 9 CẢ NĂM - GLOBAL SUCCESS - NĂM HỌC 2024-2025 - ...BÀI TẬP BỔ TRỢ TIẾNG ANH LỚP 9 CẢ NĂM - GLOBAL SUCCESS - NĂM HỌC 2024-2025 - ...
BÀI TẬP BỔ TRỢ TIẾNG ANH LỚP 9 CẢ NĂM - GLOBAL SUCCESS - NĂM HỌC 2024-2025 - ...
 
ZK on Polkadot zero knowledge proofs - sub0.pptx
ZK on Polkadot zero knowledge proofs - sub0.pptxZK on Polkadot zero knowledge proofs - sub0.pptx
ZK on Polkadot zero knowledge proofs - sub0.pptx
 

Phase Shift Keying & π/4 -Quadrature Phase Shift Keying

  • 1. Phase Shift Keying & π/4 -Quadrature Phase Shift Keying Presentation by: Naveen Jakhar, ITS 1
  • 2. Topics covered in this presentation:  Some basic definitions & concepts of digital communication What is Phase Shift Keying(PSK) ? Binary Phase Shift Keying – BPSK BPSK transmitter & receiver Advantages & Disadvantages of BPSK Pi/4 – QPSK Pi/4 – QPSK transmitter & receiver Advantages of Pi/4- QPSK 2
  • 3. Some basic concepts of Digital Communication: Information capacity: linear function of bandwidth and transmission time i.e. 𝐼 ∝ 𝐵 × 𝑡 where I is information capacity(bits per second) B is bandwidth (hertz) t is transmission time (sec)  Shannon limit for information capacity 𝐼 = 𝐵 log2(1 + 𝑆𝑁𝑅) Where SNR is signal to noise power ratio (unit less quantity) 3
  • 4. M-ary coding: M-ary is a term derived from binary M represents a digit that corresponds to the number of conditions, levels, or combinations possible for a given number of binary variables, for e.g. a digital signal with four possible conditions (voltage levels, frequencies, phases) is an M-ary system where M = 4 Number of bits necessary to produce a given number of conditions is expressed mathematically as 𝑁 = log2 𝑀 or 2 𝑁 = 𝑀 where N is number of necessary bits & M is number of conditions/combinations/levels 4
  • 5. Baud and Minimum bandwidth: Baud or symbols per second- rate of change of a signal on the transmission medium after encoding and modulation have occurred Baud is a unit of transmission rate, modulation rate or symbol rate 𝐵𝑎𝑢𝑑 = 1 𝑡 𝑠 where 𝑡 𝑠is time of one signalling element (seconds) Minimum theoretical bandwidth necessary to propagate a signal is called the minimum Nyquist bandwidth or minimum Nyquist frequency. Thus,𝑓𝑏 = 𝐵, where 𝑓𝑏 is the bit rate in bits per second and B is the ideal Nyquist bandwidth. 5
  • 6. Baud and Minimum bandwidth: continued ….  The relationship between bandwidth and bit rate also applies to the opposite situation. For a given bandwidth (B), the highest theoretical bit rate is 2B. Using multilevel signalling, the Nyquist formula for channel capacity is 𝑓𝑏 = 𝐵log2 𝑀 or 𝑓𝑏 = 𝐵 × 𝑁 => 𝐵 = 𝑓 𝑏 𝑁 where 𝑓𝑏 is channel capacity in bits per second, B is minimum Nyquist bandwidth and M is number of discrete signal or voltage levels 𝐵𝑎𝑢𝑑 = 𝑓 𝑏 𝑁 , so Baud is also the bit rate divided by the number of bits encoded into one signalling element 6
  • 7. Phase Shift Keying (PSK): Introduction PSK is a digital modulation scheme which conveys data by changing/modulating the phase of the carrier signal Phase of carrier signal is varied in proportional to the information signal The carrier signal is also called reference signal The modulation is done by varying sine and cosine inputs at a precise time PSK is often called angle modulated constant amplitude digital modulation Simplest form of PSK is Binary phase shift keying (BPSK) 7
  • 8. Binary Phase Shift Keying (BPSK): BPSK has values of N=1 and M=2, so two phases for the carrier are possible One phase represents a logic 1 and the other phase represents a logic 0. As the input digital signal changes state (i.e., 1 -> 0 or 0 -> 1), the phase of the output carrier shifts between two angles that are separated by 180° 8
  • 9. Binary Phase Shift Keying (BPSK): continued …..  Any carrier signal is s(t) = A cos (2π𝑓𝑐t +θ) where θ is the phase For BPSK, we have θ=0 or θ=π, separated by 180 degrees So, the BPSK signals become A m(t)cos (2π𝑓𝑐t +θ) 𝑣1 𝑡 = Acos2π𝑓𝑐 𝑡 0 ≤ t ≤ T, for 1 and 𝑣2 𝑡 = −Acos2π𝑓𝑐 𝑡 0 ≤ t ≤ T, for 0 where A is a constant, 𝑓𝑐is the carrier frequency and T is the bit duration  The signal has a power 𝑃 = 𝐴2 2 means 𝐴 = 2𝑃 9
  • 10. Binary Phase Shift Keying (BPSK): continued ….. So, the signals 𝑣1,2 𝑡 = ±Acos2π𝑓𝑐 𝑡 becomes 𝑣1,2 𝑡 = ± 2𝑃cos2π𝑓𝑐 𝑡 = ± 𝑃𝑇 2 𝑇 cos2π𝑓𝑐 𝑡 = ± 𝐸 2 𝑇 cos2π𝑓𝑐 𝑡 where E=P*T is the energy contained in a bit duration. ᶲ1,2 𝑡 = ± 2 𝑇 cos2π𝑓𝑐 𝑡 are the orthonormal functions with unit energy in a bit duration 10
  • 11. BPSK Constellation Diagram  Constellation points are drawn on a 2 dimensional complex co-ordinate system ᶲ1 𝑡 = 2 𝑇 cos2π𝑓𝑐 𝑡 0 ≤ t ≤ T ᶲ2 𝑡 = − 2 𝑇 sin2π𝑓𝑐 𝑡 0 ≤ t ≤ T 11
  • 12. BPSK transmitter: Other names for BPSK are phase reversal keying (PRK) and biphase modulation BPSK is a form of square-wave modulation of a continuous wave (CW) signal Important components of a BPSK transmitter are : Balanced modulator, level converter, Band pass filter and Reference Carrier Oscillator Balanced modulator acts as a phase reversing switch Another name of Balanced modulator is Balanced Ring modulator 12
  • 14. BPSK Balanced Ring Modulator: The balanced modulator has two inputs: (1) a carrier which is in phase with the reference oscillator and (2) the binary digital data For the balanced modulator to operate properly, the digital input voltage must be much greater than the peak carrier voltage 14
  • 15. BPSK Balanced Ring Modulator Function: When the binary input logic is 1 When the binary input logic is 0 15
  • 16. Output of a BPSK waveform: Logic 1 input produces an analog output signal with a 0°phase angle, and a logic 0 input produces an analog output signal with a 180° phase angle 16
  • 17. BPSK Receiver: Input signal to receiver maybe +𝑠𝑖𝑛𝜔𝑐 𝑡 or - 𝑠𝑖𝑛𝜔𝑐 𝑡 The coherent carrier recovery circuit detects and regenerates a carrier signal that is both frequency and phase coherent with the original transmit carrier The balanced modulator is a product detector; the output is the product of the two inputs (the BPSK signal and the recovered carrier) The low-pass filter (LPF) separates the recovered binary data from the complex demodulated signal Coherent BPSK requires that the reference signal at the receiver to be synchronized in phase and frequency with the received signal 17
  • 18. BPSK Receiver output: 18 For a BPSK input signal of +𝑠𝑖𝑛𝜔𝑐 𝑡 (logic 1), the output of the balanced modulator is: output = (𝑠𝑖𝑛𝜔𝑐 𝑡 )(𝑠𝑖𝑛𝜔𝑐 𝑡 ) = 𝑠𝑖𝑛2 𝑤𝑐 𝑡 Now 𝑠𝑖𝑛2 𝑤𝑐 𝑡 = 0.5(1 –𝑐𝑜𝑠2𝜔𝑐 𝑡 ) = 0.5 - 0.5 𝑐𝑜𝑠2𝜔𝑐 𝑡 output = + 0.5 V = logic 1 filtered out
  • 19. Advantages and Disadvantages of BPSK: Advantages The bit error rate is least in case of BPSK due to the presence of a spacing of 2 𝐸 between the points on the constellation diagram BPSK requires half the transmission energy for the same bit error rate as in FSK and ASK Disadvantages Costly due to use of Costas square loop or Costas PLL in coherent demodulation The abrupt change of phase in time domain is an impulse function which requires infinite bandwidth for transmission in frequency domain 19
  • 20. Applications of BPSK: BPSK is widely used for wireless LANs, RFID and Bluetooth communication BPSK is used in radio communications due to robust BER 20
  • 21. Other types of Phase Shift Keying: QPSK - Quadrature Phase Shift Keying π/4-QPSK - Quadrature Phase Shift Keying O-QPSK - Offset Quadrature Phase Shift Keying 8 PSK - 8 Point Phase Shift Keying 16 PSK - 16 Point Phase Shift Keying QAM - Quadrature Amplitude Modulation 16 QAM - 16 Point Quadrature Amplitude Modulation 64 QAM - 64 Point Quadrature Amplitude Modulation 21
  • 22. QPSK- Quadrature Phase Shift Keying  Four different phase states in one symbol period  Two bits of information are transmitted in each symbol  Twice the bandwidth efficiency of the BPSK Phase: 0 π/2 π 3π/2 → possible phase values Symbol: 00 01 11 10 The QPSK signal is given by, s(t) = 2Es 𝑇 cos (2π𝑓𝑐t +(i-1) π/2) 0 ≤ t ≤ T, i=1,2,3,4 22
  • 23. QPSK Constellation Diagram 23 Now we have two basic functions Es = 2 Eb since 2 bits are transmitted per symbol I = in-phase component from sI(t). Q = quadrature component that is sQ(t).
  • 24. QPSK Bit Error Rate: 24 BER is related to the distance between constellation points
  • 25. π/4 -QPSK : 25  In π/4 QPSK, the maximum phase change is limited to ± 135o , as compared to 180o for QPSK  Hence the signal preserves the constant envelop property better than the band limited QPSK  This can be demodulated in a coherent or non-coherent fashion thereby, simplifying the receiver design greatly  In presence of multipath spread and fading, π/4 QPSK is found to perform better
  • 26. Constellation Diagram for π/4 QPSK: 26
  • 28. π/4 QPSK phase components: 28 Ik = 𝑐𝑜𝑠θk = Ik-1 𝑐𝑜𝑠ϕk - Qk-1 𝑠𝑖𝑛ϕk Qk = 𝑠𝑖𝑛θk = Ik-1 𝑠𝑖𝑛ϕk + Qk-1 𝑐𝑜𝑠ϕk where, Θk = θk -1 + ϕk θk and θk -1 are the phases of the kth and (k-1)st symbols The phase shift ϕk is related to the input symbols mik and mqk
  • 29. π/4 QPSK mathematical analysis: 29 The waveform is represented by: S(t)= I(t) cos𝜔𝑐 𝑡 – Q(t) 𝑠𝑖𝑛𝜔𝑐 𝑡 where, I 𝑡 = 𝑘=0 𝑁−1 𝐼k p(t - kTs - Ts /2) = 𝑘=0 𝑁−1 𝑐𝑜𝑠Ɵk p(t - kTs - Ts /2) Q 𝑡 = 𝑘=0 𝑁−1 𝑄k p(t - kTs - Ts /2) = 𝑘=0 𝑁−1 𝑠𝑖𝑛Ɵk p(t - kTs - Ts /2)
  • 30. π/4 QPSK FM Discriminator Detection 30
  • 31. Advantages of π/4- QPSK:  Among all MPSK schemes, QPSK is the most-often-used scheme since it does not suffer from BER degradation while the bandwidth efficiency is increased In the presence of the multipath spread and fading conditions, pi/4 QPSK performs the best Signal is demodulated in coherent and non-coherent fashion and hence the design of the receiver is simple 31
  • 32. Thank You An efficient Telecommunications network is the foundation upon which an information society is built 32