This document provides information about YuVa InnoVators, which aims to teach participants about recent developments in mobile phone technologies and wireless communication techniques. Specifically, it discusses using diversity techniques to improve wireless communication performance without increasing transmitted power. The document outlines the objectives, such as learning how diversity techniques mitigate fading issues. It also provides tutorials on key topics like modulation methods, wireless channels, fading, and diversity approaches.

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3.  Purpose
 Objectives
 Expected Benefits
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4. An overview of diversity techniques.
How diversity technique can be utilized for performance
improvement.
Provide MATLAB computing to understand the
performance improvement using diversity technique.
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5.  To acquire an update on the development of mobile phone technologies with potential for
supporting our own future carrier.
 To learn about the present wireless communication condition in our country.
 To demonstrate some latest technologies in communication field
 How diversity techniques are used to improve the performance of the radio channel without
any increase in the transmitted power.
 To evaluate the system performance degradation due to fading.
 To undergo mathematical analysis and MATLAB simulation for analyzing the performance of
Raleigh fading channels.
 To study Uniqueness of Mobile Radio Environment.
 To overall basic knowledge about telecommunication.
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6. To know about the recent status of telecommunication sector
To work on the improvement of the communication services
Diversity is now being considered as one of the most
solution to mitigate the fading problem in wireless
communication.
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7.  Communication signifies transmission, reception and
processing of information by electric means.
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9.  An information source, presumably a person who creates a message.
 The message, which is both sent by the information source and received by the destination.
 A transmitter, a telephone instrument that captures an audio signal, converts it into an electronic signal, and amplifies it
for transmission through the telephone network.
 A carrier or channel, which acts as a bridge between the transmitter and receiver. As the signal propagates through the
channel, it gets attenuated due to transmission loss and distorted due to various nonlinear effects and interference.
Channel can consist of a pair of wires, a coaxial cable or a radio link through free space
 Noise, in the form of secondary signals that obscure or confuse the signal carried
 Receiver It extracts the weakened and distorted signal from the channel, amplifies it and restores it to its original
form and then passes it into the message destination.
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10.  OPTICAL COMMUNICATION SYSTEM
 RADIO COMMUNICATION
 POWER LINE COMMUNICATIONS SYSTEMS
 DUPLEX COMMUNICATION SYSTEM
 TACTICAL COMMUNICATIONS SYSTEM
 WIRELESS COMMUNICATION
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11.  The transfer of information over a distance without
the use of electrical conductors or "wires“
 An electromagnetic signal is created, modulated,
amplified, and broadcast to one or more receivers that
can be fixed or mobile.
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12. Every wireless system must have the basics of a transmitter
(modulation), receiver (demodulation) and a channel
(frequency) to transmit the signal from a stationary or mobile
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13. A TYPICAL GSM BASE STATION
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14. High Frequency (HF) 3-30 MHz (PRIME BAND)
Very High Frequency (VHF) 30-300 MHz (PRIME BAND)
Ultra High Frequency (UHF) 300-3000 MHz (PRIME BAND)
Super High Frequency (SHF) 3-30 GHz (INCREASING USE)
Extremely High Frequency (EHF) 30-300 GHz (PROSPECTIVE USE)
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15.  SECURITY SYSTEMS
 TELEVISION REMOTE CONTROL
 CELLULAR TELEPHONY (PHONES AND MODEMS)
 Wi–Fi
 WIRELESS ENERGY TRANSFER
 COMMUNICATIONS SATELLITEYuVa InnoVators

16. In telecommunications, modulation
is the process of conveying a
message signal inside another signal
that can be physically transmitted.
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17. The aim of digital modulation is to transfer a digital
bit stream over an analog passband channel
The aim of analog modulation is to transfer an analog
baseband (or lowpass) signal
The aim of pulse modulation methods is to transfer a
narrowband analog signal
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18. MODULATION
ANALOG
MODULATION
AMPLITUDE MODULATION
FREQUENCY MODULATION
PHASE MODULATION
DIGITAL
MODULATION
AMPLITUDE-SHIFT KEYING
FREQUENCY-SHIFT KEYING
PHASE-SHIFT KEYING
PULSE
MODULATION
PULSE-AMPLITUDE MODULATION
PULSE-WIDTH MODULATION
PULSE-POSITION MODULATION
PULSE-CODE MODULATIONYuVa InnoVators

19.  The modulation is applied continuously in response to the
analog information signal.
The amplitude of the carrier
signal is varied in accordance to the
instantaneous amplitude of the
modulating signal.
The frequency of the carrier
signal is varied in accordance to the
instantaneous frequency of the
modulating signal.
The phase shift of the carrier
signal is varied in accordance to the
instantaneous phase shift of the
modulating signal.
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20. An analog carrier signal is
modulated by a digital bit stream
Considered as digital-to-analog
conversion
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21. AMPLITUDE-SHIFT KEYING (ASK)
FREQUENCY-SHIFT KEYING (FSK)
PHASE-SHIFT KEYING (PSK)YuVa InnoVators

22. Pulse modulation schemes aim at transferring a narrowband analog
signal over an analog baseband channel as a two-level signal by
modulating a pulse wave.
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23.  Essentially identical to coded OFDM (COFDM) and discrete
multi-tone modulation (DMT), is a frequency-division
multiplexing (FDM) scheme utilized as a digital multi-carrier
modulation method.
 Orthogonal Frequency-Division Multiple Access (OFDMA)
is a multi-user version of the popular Orthogonal frequency-
division multiplexing (OFDM) digital modulation scheme.
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24. AN OFDM (A) MODULATOR AND (B) DEMODULATOR
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25. OFDM SIMULATION FLOWCHART
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26.  Flexibility of deployment across various frequency bands with little needed
modification to the air interface.
 Averaging interferences from neighboring cells, by using different basic carrier
permutations between users in different cells.
 Interferences within the cell are averaged by using allocation with cyclic
permutations.
 Enables orthogonality in the uplink by synchronizing users in time and frequency.
 Enables Single Frequency Network coverage, where coverage problem exists and
gives excellent coverage.
 Offers Frequency diversity by spreading the carriers all over the used spectrum.
 Offers Time diversity by optional interleaving of carrier groups in time.YuVa InnoVators

27.  FADING
 INTERFERENCE
 ERROR BURST
 FREQUENCY REUSES
 NOISE LEVEL IN CELLULAR FREQUENCY BAND
 PATH LOSS
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28.  The fading is deviation of the attenuation that a carrier-
modulated telecommunication signal experiences over certain
propagation media.
 The fading may vary with time, geographical position and/or
radio frequency, and is often modeled as a random process.
 In wireless systems, fading may either be due to multipath
propagation or due to shadowing from obstacles affecting the
wave propagation.
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29. 1. Multipath Spread Tm
It tells us the maximum delay between paths of significant
power in the channel
2. Coherence Bandwidth (Δ)c
Gives an idea of how far apart –in frequency- for signals to
undergo different degrees of fading
3. Coherence Time (t)c
Gives a measure of the time duration over which the channel
impulse response is essentially invariant (highly correlated)
4. Doppler Spread Bd
It gives the maximum range of Doppler shifts
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30. A MOBILE RADIO ENVIRONMENT
(a) PROPAGATION LOSS
(b) MULTIPATH FADING
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31. FAST FADING vs. SLOW FADING
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32.  CO-CHANNEL INTERFERENCE
- Co-channel interference or CCI is crosstalk from two
different radio transmitters using the same frequency.
 ADJACENT-CHANNEL INTERFERENCE
- Adjacent-channel interference or ACI is interference
caused by extraneous power from a signal in an adjacent
channel.
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33. The core concept of the cellular mobile radio system.
Users in different geographic locations may
simultaneously use the same frequency .
The frequency reuse concept can be used in the time
domain and the space domain.
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34. N-CELL REUSE PATTERNYuVa InnoVators

35. Tow-ray models for mobile radio environments
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36. TIME DIVERSITY
FREQUENCY DIVERSITY
SPACE DIVERSITY
SPATIAL DIVERSITY
PATTERN DIVERSITY
POLARIZATION DIVERSITY
MULTIUSER DIVERSITY
COOPERATIVE DIVERSITYYuVa InnoVators

37.  Time Diversity is used in digital communication systems
to combat that the transmissions channel may suffer from
error bursts due to time-varying channel conditions.
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38.  The signal is transferred using several frequency channels
or spread over a wide spectrum that is affected by
frequency-selective fading.
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39.  Antenna diversity, also known as space diversity, is any one of
several wireless diversity schemes that use two or more
antennas to improve the quality and reliability of a wireless
link. Often, especially in urban and indoor environments, there
is not a clear line-of-sight (LOS) between transmitter and
receiver. Instead the signal is reflected along multiple paths
before finally being received
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41.  Spatial diversity employs multiple antennas,
usually with the same characteristics, that are
physically separated from one another.
Depending upon the expected incidence of the
incoming signal, sometimes a space on the
order of a wavelength is sufficient.
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42.  Pattern diversity consists of two or more co-
located antennas with different radiation patterns.
This type of diversity makes use of directive
antennas that are usually physically separated by
some (often short) distance.
 Collectively they are capable of discriminating a
large portion of angle space and can provide a
higher gain versus a single omni directional
radiator.
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43.  Multiple versions of a signal are transmitted and received via
antennas with different polarization.
LINEAR CIRCULAR ELLIPTICAL
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44.  Achieves antenna diversity gain by using the
cooperation of distributed antennas belonging to
each node.
 Cooperative diversity is a cooperative multiple
antenna technique for improving or maximizing
total network channel capacities for any given set
of bandwidths .
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45. SELECTION COMBINING
SWITCHING COMBINING
EQUAL GAIN COMBINING
MAXIMAL-RATIO COMBINING
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46.  Of the N received signals, the strongest signal is selected.
 Any additional gain diminishes rapidly with the increasing number of
channels.
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47. • The receiver switches to another signal when current signal drops below a
predefined threshold.
• This is a less efficient technique than selection combining.
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48.  All the received signals are summed coherently.
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49. • The received signals are weighted with respect to their SNR
and then summed.
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50. Use of multiple antennas at both the transmitter and
receiver to improve quality (BER) or data rate
(bits/sec).
 One of several forms of smart antenna technology.
 Core scheme of MIMO: space-time coding (STC)
 Two main functions of STC: diversity & multiplexing
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51. Spatial Diversity: Increased SNR Spatial Multiplexing: Increased rate
Receive and transmit diversity mitigates fading and significantly
improves link quality
Spatial multiplexing yields substantial increase in spectral
efficiency
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54. Diversity plays an important role in combating fading and co-channel
interference and avoiding error bursts. It is based on the fact that
individual channels experience different levels of fading and
interference. Multiple versions of the same signal may be transmitted
and/or received and combined in the receiver. Alternatively, a
redundant forward error correction code may be added and different
parts of the message transmitted over different channels. Diversity
techniques may exploit the multipath propagation, resulting in a
diversity gain, often measured in decibels.YuVa InnoVators

55. Comparison of the Performance of a wireless Communication System using
Antenna DiversityYuVa InnoVators

56. SNR K
No. of receiving
antenna (Rx.)
BER-Floor for a Un-
coded System
40dB 0dB
2 10-5
3 10-7
4 10-8
5 10-10
6 10-12
The improvement of performance of a Wireless System using Multiple Antenna
(Diversity) System
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57. Comparison of Performance between one (L=1) and six receiving (L=6)
Antenna of wireless Communication System using Maximum Ratio
Combining Diversity Method
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58. SNR K
No. of receiving
antenna (Rx.)
BER-Floor for the
System
50dB 0dB
1 10-5
6 10-22
Comparison of Performance between one (L=1) and six receiving (L=6)
Antenna of wireless Communication System
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59. Comparison of Performance between one (L=1) and eight receiving
(L=8) Antenna of wireless Communication System using Maximum
Ratio Combining Diversity MethodYuVa InnoVators

60. Comparison of Performance between one (L=1) and eight receiving (L=8)
Antenna of wireless Communication System
SNR K
No. of receiving
antenna (Rx.)
BER-Floor for the
System
60dB 0dB
1 10-4
8 10-34
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61. Comparison of Performance for different diversity schemes of a Wireless
Communication System using Maximum Ratio Combining (MRC).
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62. Comparison of Performance for different diversity schemes of a Wireless
Communication System.
SNR K
No. of receiving
antenna (Rx.)
BER-Floor for the
System
60dB 0dB
1 10-4
2 10-10
4 10-20
6 10-27
8 10-35
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63.  The diversity is used to provide the receiver with several replicas of the same
signal. Diversity techniques are used to improve the performance of the radio
channel without any increase in the transmitted power. As higher as the
received signal replicas are de correlated, as much as the diversity gain
 Among different combining techniques MRC has the best performance and
the highest complexity, SC has the lowest performance and the least
complexity.
 BER performance of a Multi-antenna system for both Coded and Un-coded
system considering several number of Receiving Antenna. From the both
figures it is noticed that there is remarkable improvement in the achievable
probability of bit error as number of receiving antenna increase. The BER is
measured as 10-5 , 10-7 , 10-8 ,10-10 , and 10-12 for Receiving Antenna
Numbers 2, 3, 4, 5 and 6 respectively. Also it is revealed that Bit-Error-
Rate of a Multi-Antenna System is 10-23, 10-30 , 10-38 , 10-47 and 10-56
for Receiving Antenna Numbers 2, 3, 4, 5 and 6 respectively.
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