United Arab Emirates University College of Engineering Graduation Projects Unit

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United Arab Emirates UniversityCollege of
EngineeringGraduation Projects Unit
Ultra-Wideband PHY/MAC

• Presented By ID
• Ali Omar 20000 5343
• Moaz Al-Ibrahim 200001488
• Nader Al-Ghazu 200101780
• Advisor
• Dr. Mohamed Abdul Hafez
• Coordinator
• Dr. Mohamed Younes

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Outline

• Introduction
• GP I Overview
• Multi-User UWB System
• System Description
• Theoretical analyses
• Simulation Results
• Design Issue
• WLAN Interference
• MAC Layer
• Conclusion

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Outline

• Introduction
• GP I Overview
• Multi-User UWB System
• System Description
• Theoretical analyses
• Simulation Results
• Design Issue
• WLAN Interference
• MAC Layer
• Conclusion

Introduction
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Wireless Technology
Introduction

• Importance of Wireless Communication
• Wireless Demand
• High capacity
• Secure
• Coexistence
• Place in Radio Frequency Spectrum

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Crowded RF
Introduction
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Solution is UWB
Introduction

• How?
• Low power wide frequency range
• Results
• Coexist with the current systems
• No interference
• Avoid expensive licenses

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UWB Concept
Introduction

• Very narrow pulses
• Large Bandwidth low power

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UWB Advantages
Introduction

• Frequency Spectrum Sharing
• Large Channel Capacity
• Work with low SNR

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UWB Advantages
Introduction

• Simple transceiver architecture
• Resistance to jamming
• Low probability of intercept detection

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GP1 Overview
Introduction

• Simulation environment for single user
• The effect of pulse shape and the modulation
  scheme on BER were all studied
• As a result
• The Biphase modulation showed the lowest BER
• The second derivative Gaussian pulse showed
  better results at high values of SNR

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Outline

• Introduction
• GP I Overview
• Multi-User UWB System
• System Description
• Theoretical analyses
• Simulation Results
• Design Issue
• WLAN Interference
• MAC Layer
• Conclusion

Multi-User UWB System
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UWB Multi-User
Multi-User UWB System

• Multi-user communication techniques
• System Description
• Theoretical Derivation
• Multi-user Simulation Environment

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Multi-User Techniques
Multi-User UWB System

• Share same media by different user
• Techniques
• TDMA Time Division Multiple Access
• FDMA Frequency Division Multiple Access
• CDMA Code Division Multiple Access

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TDMA
Multi-User UWB System

• The sent data is divided into time frames
• Each frame is divided into smaller fragments for
  different users

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FDMA
Multi-User UWB System

• The frequency spectrum is divided into several
  slots
• Each user occupies a different channel

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CDMA
Multi-User UWB System

• Each user uses a special orthogonal code
• All signals are sent together at the same time
  and frequency

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System Description
Multi-User UWB System

• The UWB system consists of
• n users distributed randomly
• Different power attenuation
• Random delays for different users
• Sources produce binary sequence equally likely
• Impulse response of the multi path free channel
  between user n and the receiver

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System Description
Multi-User UWB System
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Theoretical
Multi-User UWB System

• The theoretical model created by deriving the
  equations for the probability of error

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Theoretical
Multi-User UWB System

• Final equation for theoretical BER

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Theoretical
Multi-User UWB System

• MATLAB was used to solve the pervious equation to
  determine Pe
• A range of SNR values were used
• The calculation was done for different number of
  users
• 5 users
• 20 users
• 50 users

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Numerical Result
Multi-User UWB System

• Different Modulation, Fix user

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Numerical Result
Multi-User UWB System

• Biphase Modulation, Different user

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Numerical Result
Multi-User UWB System

• PPM Modulation, Different user

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Numerical Result
Multi-User UWB System

• Different Modulation, Different user

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Simulation Results
Multi-User UWB System

• Simulation environment was created by MATLAB
• It models the UWB mutli-user system
• It consist of a main loop that calls different
  functions

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Simulation Results
Multi-User UWB System
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Simulation Results
Multi-User UWB System

• The main_UWB_multiuser file
• Calculates
• Pe for a range of SNR values
• Pe for different numbers of users and a fixed SNR
• Pe for a variable distance
• Pe for different delay factors (a).

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Simulation Results
Multi-User UWB System

• The generate_data function
• Generate a sequence of random binary data for
  each user
• The random seed is reset
• A flag of ones added

1 1 1 0 1 0 0 1 0 0 1 1 0 1 1 1 0 0 1 0 0 0 1 1
0 1 1 1 1 0 1 0 0 1 0 0 1 1 0 1 1 1 0 0 1 0 0 0
1 1 0 1
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Simulation Results
Multi-User UWB System

• The generate_pulse function
• Generates a second derivative Gaussian pulse
• Specified number of samples
• According to the IEEE standards
• Pulse duration 0.7 ns
• Shaping factor 0.277 n
• Then the pulse energy is normalized

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Simulation Results
Multi-User UWB System

• The multi_modulation function
• It modulates data using either Biphase or PPM
  modulation schemes
• TDMA is used to share the channel
• For different users
• Different delays
• Different transmitting powers

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Simulation Results
Multi-User UWB System
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Delay
Multi-User UWB System
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Delay
Multi-User UWB System
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Powers
Multi-User UWB System
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Simulation Results
Multi-User UWB System

• The gauss_channel function
• This function simulates an AWAGN channel
• The noise power is calculated from the SNR
• White Gaussian noise is generated and added to
  the transmitted signals

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Multi-User UWB System
SNR 20 dB
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Multi-User UWB System
SNR 10 dB
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Simulation Results
Multi-User UWB System

• The multi_receiver function
• It simulates a coherent correlation receiver
• It demodulates the desired user data
• Perfect synchronization.
• The received data is compared with the
  transmitted data, Pe is calculated
• Loop ? Average ? Plot Results

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Simulation Results
Multi-User UWB System
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Simulation Results
Multi-User UWB System
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Outline

• Introduction
• GP I Overview
• Multi-User UWB System
• System Description
• Theoretical analyses
• Simulation Results
• Design Issue
• WLAN Interference
• MAC Layer
• Conclusion

Design Issue
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Design Issues
Design Issue

• The performance of the UWB vs distance
• The scenario
• 3m x 4m room
• Randomly distributed nodes
• The desired user moves from
• Receiver ? Room corner
• 0 m ? 2.5 m
• Different numbers of users
• SNR 1dB

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The Room
Design Issue
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Free Space Model
Design Issue

• The Pe for was calculated verses the distance
• The power received free space model

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Results
Design Issue
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Results
Design Issue
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Results
Design Issue
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Results
Design Issue
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Results
Design Issue

• The system show better performance at
• Smaller distances
• Fewer number of MUI
• At small distances
• MUI effect on Pe gt Distance effect
• At larger distance
• MUI effect lt Distance effect

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Outline

• Introduction
• GP I Overview
• Multi-User UWB System
• System Description
• Theoretical analyses
• Simulation Results
• Design Issue
• WLAN Interference
• MAC Layer
• Conclusion

WLAN Interference
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Co-existence of IEEE 802.11a WLAN with UWB
WLAN Interference

• Outline
• Co-existence scenario
• Theoretical derivation
• Design results

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The IEEE 802.11a WLAN
WLAN Interference
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The IEEE 802.11a WLAN
WLAN Interference

• The scenario

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Theoretical derivation
WLAN Interference

• The victim receiver experienced a total
  interference power due to the UWB devices given
  by

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Theoretical derivation
WLAN Interference

• The SINR at the victim receiver is defined by

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Theoretical derivation
WLAN Interference

• The total amount of UWB interference
  corresponding to an M dB degradation can be
  deduced such that

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Theoretical derivation
WLAN Interference
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Design Results
WLAN Interference
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Design Results
WLAN Interference
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Design Results
WLAN Interference

• The signal decreases with an increase in the
  distance between the user and the access point.
• SNR decreases because the noise is constant and
  the signal is decreasing

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Design Results
WLAN Interference
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Design Results
WLAN Interference
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Design Results
WLAN Interference
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Design Results
WLAN Interference
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Outline

• Introduction
• GP I Overview
• Multi-User UWB System
• System Description
• Theoretical analyses
• Simulation Results
• Design Issue
• WLAN Interference
• MAC Layer
• Conclusion

MAC Layer
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The MAC Layer
MAC Layer

• The Media Access Control (MAC) is a sub-layer
  part of the part of the seven-layer OSI model
  data link
• It provides addressing channel access control
  that makes it possible for several terminals to
  communicate within a network

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MAC Layer
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MAC Layer
MAC Layer

• The MAC layer provides an addressing mechanism
  called physical address or MAC address
• This is a unique serial number assigned to each
  network adapter
• It makes it possible to deliver data packets to a
  destination within a subnetwork

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UWB MAC Requirements
MAC Layer

• The UWB system
• Short pulses
• Short range
• High speed
• This criteria should be considered in selecting a
  MAC technique

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System Selection
MAC Layer

• There are two types of systems
• Personal Networks systems
• Sensor Network Systems

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MAC Protocol
MAC Layer

• IEEE 802.15.3 protocol is design for the short
  period pulse
• A piconet is controlled by a master called the
  Piconet Controller
• PNC which grants accesses to the medium using
  TDMA

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Bluetooth IEEE 802.15.3
MAC Layer
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Design Based on Packet Collision
MAC Layer

• Packet inter-arrival process follows a Poisson
  distribution
• Each packet contains a set of pulses
• Probability that one or more pulses will collide
  with the useful pulse

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Results
MAC Layer
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Outline

• Introduction
• GP I Overview
• Multi-User UWB System
• System Description
• Theoretical analyses
• Simulation Results
• Design Issue
• WLAN Interference
• MAC Layer
• Conclusion

Conclusion
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Conclusion
Conclusion

• In this project, the UWB communication system was
  studied and analyzed
• The concept, background and GP1 results were
  reviewed
• Then the UWB multi-user system
• Numerically analyzed
• Simulated using MATLAB (TDMA, second derivative
  Gaussian pulse, PPM Biphase modulations)

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Conclusion
Conclusion

• The effect of distance was analyzed and simulated
• Co-existence of WLAN 802.11a with UWB devices
• The effect of UWB on the data rate
• The effect on Coverage area
• The suitable MAC protocol for UWB multi-user
  system was demonstrated
• The effect of number of active users
• The effect of packet duration

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Thank you for listening
Questions?