Wireless Channel Estimation

1
Wireless Channel Estimation

• Faisal Darbari
• University of Strathclyde
• faisal_at_eee.strath.ac.uk

2
Introduction

• To determine the relationship between the
  Received and the Transmitted signal.
• Determination of Channel Parameters
• Fading Characteristic
• Higher Order Channel Statistics
• Data Rate and the required Bandwidth
• Power Issues, BER and Equalization
• Noise and Interference

3
Sequence Of Presentation

• Channel Measurement and Simulation
• Channel Model
• Large Scale Fading Effect
• Small Scale Fading Effect
• Future Work
• Question and Answer Session

4
Channel Measurement and Simulation

• Experimental and Simulation Techniques
• The proposed design is a combination of two

• Calibration

Time Domain Measurement Technique

• Pulse Generation
• Resolution

• Transmission
• Antenna

• Multi-Path

• Detection

• Fading Statistics

5
Channel Measurement and Simulation
Vivaldi Antenna
CPW Monopole
Bow Tie
Patch Antenna
6
Large Scale Fading
Average Path loss as a function Transmitter and
Receiver separation
MMSE Technique is used to compute the average
path loss. Sample Variance is calculated and can
be added in the received power.
7
Large Scale Fading
8
Channel Characteristic
9
Channel Characteristic
50Psec
500 Psec
10
Small Scale Fading

• Multipath in the radio channel creates small
  scale fading.
• The Channel Delay Spread is measured to obtain
  the fading x-ties.
• Second Order Statistic can be obtained
• Bandwidth
• Data Rate
• BER
• Level Crossing and Fading Rate
• Coherence Bandwidth..

11
Small Scale Fading
12
Frequency Spectrum (Vivaldi Antenna)
13
Secondary Statistic
14
Small Scale Fading
15
Future Work and Relevance to Specknet

• Channel Sounding with appropriate sized antenna
  with..
• Different Scenarios (LOS, NLOS).
• Estimation of Noise Floor.
• Different Operating Environments with due
  consideration of material losses.
• With Higher data rates the channel become
  frequency selective.
• SNR and BER relation ship

16
Acknowledgment

• Mr Ian McGregor
• Mr Griogair Whyte