SPACETIME Coding

1
Introduction
SPACE-TIME Coding Group GREY Karl
Gerhardsson Anders Carlson Thomas
Karlsson Fredrik Hansson Leopold
Roos Stefan Uppgård
2
Overview

• Overview
• What is the problem?
• A solution
• What is Space-Time coding?
• Our Implementation
• Results Conclusions

3
Problem Definition
The problem is fading
Overview What is the problem? A
solution What is Space- Time coding? Our
Implementation Results Conclusions
4
Approach
Solution is diversity
Overview What is the problem? A
solution What is Space- Time coding? Our
Implementation Results Conclusions
5
Approach2
A possible solution Space diversity on the
downlink
Overview What is the problem? A
solution What is Space- Time coding? Our
Implementation Results Conclusions
6
What Is Space-Time Coding?
Alamouti Space-Time Code
Overview What is the problem? A
solution What is Space- Time coding? Our
Implementation Results Conclusions
Two transmitters 2x1 System
7
Alamouti Space-Time Code
What Is Space-Time Coding?
Overview What is the problem? A
solution What is Space- Time coding? Our
Implementation Results Conclusions

• Transmitted signals are orthogonal gt
  Simplified receiver
• Redundance in time and space gt Diversity
• Equivalent diversity gain as maximum ratio
  combining gt Smaller terminals

8
Overview
Overview What is the problem? A
solution What is Space- Time coding? Our
Implementation Results Conclusions
9
Our Implementeation
Input data to transmitter
Overview What is the problem? A
solution What is Space- Time coding? Our
Implementation Results Conclusions
10
The Model
Alamouti encoding Upsampling
Overview What is the problem? A
solution What is Space- Time coding? Our
Implementation Results Conclusions
11
The Model
Pulsshaping
Overview What is the problem? A
solution What is Space- Time coding? Our
Implementation Results Conclusions
12
The Model
Carrier frequency modulation
Overview What is the problem? A
solution What is Space- Time coding? Our
Implementation Results Conclusions
13
Results
Received signal
Overview What is the problem? A
solution What is Space- Time coding? Our
Implementation Results Conclusions
14
Results
Trigger correlation Frequency estimation
Overview What is the problem? A
solution What is Space- Time coding? Our
Implementation Results Conclusions
!
15
The Channel
Down conversion Lowpass filtering
Overview What is the problem? A
solution What is Space- Time coding? Our
Implementation Results Conclusions
16
The Receiver
Frequency offset compensation
Overview What is the problem? A
solution What is Space- Time coding? Our
Implementation Results Conclusions
17
The Receiver
Synchronization
Overview What is the problem? A
solution What is Space- Time coding? Our
Implementation Results Conclusions
18
The Receiver
Sampling
Overview What is the problem? A
solution What is Space- Time coding? Our
Implementation Results Conclusions
19
The Receiver
Channel estimation
Overview What is the problem? A
solution What is Space- Time coding? Our
Implementation Results Conclusions
20
The Receiver
Combination Detection
Overview What is the problem? A
solution What is Space- Time coding? Our
Implementation Results Conclusions
21
Overview
Overview What is the problem? A
solution What is Space- Time coding? Our
Implementation Results Conclusions
22
Results
Simulation results
Overview What is the problem? A
solution What is Space- Time coding? Our
Implementation Results Conclusions
BER
SNR
23
Conclutions
Experimental results
Overview What is the problem? A
solution What is Space- Time coding? Our
Implementation Results Conclusions