7/28/2019 Fifsfsfsfnal Report Slides

1/15

Implementation of OFDM Transmitterbased on the IEEE 802.16d Standard

Presented by:Altamash Janjua, Umar Chohan

Supervisors:

Dr. Brian L. Evans and Mr. Ian Wong

Technical TA:

Mr. Youngok Kim

Date: 2nd December, 2004

7/28/2019 Fifsfsfsfnal Report Slides

2/15

Why is it Important to You?

Tremendous Growth ofWirelessCommunications

Wireless MetropolitanArea Networks (WMANs)

Future Projects in the

Industry www.gettyimages.com

7/28/2019 Fifsfsfsfnal Report Slides

3/15

Presentation Organization

Introduction

Transmitter Block Diagram IEEE 802.16d Standards

Transmitter Implementation

Design Testing and Validation Budget Constraints and Safety Features

Future Recommendations

Conclusion

7/28/2019 Fifsfsfsfnal Report Slides

4/15

Signals and Modulation

Continuous-time andDiscrete-time signals

Modulation : Carrier

Amplitude and/or

Frequency

t

x(t)

http://www.ece.utexas.edu/~bevans

7/28/2019 Fifsfsfsfnal Report Slides

5/15

What Is Orthogonal Frequency Division

Multiplexing (OFDM)?

Multi-carrier Amplitude modulation

scheme Each Carriers amplitude is modulated

Well-suited for Wireless Communication

www.iec.org/online/ tutorials/ofdm/topic04.html

Amplitude

Frequency

http://www.iec.org/online/tutorials/ofdm/topic04.htmlhttp://www.iec.org/online/tutorials/ofdm/topic04.html

7/28/2019 Fifsfsfsfnal Report Slides

6/15

How OFDM works?

Parallel Data Streams

Data Encoding is based onAmplitude Modulation

Multiple Carriers are combinedthrough the Fourier Series

Computed by Inverse FastFourier transform

4-QAM modulation

7/28/2019 Fifsfsfsfnal Report Slides

7/15

Our Simple Transmitter Block Diagram

Channel

Serial

To

Parallel

Encoding

Bank

IFFT Parallel

To

Serial

Cyclic

PrefixSerial

Data

Source

7/28/2019 Fifsfsfsfnal Report Slides

8/15

Transmitter based on the IEEE 802.16d

Standard

Upcoming Standard

for Wireless

Metropolitan Area

Networks (WMANs)

Specifications Used

256 FFT

56 guard carriers

16- QAM

Pilots and Guards

7/28/2019 Fifsfsfsfnal Report Slides

9/15

Transmitter Implementation

National Instruments Lab VIEW FPGA

VHDL and Lab VIEW programming

One Main Virtual Instrument (VI)

16-QAM Encoding Bank

256 point Complex IFFT core developed byXilinx Inc.

Cyclic Prefix Module

7/28/2019 Fifsfsfsfnal Report Slides

10/15

Testing and Validation

Individual Modules Tested through SoftwareSimulations

Developing a Host PC VI for the Testing offinal Hardware

Sample test results provided in the IEEE802.16d Standard

7/28/2019 Fifsfsfsfnal Report Slides

11/15

Safety Precautions

Fundamental Canon of

Engineering:

Hold Paramount Public Health

and Safety

Repeated Design Testing for

Functional Verification and

Robustness

Additional Indicators for Warnings

www.gettyimages.com

7/28/2019 Fifsfsfsfnal Report Slides

12/15

Budget Constraints

No Purchases Involved

Hardware and Software

Provided by Supervisors

Time-Consuming

Currently testing the designwww.gettyimages.com

7/28/2019 Fifsfsfsfnal Report Slides

13/15

Future Transmitter Implementations

Conventional Field

Programmable GateArrays

Digital Signal

Processors

Application Specific

Integrated Circuits www.gettyimages.com

7/28/2019 Fifsfsfsfnal Report Slides

14/15

Acknowledgements

Supervisors:

Dr. Brian L. Evans Mr. Ian Wong

Technical Teacher Assistant: Mr. Youngok Kim

7/28/2019 Fifsfsfsfnal Report Slides

15/15

Conclusion

Thank You!!

Questions??

www gettyimages com