Synchronization in Synchronization in Digital CommunicationDigital Communication

By: Bader Al-Kandari and Josh MasonBy: Bader Al-Kandari and Josh Mason

Advisors: Dr. Thomas L. Stewart, Dr. In Advisors: Dr. Thomas L. Stewart, Dr. In Soo AhnSoo Ahn

The purpose of this project is the The purpose of this project is the development of a Quadrature development of a Quadrature Amplitude Modulation (QAM) signal Amplitude Modulation (QAM) signal communication system. communication system. MATLAB/Simulink simulation MATLAB/Simulink simulation environment, Code Composer Studio environment, Code Composer Studio Software (CCS) and two TI DSP Software (CCS) and two TI DSP boards are used to develop and to boards are used to develop and to implement the design. implement the design.

Project Proposal ContentsProject Proposal Contents

QAM OverviewQAM Overview Functional DescriptionFunctional Description Transmitter/Receiver Block DiagramsTransmitter/Receiver Block Diagrams Equipment/Standards/PatentsEquipment/Standards/Patents Preliminary ResultsPreliminary Results Schedule of Remaining WorkSchedule of Remaining Work Questions?Questions?

QAM OverviewQAM Overview

Quadrature Amplitude ModulationQuadrature Amplitude Modulation Sine (Quadrature) and Cosine (In-Sine (Quadrature) and Cosine (In-

Phase) CarriersPhase) Carriers 2-D plane with In-phase and 2-D plane with In-phase and

Quadrature AxisQuadrature Axis

QAM OverviewQAM Overview

4-QAM Data Constellation4-QAM Data Constellation

QAM OverviewQAM Overview

Higher order QAM - 16-QAMHigher order QAM - 16-QAM

Functional DescriptionFunctional Description

Binary Data/Input SignalsDSP

(Practical portion)

Host PC(Simulation and debugging)

Recovered Data/ Signals

Graphs in MATLAB environment

Functional DescriptionFunctional Description

InputsInputs• TransmitterTransmitter

Signals from a function generatorSignals from a function generator Stored DataStored Data

• ReceiverReceiver QAM signalQAM signal Stored DataStored Data

Functional DescriptionFunctional Description

OutputsOutputs• TransmitterTransmitter

QAM signalQAM signal

• ReceiverReceiver Recovered DataRecovered Data

Matlab/Simulink Data AcquisitionMatlab/Simulink Data Acquisition

Functional DescriptionFunctional Description

Modes of OperationModes of Operation

Transmitter – Real Time ModulationTransmitter – Real Time Modulation

Receiver – Real Time Demodulation Receiver – Real Time Demodulation

Transmitter Block DiagramTransmitter Block Diagram

X(t), Y(t) signal selection

ADC

Digital Filter(Raised-Cosine roll-off)

Digital Filter(Raised-Cosine roll-off)

X X

Σ

QA

M o

utpu

t

Sin(Wc*n) Cos(Wc*n)

DAC

Data

Transmitter Block DiagramTransmitter Block Diagram

Filters lower bandwidth requirementsFilters lower bandwidth requirements

Digital Carriers – Sampling effectDigital Carriers – Sampling effect

Adaptable for stored data inputsAdaptable for stored data inputs

Receiver Block DiagramReceiver Block Diagram

Binary QAM

X

X

Cos(W

l*t)

Sin

(Wl*

t)

Filter

Filter Integrator

Integrator

Phase Detector

Phase Detector

0.5 * X *[ cos(Wc – Wl)*t + cos(Wc + Wl)*t] + 0.5 * Y *[ sin(Wc – Wl)*t + sin(Wc + Wl)*t]

0.5 * X *[ sin(Wl – Wc)*t + sin(Wc + Wl)*t] +0.5 * X *[ cos(Wc – Wl)*t - cos(Wc + Wl)*t]

0.5 * X *[ sin(Wl – Wc)*t + sin(Wc + Wl)*t]

0.5 * X *[ cos(Wc – Wl)*t + cos(Wc + Wl)*t]

X*cos(Wc*t) + Y*sin(Wc*t)

Recovered signal I

Recovered signal Q

Receiver Block DiagramReceiver Block Diagram

Phase DistortionPhase Distortion• ChannelChannel

90 degree distortion = data error every time90 degree distortion = data error every time

• Digital Carrier – Sampling effectsDigital Carrier – Sampling effects Independent of channel distortionIndependent of channel distortion

0.5 * X *[ cos(Wc – Wl)*t + cos(Wc + Wl)*t] + 0.5 * Y *[ sin(Wc – Wl)*t + sin(Wc + Wl)*t]

EquipmentEquipment

Spectrum Digital TMS320C6713 DSK Spectrum Digital TMS320C6713 DSK

Agilent 33220A Function GeneratorAgilent 33220A Function Generator

Tektronix TDS 3012B 100MHz Tektronix TDS 3012B 100MHz OscilloscopeOscilloscope

SoftwareSoftware

Matlab/SimulinkMatlab/Simulink• Data GenerationData Generation• SimulationSimulation• System DesignSystem Design

Code Composer StudioCode Composer Studio• DSP Code CreationDSP Code Creation• DSP InterfacingDSP Interfacing

TMS320C6713 DSKTMS320C6713 DSK

TI c6713 DSPTI c6713 DSP• 225 MHz225 MHz

USB interfaceUSB interface AIC23 Audio Codec package AIC23 Audio Codec package

• 8 KHz, 32 KHz, 44.1 KHz, 48 KHz, and 96 8 KHz, 32 KHz, 44.1 KHz, 48 KHz, and 96 KHz KHz

• four 3.5 mm stereo audio jacks four 3.5 mm stereo audio jacks

Patents/StandardsPatents/Standards

Many patentsMany patents• Analog, DSP, FPGAAnalog, DSP, FPGA

No Specific StandardsNo Specific Standards• ANSI/SCTE 07 2000 ANSI/SCTE 07 2000

64-QAM, 256-QAM Digital Cable64-QAM, 256-QAM Digital Cable

• IEEE 802.11bIEEE 802.11b PSK Wireless NetworkingPSK Wireless Networking

Preliminary ResultsPreliminary Results

QAM Simulink DevelopmentQAM Simulink Development• 4-QAM Transmit/Receive4-QAM Transmit/Receive

DSP interfacing/testingDSP interfacing/testing• Digital filteringDigital filtering

Analog sourceAnalog source Data SourceData Source

4-QAM Simulink Testing4-QAM Simulink Testing

Simple TransmitterSimple Transmitter

4-QAM Simulink Testing4-QAM Simulink Testing

4-QAM Simulink Testing4-QAM Simulink Testing

4-QAM Simulink Testing4-QAM Simulink Testing

4-QAM Simulink Testing4-QAM Simulink Testing

DSP Filter TestDSP Filter Test

FIR FilterFIR Filter• Fpass 8 KHzFpass 8 KHz• Fstop 16 KHzFstop 16 KHz

8 KHz Square Wave Input8 KHz Square Wave Input

44.1 KHz Sampling Rate44.1 KHz Sampling Rate

DSP Filter TestDSP Filter Test

DSP Filter TestDSP Filter Test

Schedule of Remaining WorkSchedule of Remaining WorkPracticalPractical TheoreticalTheoretical

12/1/200512/1/2005 Proposal PresentationProposal Presentation Proposal PresentationProposal PresentationWinter BreakWinter Break Work on WebsiteWork on Website Work on Phase distortionWork on Phase distortion1/24/20061/24/2006 Fully Develop DSP I/O Fully Develop DSP I/O correctioncorrection1/31/20061/31/2006 w/ Matlab/Simulink w/ Matlab/Simulink 2/7/20062/7/2006 Begin Documentation Begin Documentation 2/14/20062/14/2006 Test/gather data ofTest/gather data of Finalize 4-QAMFinalize 4-QAM2/21/20062/21/2006 implemented 4-QAM implemented 4-QAM 2/28/20062/28/2006 Documentation/TutorialDocumentation/Tutorial Finish up any remainingFinish up any remaining3/7/20063/7/2006 WorkWork phase distortion problemsphase distortion problems3/21/20063/21/2006 8-QAM testing/data  8-QAM testing/data  3/28/20063/28/2006 gatheringgathering Begin work on 8-QAMBegin work on 8-QAM4/4/20064/4/2006 Documentation/TutorialDocumentation/Tutorial and 16-QAMand 16-QAM4/11/20064/11/2006 16-QAM testing 16-QAM testing 4/18/20064/18/2006 DocumentationDocumentation DocumentationDocumentation4/25/20064/25/2006 PresentationPresentation PresentationPresentation5/2/2006  5/2/2006  

Questions?Questions?