Senior Capstone Project Integration of Matlab Tools for DSP Code Generation

Senior Capstone Project

Integration of Matlab Tools for DSP Integration of Matlab Tools for DSP Code GenerationCode Generation

ECE DepartmentMarch 2nd, 2006

Team Members: Kwadwo Boateng and Charles Badu

Advisors: Professor Thomas Stewart and Dr Inn Soo Ahn

Project OutlineProject Outline Project Summary Current Status

Filter Implementation Modulation Schemes

Future Work Questions

PROJECT SUMMARYPROJECT SUMMARY Integrate Matlab tools with code composer studio 3.1 software to

generate C-code on DSP board (TMSC6713DSP board (TMSC6713) Integration process will involve Filter implementation and

Modulation schemes Filters and Modulation schemes (SPD) will be designed in

Simulink and verified experimentally on an oscilloscope Applications of SPD in industry will be examined S-block functions not found in Simulink will be generated and

called as subroutines. (MEX files) SPD executed on DSP board via Mat-lab M file or Simulink block

diagrams Ultimate goal is to produce User ManualUser Manual for DSP and

Communication Theory Students.

DSP BOARD (FEATURES)DSP BOARD (FEATURES)

Signal Processing Description

Host PC with Matlab

Development Tools

Simulink

Code Composer

studio (CCS) IDE

D.S.P boardTMS320C6713

Output file

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Code from Simulink Block Diagram

Figure 1: High-level system block diagram

SYSTEM BLOCK DIAGRAMSYSTEM BLOCK DIAGRAM

FIR Filter Design and ImplementationFIR Filter Design and Implementation

NOTCH FilterFilter that passes most frequencies unaltered, but attenuates those in a narrow range to very low levels

Given Equation:

H(Z)=h0+h1z-1 + h2z-2 2 poles at origin which corresponds to Z2

2 zeros 45 degrees from the origin

Design of Filter given formulae for H(z)Design of Filter given formulae for H(z)A Bandpass filter has transfer Function

(Z-ejpi/4)(Z-e-jpi/4)

H(z)= --------------------

Z2

Solve to get coefficients

Num: [1 -1.41421 1]

Den: [1 0 0] fa=fd*fs

fd=Digital Frequency fa=Analog frequency fs=Sampling frequency

Choosing fs= 8000Hz fd=1/8 ( Ranging between -.5 to .5)

fa= 1000Hz

Mat-lab results:Mat-lab results:

0 500 1000 1500 2000 2500 3000 3500 40000

0.5

1

1.5

2

2.5

3

3.5frequency response

NOTCH FILTER DESIGNNOTCH FILTER DESIGN

H(Z)=h0+hzH(Z)=h0+hz11-1-1 + hz + hz22

-2-2

FIR FILTER EXPERIMENTAL RESULTSFIR FILTER EXPERIMENTAL RESULTS

CommunicationCommunication SystemsSystems

Figure 1-1: The Fundamental Model of Communication

Modulation SchemesModulation Schemes• Amplitude Modulation (AM)• Frequency Shift Keying (FSK)• Double-Sideband Suppressed Carrier (DSB-SC)• Binary Phase-Shift Keying(BPSK)• Quadrature Amplitude Modulation(QAM)

Amplitude Modulation (AM)Amplitude Modulation (AM)

• Amplitude Modulation: the amplitude of a carrier signal is varied with respect to an input modulation signal to convey data.

• Applications: commonly used at radio frequencies and was the first method used to broadcast commercial radio.

• Modeled in project to transmit and receive speech signals.

Envelope Detector CircuitsEnvelope Detector Circuits

AM Experimental Results AM Experimental Results

AM Simulation Results AM Simulation Results

Frequency shift keying (FSK) is the most common form of digital modulation in the high-frequency radio spectrum

Used to send information between digital equipment like teleprinters and computers.

Data is transmitted by the frequency of a carrier in a binary manner to one or the other of two discrete frequencies.

Frequency Shift Keying (FSK)Frequency Shift Keying (FSK)

(FSK) Transmitter(FSK) Transmitter

Signal GenerationSignal Generation

FSK ReceiverFSK Receiver

Test Square waveTest Square wave

FSK Output Signal FSK Output Signal

Double-Sideband Suppressed Carrier Double-Sideband Suppressed Carrier

Double-sideband suppressed-carrier transmission (DSB-SC): transmission in which:

• (a) frequencies produced by amplitude modulation are symmetrically spaced above and below the carrier frequency

• (b) the carrier level is reduced to the lowest practical level, ideally completely suppressed.

DSB-SC TransmitterDSB-SC Transmitter

DSB-SC ReceiverDSB-SC Receiver

DSB-SC Receiver DSB-SC Receiver

• Phase-shift keying is a digital modulation scheme that conveys data by changing the phase of a reference signal (carrier wave) and BPSK is the simplest form of phase-shift keying.

• Generated the same way as a DSB-SC, but m(t) is a unipolar data signal

• Demodulated using a Costas loop

Binary Phase-Shift Keying Binary Phase-Shift Keying

Costas Phase-Locked LoopCostas Phase-Locked Loop

BPSK Simulation ResultsBPSK Simulation Results

Modulation Schemes QUADRATURE AMPLITUDE MODULATION (QAMQUADRATURE AMPLITUDE MODULATION (QAM))

Combination of : Amplitude Modulation (AM) Phase shift Keying (PSK)

Phase and Amplitude are Varied

Overcome constraints of complex AM or PM Transmits more bits per second Makes use of minimum bandwidth

GENERAL QAM TRANSMITTER

S(t)=X(t)CosWct - Y(t)SinWctS(t)=X(t)CosWct - Y(t)SinWct

Wc=2pifcWc=2pifc

QAM TRANSMITTER

S(t)=X(t)CosWct - Y(t)SinWctS(t)=X(t)CosWct - Y(t)SinWct

Wc=2pifcWc=2pifc

SIMULATION RESULTS OF QAM TRANSMITTER

EXPERIMENTAL RESULTS FOR QAM TRANSMITTER

QAM RECEIVER

Recovering Signals for Real X (t) & Quadrature Y (t)

MODIFIED DEMODULATORMODIFIED DEMODULATOR

SIMULATION RESULTS SIMULATION RESULTS FOR RECEIVER & TRANSMITTER FOR RECEIVER & TRANSMITTER

EXPERIMENAL RESULTS FOR TRANSMITTEREXPERIMENAL RESULTS FOR TRANSMITTER

EFFECTS OF CAPACITOR COUPLING

EFFECTS OF CAPACITOR COUPLING

PROOFING EFFECTS OF CAPACITOR COUPLINGPROOFING EFFECTS OF CAPACITOR COUPLING

EXPERIMENAL RESULTS FOR CAPACITOR COUPLINGEXPERIMENAL RESULTS FOR CAPACITOR COUPLING

Future WorkFuture Work

• Implement Costas Phase-Locked Loop on DSP board

• Work on Frequency Division Multiplexing (FDM)

• Orthogonal Frequency Division Multiplexing (OFDM)

• FM Stereo System

Questions ??Questions ??

THE GRAND ARRIVAL!!!