Transcript Project in EE 545 Digital Communications

Integration of System
Design and Standard
Development in Digital
Communication Education
Xiaohua(Edward) Li
State University of New York at
Binghamton
Contents
 Introduction
 SAM project in digital communications
 Technical standard of SAM
 Conclusions
Introduction
 Digital communications education should



teach theory with a systematic view
use MATLAB projects to strengthen the
systematic view
develop practical system design experience
 Traditional ways of teaching may not perform
well enough
Introduction
 Our approach: joint theory, system design
and technical standard drafting
 Objectives:




Integrate theory with hands-on experience
Cost effective: computers only
Convenient: Matlab programming only
Competitive: drafting standards
Design of the SAM Project
 SAM: soft acoustic modem

a modem with PC and MATLAB
 Overview:
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


Phase 1: baseband transmission
Phase 2: passband transmission (wireline)
Phase 3: passband with coding (wireless)
Modem standard discussion and draft
 Work of students

demonstration, presentation, standard draft
The SAM Project (1)
 Phase I. Baseband system design
 Theory: data packet, pulse shaping, synchronizations
 Hardware: one PC
 Software: MATLAB
The SAM Project (2)
 Phase II. Passband wired transmission
 Theory: modulation/demodulation, synchronization
 Hardware: one or two PC
 Software: MATLAB
The SAM Project (3)
 Phase III. Wireless modem
 Theory: wireless, SNR, channel coding/decoding
Encoder
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XOR
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reg 0 reg 1 reg 2
S2

Hardware: two PCs
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The SAM (4). Software: MATLAB
The SAM Project (5)
 Typical transmitter and receiver block diagrams
Start Transmitter
Transmit
Sample for
1 kHz carrier
Assess Bit Error
Generate
random
message
Format message
with Barker and
Training Sequence
Convolutional encode
message
Modulate signal
with
1 kHz carrier
Pulse shape entire
signal
Record Waveform upon detection of
1 kHz carrier signal
Convolutional decode
Differentially
encode entire
signal
Frame Synchronize
using Barker
Demodulate
signal
Time synchronize and
sample
 Simulation results of one student group
Differentially
decode
Technical Standard Activity
 Technical standard
 Provide design guide and inter-operability
 Encourage competition
 Approaches for drafting standards:
 Only design objective is assigned
 Students are free to choose techniques
 Perform regular discussion to define common
parameters
 Each group draft a standard, among which
the most competitive one is recommended
Conclusions
 Project that stimulates students’ interest





Use practical design projects which involve
both software and hardware
Use tools which are under students’ control
Introduce competitions
Make it challenging by leaving questions open
Draft standards instead of writing ordinary
reports