The Cal Poly motto is "learn-by-doing". This
approach to learning is embraced in the Digital Signal Processing area where students design,
implement and test real-time DSP systems using industry standard equipment. Our
current DSP boards are all in the Texas Instruments 6000-series. This equipment provides not only a hands-on environment where students see theory
come into practice, but it also provides a learning experience with direct
on-the-job skills. Our DSP lab is actively used and is quite popular with
students.
Approximately 80 students per year take a senior
level technical elective in digital signal processing (EE419/459). A lab room
(20-135) is dedicated to
this course. Students design and implement numerous types of digital filters in
the lab. Design and analysis are accomplished with tools such as MatLab and
DaDisp. Implementation and testing are done using TI's EVM board with C6000
processor that is programmed in C. We have 8 PCs outfitted with
EVMs currently.
A final project in the Senior-Level course is
intended to bring to closure concepts involved in filter design and analysis.
This project is also intended to give students an appreciation for how DSP
modules can become part of a larger integrated system. In the final project,
students must first perform spectral analyses of signals in order to define
filter requirements. Students then design, implement and test filters using the
EVM. Project requirements are defined that would ultimately require equipment beyond just
the DSP to form a complete system. This encourages students consider
how a DSP could be integrated into an application.
In addition to the
Senior-Level course, we also offer a graduate-level course in Digital Signal
Processing (EE515). This
course covers advanced topics such as Optimal Filtering and Adaptive Filtering.
The 2-quarter Senior Project is a capstone experience
for CalPoly students. DSP-oriented projects are not uncommon and typically
involve a real-time implementation on our TI DSP boards. Recent projects include
Adaptive Filtering, Musical Effects, Audio Equalizer, Linear Predictive Coding
for Audio Compression, and more. Some projects have explored the use of
expansion circuitry and boards for the EVM which provide a second analog input -
this is critical for some algorithms, such as Adaptive Filtering. Masters
students also take advantage of our TI equipment. Two theses involving
correlation-based detection of spread spectrum signals are recent examples.
Some of the Senior Projects and Masters Theses use
the TI DSK board. This style of board sits outside a PC and is connected via
either serial or parallel port (depending on the model of the device). DSK's are
convenient for students, as they can check one out for
an extended period. These platforms are also a mechanism by which lab development can occur,
via Faculty members building upon the initial work of students - adding
appropriate refinements and documentation, for example. Lab development with the
DSK boards is an on going process, and these boards play a key role in our
future plans.
Housing DSKs in a clear Plexiglas case makes for a
novel learning experience when students are first introduced to DSP equipment.
This type of setup gives the user an explicit appreciation that processing is
DSP-based (there are no R-L-C elements present, just an arithmetic platform).
The impact of seeing the real-time DSP platform at work is all the greater when
the connection to the PC development platform is severed and the filter
continues to operate. This type of experience creates a more lasting impression
on students; as opposed to when processing occurs
("magically") within a PC enclosure.
The Cal Poly Electrical Engineering Department is
actively working on curriculum revision. This revision will likely include a new
lab in our introductory discrete-time systems course (one of the few
courses that does not already have a lab component). This would provide a
stronger introduction to the discrete domain, which is entirely appropriate - and
necessary - in our changing times. We are considering new lab facilities that
would allow us to bring "DSP to the masses" in this lab, possibly via the bench top
DSK-style of development environment.
Possible lab activities in this introductory course could include testing the
frequency response and transient response of FIR and IIR filters, and comparing
these results to theory. Some filter design could also be explored. Students
could study these filters by editing coefficient files, and
recompiling/downloading. This style of activity would be appropriate for the
students' experience level and available time to tackle the learning curve
associated with the development environment. The
external-style DSK boards are desirable for this new lab because they allow a single PC to
support several concurrent experiments (via an A/B switch, for example). The DSK-style is also advantageous
because of its standard PC interface. This improves flexibility, giving the DSK
equipment a longer productive lifetime as boards can make a transition to
upgraded PCs when available.
