Page 23 - Fundamentals of Communications Systems

Preface xxi

four years of working I used all of my graduate classes in solving communi-
cation problems and was a key engineer in a team that built and field tested
a sophisticated wireless modem. I was hooked by communications engineer-
ing: It is a field that has a constant source of problems, a well-defined set of
metrics to be used in problem solving, and a clear upperbound (due to Claude
Shannon) to which each communication system could aspire.
2. Arrogance. I started my academic career, after being reasonably success-
ful while working in industry, with the feeling that I knew a great deal. I
was convinced that my way of looking at communications was the best and I
started teaching as such. I found the textbooks available at the time to have
inadequate coverage of the complex envelope representation of bandpass sig-
nals and bandpass noise and other modern topics. Hence my writing career
started by preparing handouts for my classes on these topics. I quickly got
up to 100 pages of material.
3. Humbled but Learning. It was not too long after starting to teach and
direct graduate student research that I came to the realization that the field
of communications was a mighty river and I had explored only a few fairly
minor tributaries. I came to realize I did not know much and still needed to
learn much. This realization began to be reflected in my teaching as well. I
branched out and learned other fields and reflected my new understanding in
my teaching methods and approaches. Much to my students’ chagrin, I often
used teaching as a method to explore the boundaries of my own learning. This
resulted in many poorly constructed homework problems and lectures that
were rough around the edges. As I am not very bright, when I synthesized
material I always had to put it into my own notation to keep things clear in
my own mind. After these bouts with new material that were very confusing
for my students, I often felt guilty and wrote up notes to clarify my ramblings.
Soon I was up to 200 pages of material on digital communications. As I would
discover later these notes, while technically correct, were agonizingly brief
for students and lacked sufficient examples to aid in learning.
4. Cruise Control. I soon got to the point where I had reasonable notes and
homework and my family and professional committments had grown to the
point where I needed not to focus so much on my teaching and let things run
a bit in cruise control. During this time I added a lot of homework and test
problems and continued to write up and edit material that was confusing to
students. My research always seems filled with interesting side issues that
make great homework problems. I started the practice of keeping a note book
of issues that have come up during research and then tried to morph these
issues into useful homework problems. Some problems were successes and
some were not. In 2002, I was up to about 300 pages.
5. Well I have 300 Pages . . . At the point of 300 pages I felt like I turned a
corner and had a book almost done and started shopping this book around
to publishers. My feeling was that there was not much left to complete and
once I signed a contract the book would appear in 6 months. This writing