Asee peer logo

Fixed Point Dsp Implementation: Advanced Signal Processing Topics And Conceptual Learning

Download Paper |


2007 Annual Conference & Exposition


Honolulu, Hawaii

Publication Date

June 24, 2007

Start Date

June 24, 2007

End Date

June 27, 2007



Conference Session

Special Session on Fixed-Point Education

Tagged Division

Computers in Education

Page Count


Page Numbers

12.752.1 - 12.752.12



Permanent URL

Download Count


Request a correction

Paper Authors


Wayne Padgett Rose-Hulman Institute of Technology

visit author page

Wayne T. Padgett received his Ph.D. from Georgia Institute of Technology in 1994. He has been teaching digital signal processing and related courses at Rose-Hulman Institute of Technology for 12 years. He is a member of ASEE, a senior member of the IEEE, and is on the IEEE Signal Processing Society’s Technical Committee on Signal Processing Education.

visit author page

Download Paper |

NOTE: The first page of text has been automatically extracted and included below in lieu of an abstract

Fixed-Point DSP Implementation: Advanced Signal Processing Topics and Conceptual Learning


In this paper a description of a unique fixed point systems course, including a list of topics, a description of labs, and a discussion of the focus on a course project. The course has run four times using simulation environments to promote analysis and visualization. The content of the course has made it apparent that there are numerous linkages to advanced signal processing topics, and these are described. The course has also led to the initiation of an educational experiment using the Signals and Systems Concept Inventory (SSCI) to measure how two very different electives affect student understanding of basic concepts. The experiment compares the fixed point course which is very lab oriented, to a theoretical elective. Preliminary results are described. Work to develop a course text and lab materials is described as part of an effort to promote the adoption of fixed point material widely in electrical and computer engineering curricula.


Fixed-point implementation issues in digital signal processing (DSP) are not widely taught or deeply covered in most U.S. undergraduate (or graduate) curricula. There seems to be a perception among faculty that fixed-point implementation is difficult to tie to theory, and not important for advanced work in the field. However, the author’s experiences show that industrial practitioners rely heavily on fixed-point implementation skills, and that many opportunities exist to link a fixed-point implementation course to advanced signal processing topics. The author has taught a fixed-point system design course four times, and each time the need to draw on advanced topics has become more obvious.

Course Description

The course is called DSP System Design, not Fixed-Point Algorithm Development, because the only way to give students adequate experience with the tradeoffs and performance issues involved is to build the course around a project. Learning to measure, specify, and adjust the system’s performance is a critical element of the course, and it drives the students to deepen their understanding of the fixed-point effects. Although many possible projects could serve well, the course has been based on an SSB communication system which takes input speech at an 8 kHz sample rate and then raises the sample rate to 96 kHz (12x) for SSB modulation at 40 kHz (actually four channels are implemented eventually). The receiver removes out of band interference, demodulates the signal, and then reduces the sample rate back to 8 kHz. The basic design is then extended to operate at four channel frequencies with minimal inter-channel interference, and subject to various (conflicting) performance criteria such as speech quality, SNR, and computational complexity.

In the past three offerings, all of the course project work has been done in MATLAB, primarily using the Fixed Point Toolbox functions. All of the fixed-point system development is done as

Padgett, W. (2007, June), Fixed Point Dsp Implementation: Advanced Signal Processing Topics And Conceptual Learning Paper presented at 2007 Annual Conference & Exposition, Honolulu, Hawaii. 10.18260/1-2--2545

ASEE holds the copyright on this document. It may be read by the public free of charge. Authors may archive their work on personal websites or in institutional repositories with the following citation: © 2007 American Society for Engineering Education. Other scholars may excerpt or quote from these materials with the same citation. When excerpting or quoting from Conference Proceedings, authors should, in addition to noting the ASEE copyright, list all the original authors and their institutions and name the host city of the conference. - Last updated April 1, 2015