FIRST YEAR DSP EDUCATION IN THE CONTEXT OF ECE CURRICULUM REFORM Sally L. Wood Susan C. Kemnitzer [email protected] [email protected] National Science Foundation ENG/EEC 4201 Wilson Boulevard, Arlington, Virginia 22230 ABSTRACT courses [e.g. 6-9] were developed to meet some institutionally specific needs and some needs more general Over time DSP education has tracked the evolution and to the discipline. Programs have also been developed to growth of its theoretical foundations, hardware and bring DSP topics, especially audio and video, to high school implementation resources, and engineering education students [10,11]. context. First year DSP courses have often had dual More recently a wide variety of first year engineering objectives of both motivating students to consider EE courses, often multidisciplinary, have been proposed and through an interesting first course and laboratory experience implemented to address a number of issues from a variety of and also satisfying some part of the major curriculum perspectives, some of which may have conflicting requirements. Recent trends in engineering education and objectives. To better understand future directions of first curriculum reform may offer opportunities to include DSP year courses and the role that DSP will play, it is important content in the early curriculum in a more distributed manner to understand the changing contexts of technological rather than as a single course. Reformed EE programs may development, the dynamics and migration of engineering focus on multidisciplinary and integrated freshman departmental structures and curricula, new ideas about experiences in terms of design projects or specific context general restructuring of engineering education, the themes. This paper explores how DSP course content might expectations for the engineer of the future [12, 13], and the be integrated into first year experiences in this context and social perceptions of engineering [14]. explores implications with respect to concept continuity and The first attempts to move DSP from a senior level assessment. elective taken by a small number of engineering students to a lower division course for a much broader group of Index Terms— DSP education, first year, students addressed questions of whether or not it could be multidisciplinary course, complex systems, assessment done and then how it could be done using newly available hardware and development tools. Looking forward, the DSP community needs to address questions of why DSP should be in first year courses, what parts of DSP are most suitable for early introduction, what pedagogical purposes are served 1. INTRODUCTION by early introduction of DSP, how first year courses should Since the first Signal Processing Education Workshop in be evaluated, and how DSP will fit into future trends in 2000, a number of engineering programs have introduced engineering education. creative engaging first year courses either with a focus on digital signal processing (DSP) or with a broader focus that includes significant components with a DSP orientation. The widely adopted text, Signal Processing First [1] is an 2. MOTIVATIONS FOR FIRST YEAR DSP COURSES example of content selection and style for an introductory presentation of signal processing that does not have a long The content and style of digital signal processing in the prerequisite list and can be used for both electrical engineering curriculum has been tied closely to the current engineering majors and nonmajors. Courses based on the context of new theoretical methods and the current level of DSP First concept [e.g. 2-5] and first and second year development of enabling technologies for DSP 978-1-4244-3677-4/09/$25.00 ©2009 IEEE 425 Report Documentation Page Form Approved OMB No. 0704-0188 Public reporting burden for the collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden, to Washington Headquarters Services, Directorate for Information Operations and Reports, 1215 Jefferson Davis Highway, Suite 1204, Arlington VA 22202-4302. Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to a penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number. 1. REPORT DATE 3. DATES COVERED JAN 2009 2. REPORT TYPE 00-00-2009 to 00-00-2009 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER First Year DSP Education in the Context of ECE Curriculum Reform 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) 8. PERFORMING ORGANIZATION National Science Foundation,ENG/EEC,4201 Wilson REPORT NUMBER Boulevard,Arlington,VA,22230 9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES) 10. SPONSOR/MONITOR’S ACRONYM(S) 11. SPONSOR/MONITOR’S REPORT NUMBER(S) 12. DISTRIBUTION/AVAILABILITY STATEMENT Approved for public release; distribution unlimited 13. SUPPLEMENTARY NOTES See also ADM002264. Presented at the IEEE Digital Signal Processing Workshop (13th) and Signal Processing Education Workshop (5th) Held in Marco Island, Florida on 4-7 January 2009. Sponsored by ONR. 14. ABSTRACT Over time DSP education has tracked the evolution and growth of its theoretical foundations, hardware and implementation resources, and engineering education context. First year DSP courses have often had dual objectives of both motivating students to consider EE through an interesting first course and laboratory experience and also satisfying some part of the major curriculum requirements. Recent trends in engineering education and curriculum reform may offer opportunities to include DSP content in the early curriculum in a more distributed manner rather than as a single course. Reformed EE programs may focus on multidisciplinary and integrated freshman experiences in terms of design projects or specific context themes. This paper explores how DSP course content might be integrated into first year experiences in this context and explores implications with respect to concept continuity and assessment. 15. SUBJECT TERMS 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF 18. NUMBER 19a. NAME OF ABSTRACT OF PAGES RESPONSIBLE PERSON a. REPORT b. ABSTRACT c. THIS PAGE Same as 5 unclassified unclassified unclassified Report (SAR) Standard Form 298 (Rev. 8-98) Prescribed by ANSI Std Z39-18 implementation. Early DSP courses were upper division or course was needed for those majors as well. In either case it graduate electives with a strong mathematical emphasis and was possible to identify a set of topics with broad homework based on derivations and proofs. For a laboratory application that was appropriate for an introductory level a student might write a Fortran program to implement a class. This created both problems and opportunities for radix-2 FFT. articulation with the upper division options. Would an early Advances in semiconductor technology, processor DSP course be a prerequisite to a later elective course which architectures, development tools and software for might have room for more advanced content based on the computation and visualization fundamentally changed assumption of the prerequisite? Would the advanced commercial applications of DSP and resources available to elective just assume basic exposure to DSP in the same way educators. Instructors could reasonably include laboratory it assumes lower division exposure to calculus and experiments to complement theoretical lecture differential equations? Would different universities present presentations, and employers looked for graduates with different subsets in the early courses? some implementation experience, so most DSP courses Bringing DSP into the lower division, possibly as a adopted real-time laboratory components, often using audio core course, has implications about the changing relevance signals. of the topic to the overall EE curriculum, and assessment of In addition to better preparing students for the success should include that broader context. The early workforce, real-time signal processing laboratories with introduction of DSP puts digital discrete time concepts some audio examples could also improve students’ concept before continuous analog concepts and, like digital logic development and theoretical understanding. For example, courses, often puts design before analysis. The impact of when listening to the audio output from a speaker, it is easy this reordering has not been easy to define. Typical to distinguish a square wave from a pure sinusoid because assessments of individual classes consider the effects of the harsh sound of the square wave harmonics. As the measured over the time that the course is given. It is far fundamental frequency of the square wave is increased more difficult to determine the longer term effect of the while the signal is low pass filtered by speakers or the early introduction of DSP concepts on students’ human ear, it is easy to hear the harmonics of a square wave performance in the circuits and systems courses they take fade to leave a pure tone. This experience could help many later. Perhaps their progress is accelerated and later students more fully understand the concepts of Fourier electives can be more advanced. Perhaps their series representation and frequency selective filtering before understanding is deeper. Perhaps their comfort level is the mathematical derivations are clearly understood. higher due to earlier exposure. Initially the main drivers for moving a first DSP course The rapid evolution of implementation options in recent to the lower division included both pedagogy and advances years and a corresponding increase in implementation focus in technology. Traditionally DSP and other systems has further complicated the question of where DSP should electives, such as communications and control, were taken be positioned [18, 19] and what topics should be included in by juniors and seniors who had completed prerequisite a first DSP course. For example, increased throughput of a courses in circuits and linear systems. As hardware for real- digital signal processing system used to depend on more time processing became available with appropriate efficient sequential algorithms and increased processor development tools, the increased ease of implementing real- clock speed. Now increased throughput can be achieved time DSP laboratory experiments made complex projects with multiprocessor systems or massively parallel feasible and also allowed more entry level exploratory customized architectures using FPGAs. Development tools activities. In addition, progress in computational and may use high level programming languages, or block visualization tools with MATLAB [15] and Java applets diagram design, or hardware description languages. With [16, 17] provided additional tools for understanding both this wide variety of options there are many alternatives for a fundamental and advanced concepts. With these new tools it first year topic set. became possible to meaningfully teach some parts of the An implementation orientation also raises questions first DSP course to students who had not had the linear about the basic design units of DSP as well as the order in systems prerequisite courses. which concepts are introduced [20]. From the application Since it was possible to teach DSP in the lower perspective there can be debate about what topics are basic division, placement of a first course there could be justified entry level DSP topics and what topics outside of the in several ways. It could be argued that DSP covered a traditional DSP scope must also be included. For example, a basic core subject area and for that reason it should be taken course may combine DSP and other topics such as discrete by all electrical engineering students. It could also be mathematics or architecture. Some DSP may be required for argued that understanding the acquisition, use, limitations, instrumentation courses in other engineering majors using and processing of digitally acquired signals had become tools such as LabVIEW [21] for an introduction to actual fundamental to engineering in other disciplines such an and virtual instrumentation. mechanical, civil, or bioengineering, and an entry level DSP 426 A more recent motivation for moving DSP to the lower A second common factor in many first year programs is division has been to increase excitement about electrical an emphasis on system level design and development of engineering and to increase enrollment and retention. approaches to understanding and dealing with complex Declining interest in EE for the current generation of problems such as sustainable energy, environmental students has led to efforts to put more engaging hands-on monitoring, assistive devices for the disabled, or control of projects in the first year to balance the traditional core transportation systems. These types of projects are expected mathematics and science topics. Then students do not have to bring more perceived coherence to the curriculum that to wait until the upper division to do projects they find follows and to provide students with a sense of satisfaction interesting [e.g. 21, 22]. Assessments of first year courses and accomplishment. Assessments of improvement in from this perspective typically try to measure increased retention and pedagogical impact will lead to future student enthusiasm for the major or increased student development and modifications of these approaches. confidence or sense of purpose at the end of the course. These recent trends in engineering education and However, with the crowded curriculum for most curriculum reform may offer opportunities to include DSP engineering majors, a course that excites students about the content in the early curriculum in a more distributed manner major must also play a role in teaching concepts, rather than offering it as a single course. DSP modules may techniques, and technical understanding required for that become basic building blocks like other basic core concepts major to achieve the desired learning outcomes. These must Theme based ECE curriculum redesign can provide also be assessed. students with a more integrated understanding of the Although students may express satisfaction with a first DSP discipline. For example, in a Duke University reform effort course, other types of engaging first year courses have also the theme for the introductory and core courses is Integrated been successful. Multidisciplinary robotics courses and Sensing and Information Processing [27, 28]. DSP community based projects, for example, may include some components easily could be included in such a program at DSP in a broader context both the sensing and processing levels. Another approach to department level reform at the University of Utah [29] uses system-level design integrated into individual courses or 3. DEPARTMENTAL LEVEL REFORM FOR EE across multiple courses. Since most system-level design involves some data acquisition and processing, there is On a national scale electrical engineering curricula are potential to make DSP an important component. The currently adapting to rapidly changing technology and concept of a spiral curriculum structure [30] in ECE also changing demand for skills while engineering programs are proposes a more integrated curriculum with less traditional engaged in a variety of experiments to improve recruitment compartmentalization. and retention. This has led to proposed major restructurings of the traditional hierarchical delayed gratification curriculum and to attempts to align the curriculum more 4. ASSESSMENT OF STUDENT LEARNING closely with current and perceived requirements for engineering graduates who can compete in the future This wide variety of possible first year courses and the globalized workplace [12, 13, 14, 23]. possibilities of distributed teaching of DSP in Although individual institutions have unique contexts multidisciplinary first year courses or vertically integrated and have developed a variety of narrow and broad scale curricula raise challenging questions of how and when to do curriculum changes within their context, there are common assessments. Faculty seeking to improve student learning components in many of these new courses and curricula. In through course or curriculum modification need reliable an attempt to increase relevance and student interest, a metrics to assess the impact of the changes. The concept number of first year programs focus on a multidisciplinary inventory approach to a specific area was pioneered in engineering design projects in the context of a community physics [31] and a specific concept inventory for DSP has or social need. Project based learning has been widely been tested [32]. Typically these tests of concept adopted and programs with a community service focus, such understanding are administered at the beginning and end of as EPICS [ 24, 25], have been attractive to students. Other a class to help determine the impact of a change in course first year programs may focus on a more narrowly defined content, structure, or delivery such as active learning. The technical design challenge, but still have a multidisciplinary application of concept inventories should be explored in the approach. 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