One of the major goals of modern communications is to develop a system that provides users high-speed ubiquitous access to information. Such a system requires a wireless component; however, because of the limited amount of bandwidth available and the signal fading due to the multipath inherent to the wireless environment, the wireless component can be the bottleneck of the system. Thus, the communications research community is called upon to provide focused research on bandwidth efficient communications over multipath fading channels and to educate students so that they have the necessary skills to contribute to this and future systems. As detailed below, this project is addressing these issues through: (1) advances in coded modulation for high-speed wireless systems, (2) a comparison of system architectures for the physical layer of high-speed wireless systems, (3) broadly applicable innovations in the instruction of students, and (4) a program of undergraduate research in communication theory.
The two main architectures that are being considered for future high-speed wireless communication systems are a coded single-carrier system employing a decision feedback equalizer (DFE) at the receiver and a coded orthogonal frequency division multiplexing (OFDM) system. In this project, the problem of designing coded modulation for the OFDM system is being formally developed. By viewing this problem in the more general framework of frequency domain coded modulation (FDCM), design rules are being developed that lead to systems that can efficiently tradeoff complexity for improved bit error probability and amplifier efficiency relative to traditional OFDM systems. Furthermore, this project is analyzing the utility of the resulting systems as a hybrid between coded single-carrier systems employing a DFE and coded OFDM systems; this provides a unified comparison of the most widely considered system architectures for high-speed wireless communications. The educational portion of this project employs three complementary methods that strive to foster student learning through innovations that supplement traditional classroom instruction. The first method will be the continuation of the introduction of supplements that support active learning in traditional courses, such as the introduction of games of chance for course points in an undergraduate probability class. The second method will be the development of a capstone wireless communications course that will allow graduate students and advanced undergraduates to integrate their knowledge in various communication system components in a team-oriented environment that stresses overall system performance. Finally, the third method will be the continuation of a funded undergraduate research program, which aids promising undergraduate engineers by providing one-on-one attention in an active research environment.
