In February 2002, the Federal Communications Commission (FCC) revised its Part 15 emission rules and allowed the use of a large section of the radio-frequency (RF) spectrum by commercial ultra-wideband (UWB) transmission devices. The restrictions imposed on these devices include a limit on the transmitted power spectral density of -41 dBm/MHz from 3.1 to 10.6 GHz and a minimum signal bandwidth of 500 MHz. The availability of such a wide bandwidth has enabled several new short-distance, low-power, high bit-rate applications for communication, ranging and location-finding. Industrial standards proposals for the use of the above bandwidth allow for very impressive throughput performance. However, since time-to-market is a major constraint, many of these standards use variants of well-known carrier-based communication methods.
This new FCC policy allows the public use of such a large spectrum for the first time. Thus it opens opportunities for fundamentally new research in wireless communications in topics such as radically new signaling methods and architectures, and their integrated circuit realization, in contrast with the traditional narrow-band approach of carrier-based modulation techniques.
Intellectual Merits: The PI proposes to use this unique opportunity to research highly efficient, integrated circuit implementations of transceivers for UWB radio applications. He will explore the trade-offs between the signaling and system level, and the architectural and integrated circuit implementation level. He proposes to investigate an implementation-friendly digital multi-carrier UWB signaling format that is expected to alleviate major issues with UWB communications, namely interference and multipath. He also plans to investigate a low-power interference detector which detects the presence of undesired signals in given frequency bands. The detector shares interference information with other transceivers and allows for a unique intelligent interference mitigation strategy. The interference detection strategy can be combined very well with the proposed signaling format, with minimal hardware cost or power overhead. These innovations are enabled by our proposed research efforts in the efficient implementation of transceivers in VLSI integrated circuits. The low RF output power-levels in UWB open the possibility to use current and future nanometer CMOS technologies and exploit the impressive operation speed they offer. He plans to develop a circuit implementation of the transceivers including such circuit blocks as broadband amplifiers, high linearity correlators and matched filters, high-speed D/A and A/D converters, and output buffers.
Broader Impacts: Communication technologies and more specifically wireless communication technologies play a prominent role in developing a broadly accessible cyber-infrastructure. UWB radio technology opens exciting new opportunities for applications and the proposed research on the realization of an efficient physical layer is crucial enabler towards applications.
The shortage of analog, mixed-signal, and RF integrated circuit designers, with in-depth knowledge of the communication systems aspects of the problem, has been a continuous challenge for the advancement of this field. Through research experiences and courses, his program will educate researchers and circuit designers with the cross-disciplinary skills to invent new design principles for integrated circuits in the context of the system in which they operate.
The program involves the collaboration of PIs at different institutions. It leverages the industrial expertise and research backgrounds of both PIs. It further offers unique opportunities for graduate and undergraduate students to interact with a broader research effort. To enhance the educational opportunities for students in this emerging field, new courses will be developed. For undergraduate students a research experience program is proposed that will offer research projects specifically designed to provide hands-on experience and extend their expertise.
