Ultra-Wideband PHY/MAC

Project Objectives:
Design and analysis of an ultra-wide band (UWB) physical layer (modem) and medium access control (MAC), optimized for short-range, super high-speed (~100’s of Mbps) applications. This project, aims to develop basic UWB radio technology via investigation of:

• UWB antenna characterization;
• Signal design for efficient UWB communications;
• UWB modem signal processing algorithms for matched filtering, interference cancellation, signal acquisition and timing, bit-rate adaptation, etc.;
• MAC protocols suitable for the short-range UWB service model;
• System simulation of multiple UWB transceivers in presence of other non-UWB interferers.

Technical Approach:
WINLAB’s UWB research program is currently being scoped in terms of the following activities:

• Antenna measurement for characterization and design
• PHY design & algorithms applicable to matched filtering, interference cancellation, synchronization, bit-rate adaptation, etc.
• Signal design for efficient UWB communications; PAPR, multi-path and multi-user interference, orthogonal and multi-rate signaling
• MAC protocol design aimed at short-range UWB service scenarios
• System simulation for detailed evaluation of UWB networks with realistic channel models, non-UWB interference, etc.
• Silicon implementation of UWB radios, in terms of analog RF, mixed signal and digital processing aspects
• System-level prototyping aimed at validating UWB in context of Infostations and/or sensor network applications

Technology Rationale:
UWB has recently emerged as an interesting and potentially significant candidate for next-generation wireless local-area, personal-area and sensor networks, particularly in scenarios which require robust scalable and uncoordinated operation. The FCC has recently established initial rules for UWB operation, thus paving the way for commercial applications of the technology during the next few years. WINLAB identified UWB as a strategic research topic in mid-2001, and is now focusing on the design of UWB radio links for short-range (~10 m) super-high speed (~100’s of Mbps) applications motivated by earlier work on the “Infostations” service model. Prior R&D and startup company activities on UWB have focused on low-med speed (~Mbps) at higher range (~100m+), but we believe that the true potential of UWB is for significant cost/performance improvements in short-range broadband access from an untethered computing & communication device to the network infrastructure. Near-term commercial applications include ne xt-generation Bluetooth, wireless USB, Infostations, etc., which in the longer term may be expected to migrate towards pervasive computing scenarios with large numbers of user devices and sensors. In the military context, high-bandwidth short-range connectivity enables many important capabilities such as wearable computers, reconfigurable tactical networks, mobile soldier to infrastructure links, ad-hoc sensor networks, etc.

Results to Date and Future Work Plan:
WINLAB faculty are currently working on:

• wideband antenna measurements for short-range UWB access;
• UWB physical layer design concepts aimed at simplified implementation of key components such as signal design, adaptive matched filter, RAKE receivers and fast synchronizer;
• design and evaluation of potential UWB MAC protocols, taking into account prior work done on next-generation personal-area-networking standards (e.g. IEEE 802.15.3).

Work on these topics is currently at the design and simulation stage, in part supported by NSF funding and in collaboration with Princeton University and New Jersey Institute of Technology. Currently, we plan to ramp up this work to a larger UWB technology development and prototyping project further supported by appropriate Govt. funding. We are open to research collaboration inquiries from companies and other Universities interested in the UWB focus outlined above.