Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs)

1. Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs) Submission Title: [Compromise for UWB Interoperability – PHY Overview] Date Submitted: [20 February, 2004] Source: [John McCorkle] Company [Motorola, Inc] Address [8133 Leesburg Pike] Voice:[703-269-3000], FAX: [703-249-3092], E-Mail:[john@xtremespectrum.com] Re: [IEEE 802.15.3a Call For Intent to Present for Ad-Hoc Meeting] Abstract: [This document provides an overview of a proposed Common Signaling Mode that would allow the inter-operation or MB-OFDM and DS-UWB devices.] Purpose: [Promote further discussion and compromise activities to advance the development of the TG3a Higher rate PHY standard.] Notice: This document has been prepared to assist the IEEE P802.15. It is offered as a basis for discussion and is not binding on the contributing individual(s) or organization(s). The material in this document is subject to change in form and content after further study. The contributor(s) reserve(s) the right to add, amend or withdraw material contained herein. Release: The contributor acknowledges and accepts that this contribution becomes the property of IEEE and may be made publicly available by P802.15. McCorkle, Motorola

2. Talking with each other: Basic Requirements • Each class of UWB devices (MB-OFDM or DS-UWB) needs a way to send messages to the other type • MB-OFDM  DS-UWB • DS-UWB MB-OFDM • Even better, design a common signaling mode that can be understood by either class of devices • Goal: Minimize additional complexity for each type of device while enabling this extra form of communications • Use existing RF components & DSP blocks to transmit message to “other-class” devices • Also need to support a low-complexity receiver • Lower rate mode could be acceptable if it can be used to provide robust control functions McCorkle, Motorola

3. Interoperability Signal Generation • One waveform that would be straightforward for either class of device ia a BPSK signal centered in the middle of the “low band” at ~ 4GHz • Such a signal could be generated by both MB-OFDM and DS-UWB devices using existing RF and digital blocks • MB-OFDM device contains a DAC nominally operating at 528 MHz • A 528 MHz BSPK (3 dB BW) signal is likely too wide for MB-OFDM band filters • DAC an be driven at slightly lower clock rate to produce a BPSK signal that will fit the MB-OFDM Tx filter • Result is a 500 MHz wide BPSK signal that a DS-UWB device could receive & demodulate • DS-UWB device contains a pulse generator • Use this to generate a 500 MHz BPSK signal at lower chip rate • This signal would fit MB-OFDM baseband Rx filter and could be demodulated by the MB-OFDM receiver McCorkle, Motorola

4. MB-OFDM & DS-UWB Signal Spectrum with CSM Compromise Solution MB-OFDM (3-band) Theoretical Spectrum Relative PSD (dB) Proposed Common Signaling Mode Band (500 MHz bandwidth) DS-UWB Low Band Pulse Shape (RRC) 0 -3 -20 3432 3960 4488 Frequency (MHz) 3100 5100 FCC Mask McCorkle, Motorola

5. Conclusions • The creation of a common signaling mode will allow co-existence and interoperability between DS-UWB and MB-OFDM devices • A Common Signaling Mode is described that: • Requires minimal additional cost/complexity in MB-OFDM & DS-UWB • Achieves desired data rates and robust performance • Prevents coexistence problems for two different UWB PHYs • Provides interoperability in a shared piconet environment McCorkle, Motorola