UWB Radio: Issues and Opportunities Jim Lansford, Ph.D. CTO, Alereon jim.lansford@alereon.com We re not going to talk about the Rose Bowl today!
Agenda 2 Issues Is regulatory really solved? What about standards? What are the remaining design challenges? Opportunities What are the research opportunities? What about 60GHz? Wrapup
Is regulatory really solved? 3 We are getting closer US, Japan, and Korea are done but DAA is an open issue Europe is still a problem China is in process Detect and Avoid (DAA) is required, but not defined! -40-45 - 41.3 dbm/mhz USA CEPT Japan - 41.3 dbm/mhz Korea -50 UWB EIRP Density, dbm/mhz -55-60 -65-70 -75 1.99 1.61 3.1 10.6 9 3.4 4.8 7.25 10.25 3.1 4.95 6 7.1 10.5-80 -85 2.7-90 -95 1.61 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 6.5 7.0 7.5 8.0 8.5 9.0 9.5 10.0 10.5 11.0 11.5 12.0 12.5 Frequency, GHz
What about standards? 4 IEEE is dead But it doesn t matter! The race is essentially over There is a standard WiMedia s Multiband OFDM WiMedia MB-OFDM was ratified as ECMA-368/369 in Dec 2005 ISO standard by the end of the summer Recent WiMedia interop tests had six different interoperable chipsets not FPGAs, not second source, but true independent solutions Certified Wireless USB uses ECMA-368/369 Products will go into production this summer Bluetooth has adopted WiMedia UWB Above 6GHz bands only Software layers above the WiMedia MAC Will enter market in 2007
What are the remaining design challenges? 5 Note: I m only going to talk about WiMedia (MB-OFDM) This is a race to the bottom Lowest power Lowest cost (this does not imply single die reasonable people may disagree) Hardware needs some evolution Better ADCs 6 bits, low power >528MHz sampling Optimized FFT and Viterbi engines pretty straightforward 90nm solutions have the potential to be pretty good! As usual, software is now important Microsoft, Intel, etc. are engaged Microsoft is way ahead of the curve in wusb compared to wired USB Vista support is coming! The DAA goals are still not clear, so we will continue to have to put lots of general hooks in place
WiMedia/Certified Wireless USB/UWBoBT 6 Detect Mixer & Filter 90 Mixer & Filter ADC AGC DAC Filter/ Decimate Interp. /Filter FFT/ IFFT Despread Demap Deinterleave Depuncture Chan Est CFO Equalize Spreading Mapping Interleave Puncture Viterbi Convo - lutional Coder MAC/PHY Interface RF Baseband/MAC 5mm x 5mm 10mm x 10mm
WiMedia MAC is flexible 7 The WiMedia MAC can support many protocol stacks over the same radio &/or &/or &/or IP PAL PAL PAL WiNET PAL: Protocol Adaptation Layer WiMedia MAC Convergence Architecture (WiMCA) WiMedia MAC WiMedia PHY (MB-OFDM)
Here s where we re headed. 8 Coming to a retail store near you this fall!
What are the research opportunities? 9 Detect and Avoid (DAA) Better power spectral shaping Improved detection algorithms Circuits Improved ADCs higher speed, lower power, scalable Future UWB may go to higher bandwidth Converter power will always be critical issue Variable bias point RF low power for benign environments, higher power for interference Optimal/scalable quantization for soft decision Viterbi Antennas/filters WLAN, UMTS supression European 3-5GHz supression to -85dBm/MHz (hope not!)
DAA in a WiMedia TDMA MAC 10 1.5 2 x 104 1 Averaged 0.5 0 0 20 40 60 80 100 120 140 256μS 25 20 15 10 5 Instantaneous WiMedia MAC is TDMA Slots can be reserved for spectrum sampling All network Tx shut off Larger number of slots increases probability of detecting beacon But reduces UWB data throughput Work continues to explore cyclostationary signals WiMax beacons FFT frame number 50 100 150 200 250 300 350 400 0 0 20 40 60 80 100 120 140 20 40 60 80 100 120 FFT bin number
11 Preview of DAA demo upstairs
What about 60GHz? 12 Complements existing UWB Higher speeds than practical with UWB More power allows increased range Excellent support for point and shoot file transfers ipod, digital camera, other mobile devices Will end up as part of the WPAN ecosystem over time Won t replace UWB, IMHO Some usage models (WPAN) aren t well suited to 60GHz physics Dual radios will happen - someday
Wrapup 13 Commercial deployment of UWB (MB-OFDM) is happening Multiple interoperable sources of silicon rushing to market ISO standards USB-IF and Bluetooth support Regulatory will remain interesting Plenty of interesting research remains! Look for UWB products on the shelves this fall!