Transcript WCNC2003_UWB_McCorkle.ppt

XtremeSpectrum
Inc.
IEEE Wireless
Communications
and Networking
Conference
(WCNC‘2003)
Enabling Wireless
Multimedia
John McCorkle
CTO
[email protected]
Ultra-Wideband:
A New Wireless Technology
 A military technology transitioning to the commercial
market
 Simultaneous delivery of
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High Data Rate
Low Power – Long Battery Life
Low Cost
 FCC approved on February 14, 2002:
3.1-10.6 GHz
IEEE Wireless Communications and Networking Conference (WCNC'2003), 19Mar03
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UWB - A Unique Opportunity
 A fundamental change in this allocation of spectrum
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Wide low-power versus  narrow high-power
Requires new thought as to the utilization of this allocation
(don’t be entrapped by legacy narrowband approaches)
 A technology who’s fundamental benefits come from the unique
nature of wide bandwidth transmissions within multipath
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Capturing these benefits requires a move away from legacy incoherent
frequency division and toward wide fully coherent processing.
 A market opportunity that changes the fundamental tradeoffs of
performance vs. cost/power consumption
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Bluetooth price, but speed and QoS beyond 802.11a,g
An intersection of PC and CE products (inc. mobile telephony)
IEEE Wireless Communications and Networking Conference (WCNC'2003), 19Mar03
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Fundamental Issues
 Multi-user performance
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Consumer usage means pervasive horizontal deployment
 Simultaneous full rate support
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Each user will want to take full advantage of the maximum rate supported
with high QOS in multipath
 Spectral Flexibility and Scalability
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For new regulatory environments on a worldwide basis
Modifications to existing rules
 Narrowband Interference avoidance/mitigation
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For existing systems (UNII band) and new narrowband allocations
IEEE Wireless Communications and Networking Conference (WCNC'2003), 19Mar03
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Full Rate Support
For Multiple Overlapping Piconets
 High aggregate rates in multipath
 Modulation choice for low SNR
- Efficiency is key in two domains
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Constellation with greatest distance between points – Lowest SNR
Scalability - High ratio of incremental performance versus hardware
complexity/power
BPSK & QPSK with M-BOK provide both
 Multiple Access Techniques
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CDMA (Maximize coding on all radiated energy)
FDMA (Effective for extreme situations
back to back TV sharing a wall between two apartments)
TDMA within a piconet (QoS guarantee)
IEEE Wireless Communications and Networking Conference (WCNC'2003), 19Mar03
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Three Spectral Modes of Operation
Low Band
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Low Band (3.1 to 5.15 GHz)
 28.5 Mbps to 400 Mbps
 4 piconets give 1.6 Gbps aggregate
Multi-Band
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High Band
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High Band (5.825 to 10.6 GHz)
 57 Mbps to 800 Mbps
 4 piconets give 3.2 Gbps aggregate
 Multi-Band (3.1 to 5.15 GHz plus 5.825 GHz to 10.6 GHz)
 Up to 1.2 Gbps per piconet – 4.8 Gbps aggregate
 Full Duplex Mode
 Frequency Division Multiplexing (FDM) Mode
Wide gap gives >60 dB isolation
Allows nodes in neighboring piconets to be inches
apart
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Wide 50% coherent bandwidth in each band derives benefits of UWB in high multipath
 Small multipath dips, small link margin requirements
 Many paths resolved, very robust --multiple paths exist that can make the link work
 Processing gain versus narrowband interference
IEEE Wireless Communications and Networking Conference (WCNC'2003), 19Mar03
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Spectral Flexibility & Scalability
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New bands easy to add
Clear Channel Assessment Capability Allows All MAC modes and simple scaleable management
Processing gain against narrowband interference – 6dB lo-band, 9dB hi-band rel. to 500MHz BW bands
Bandwidth programmable with
current-controlled cut-off frequency
Low Pass filter
Center frequency
programmable with PLL
Example 1: Modified Low Band to include
protection for 4.9-5.0 GHz WLAN Band
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Example 2: Support for hypothetical
“above 6 GHz only” UWB definition
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Air Interface Is A Simple
Joint Time Frequency Wavelet Family
 Easy-to-make short-time (1-chip period) pulses give 60 dB FDM isolation due to wide gap between bands
 Widest contiguous bands – Getting highest coding gain possible maximizes performance in many dimensions
• FDM, Processing gain against RFI, Coding gain for overlapping piconets in multipath, simpler silicon
• Highest performance for lowest bill of materials cost
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