March 2003 doc.: IEEE 802.15-03/143 Project: IEEE P802.15 Working Group for Wireless Personal Area Networks ( etworks (WPANs WPANs) ) Project: IEEE P802.15 Working Group for Wireless Personal Area N Submission Title: [Time Domain’s Proposal for UWB Multi-band Alternate Physical Layer for 802.15.3a] Date Submitted: [3 March, 2003] Source: [Joy Kelly] Company [Time Domain Corporation] Address [7057 Old Madison Pike, Huntsville, AL 35802 US] Voice:[256-428-6576], FAX: [256-428-6785], E-Mail:[joy.kelly@timedomain.com] Re: [802.15.3a Call for Proposals] Abstract: [This presentation summarizes Time Domain’s UWB Multi-band proposal for the 802.15.3a Alternate PHY standard.] Purpose: [The presentation responds to the Call for Proposals issued by TG 802.15.3a, in consideration for the 802.15.3 Alternate 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. Submission Slide 1 Joy Kelly, Time Domain Corporation
March 2003 doc.: IEEE 802.15-03/143 Time Domain Corporation Proposal for UWB Multi-band Alternate Physical Layer for TG 802.15.3a Submission Slide 2 Joy Kelly, Time Domain Corporation
March 2003 doc.: IEEE 802.15-03/143 Key Selection Criteria Performance Metrics for WPAN Alt PHY • Cost • Power consumption • High data rates • Channelization • Performance in multipath • Interference rejection • Coexistence Submission Slide 3 Joy Kelly, Time Domain Corporation
March 2003 doc.: IEEE 802.15-03/143 Overview of UWB Solution Space f f f f Impulse Impulse Notched Impulse Notched Impulse f f f f Dual Band Dual Band Multi-band Multi-band Submission Slide 4 Joy Kelly, Time Domain Corporation
March 2003 doc.: IEEE 802.15-03/143 Time Domain’s Multi-band Solution • Flexible spectrum use • Time-frequency (TF) codes for multiple access (TFMA) • Simple modulation schemes • Standard Forward Error Correction (FEC) • Graceful scalability with backward compatibility • Strategies for increased multiple access capability in harsh environments Submission Slide 5 Joy Kelly, Time Domain Corporation
March 2003 doc.: IEEE 802.15-03/143 Flexible Spectrum Use Unexpected Interferer Low Frequency Group High Frequency Group Reserved 0 1 2 3 4 5 6 7 9 10 11 12 13 14 15 Sacrifice 1 band for WLAN coexistence (dependent upon geographical location) • ~520 MHz bands to best utilize spectrum • 437 MHz band separation • Adjacent band isolation: ~ 12 dB – Second band over is ~ 21 dB down • Center frequencies chosen for ease of implementation Submission Slide 6 Joy Kelly, Time Domain Corporation
March 2003 doc.: IEEE 802.15-03/143 Signal Design Using 7 Bands • 3.9 ns chip time • Rectified cosine envelope Band 0 Sinewave Carrier Rectified Cosine Pulse Shape 1 0.1 Amplitude (volts) Amplitude (Volts) x 0 0.5 0.1 0 2 1.5 1 0.5 0 0.5 1 1.5 2 2 1 0 1 2 Time (ns) Time (ns) Band 0 Frequency Spectrum Shape 40 Normalized Amplitude (dB) 42.5 Band 0 Chip Waveform 0.2 45 Amplitude (Volts 47.5 0 50 52.5 0.2 2 1 0 1 2 55 3 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 4 Time (ns) Frequency (GHz) Submission Slide 7 Joy Kelly, Time Domain Corporation
March 2003 doc.: IEEE 802.15-03/143 Length 7 Time-Frequency Code 5 6 4 0 0 3 3 1 1 2 2 3.89 ns chip time Code duration 27.23 ns • Time-Frequency Multiple Access (TFMA) radio • One frequency on the air at a time – Enables simplicity in receiver architecture – Provides low power solution Submission Slide 8 Joy Kelly, Time Domain Corporation
March 2003 doc.: IEEE 802.15-03/143 Time-Frequency Code Design 5 Bands 6 Bands 4 Bands 7 Bands 7 Bands Code 0 4 5 6 4 4 5 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 3 3 3 3 3 3 3 3 4 5 6 0 0 1 1 2 2 3 3 3 3 3 3 4 6 4 4 3 5 5 Code 1 0 0 0 0 0 0 0 0 2 2 2 2 2 2 2 2 4 6 1 1 1 1 1 1 1 1 3 3 3 3 5 0 0 2 2 1 1 3 • Length 7 time-frequency codes Code 2 6 6 5 5 5 4 4 4 4 0 0 0 0 0 0 0 0 0 0 3 3 3 3 3 3 3 3 3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1 • Linear congruential design Code 3 4 4 4 5 5 6 0 0 0 0 0 0 0 0 0 4 1 1 1 1 1 1 1 1 1 5 2 2 2 2 2 2 2 2 2 6 3 3 3 3 3 3 3 3 3 0 1 2 3 • 6 codes in family Code 4 5 5 6 4 4 4 0 0 0 0 0 0 0 0 5 3 3 3 3 3 3 3 3 1 1 1 1 1 1 1 1 6 4 2 2 2 2 2 2 2 2 0 0 3 3 1 1 2 2 • At most one collision between Code 5 6 5 4 5 4 4 0 0 0 0 0 0 0 0 6 5 4 3 3 3 3 3 3 3 3 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 0 0 3 3 2 2 1 1 any two length 7 codes chip chip (provides 17 dB code isolation) time time • Length 7 time-frequency codes provide good multipath resistance (approx 27 ns environment ring down) • Yields 6 unique piconets Submission Slide 9 Joy Kelly, Time Domain Corporation
March 2003 doc.: IEEE 802.15-03/143 Data Modulation • Use low order modulation for simplicity and reasonable dynamic range requirements – BPSK – QPSK • Apply modulation on a per-chip basis • Length 7 code (using all frequencies) yields raw data rates – 257 Mb/s for BPSK – 514 Mb/s for QPSK Submission Slide 10 Joy Kelly, Time Domain Corporation
March 2003 doc.: IEEE 802.15-03/143 Forward Error Correction (FEC) • Convolutional encoder – ½ rate – ¾ rate • Constraint length 7 • Industry standard generating polynomials • Spreads each bit across spectrum • Multi-band method with per-band modulation enables weighting of each frequency band in soft decision Submission Slide 11 Joy Kelly, Time Domain Corporation
March 2003 doc.: IEEE 802.15-03/143 Modulation Schemes • 8 modulation combinations defined – Fits within existing 3-bit PHY Header field Modulation Scheme Payload Bit Rate (Mb/s) Index BPSK QPSK FEC Frequency 4 Bands 7 Bands 14 Bands Integration � � None 0* 37 37 37 � ½ Rate 3 73 128 257 � 5 ½ Rate 147 257 514 � None 7 294 514 1028 *Mode 0 is base rate: used for all header /beacon / CAP signaling Submission Slide 12 Joy Kelly, Time Domain Corporation
March 2003 doc.: IEEE 802.15-03/143 Flexibility of Multi-band: Dynamic Band Management • Monitor and report per-band performance • Detect spectral problems, if any • Four categories – Narrowband interferer – Channel fading – Nearby interfering piconet (near/far) – Multiple near-proximity piconets in extreme multipath Submission Slide 13 Joy Kelly, Time Domain Corporation
March 2003 doc.: IEEE 802.15-03/143 Solution for Narrowband Interference & Channel Fading • Coordinate between DEVs within piconet to drop affected bands 0 1 2 3 4 5 6 4 4 0 1 2 3 4 5 6 Example: Band 4 dropped Submission Slide 14 Joy Kelly, Time Domain Corporation
March 2003 doc.: IEEE 802.15-03/143 Solution for Nearby Interfering Piconet & Multiple Piconets in Extreme Multipath • TF codes provide 17dB code isolation between channels in freespace • In extreme situations, Near-Far Conditions additional isolation required • Activate FDMA (frequency division multiple access) strategy • Continue using same TF codes • Return to TFMA when conditions permit CM4 CIR Plot (Example) Submission Slide 15 Joy Kelly, Time Domain Corporation
March 2003 doc.: IEEE 802.15-03/143 Scalability: Very High Data Rates Code Group A Code Group B R e s e r v e d • Codes are re-used in upper frequency group • Enables 14-band DEVs allowing > 1 GHz raw data rate • Requires transmission and reception of two bands simultaneously Submission Slide 16 Joy Kelly, Time Domain Corporation
March 2003 doc.: IEEE 802.15-03/143 Scalability & Flexibility: Within a Piconet 0 1 2 3 4 5 6 0’ 1’ 2’ 3’ 4’ 5’ 6’ DEV 1 DEV 2 0 1 2 3 4 5 6 DEV 3 0 1 2 3 4 5 6 • Signaling design enables DEVs of different capability within a piconet to communicate • Band assessment, negotiation easily enabled via minimal MAC supplements • Enables products of varying capabilities to be tailored for different applications Submission Slide 17 Joy Kelly, Time Domain Corporation
March 2003 doc.: IEEE 802.15-03/143 Scalability: Uncoordinated Piconets • Code collision property holds for 14 bands • 1 collision in 7; 2 in 14 • Each piconet is independently configured • Reconfiguring a given piconet does not adversely affect the other piconets 0 1 2 3 4 5 6 0’ 1’ 2’ 3’ 4’ 5’ 6’ Piconet 1 0 3 6 2 5 1 4 0’ 3’ 6’ 2’ 5’ 1’ 4’ Example: 0 6 5 4 3 2 1 0’ 6’ 5’ 4’ 3’ 2’ 1’ Piconet 6 code group A code group B code group A code group B Submission Slide 18 Joy Kelly, Time Domain Corporation
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