July 2003 doc.: IEEE 802.15-03/153r7 Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs) etworks (WPANs) Project: IEEE P802.15 Working Group for Wireless Personal Area N Submission Title: [XtremeSpectrum CFP Presentation] Date Submitted: [July 2003] Source: [Matt Welborn] Company [XtremeSpectrum, Inc.] Address [8133 Leesburg Pike, Suite 700, Vienna, Va. 22182, USA] Voice:[+1 703.269.3000], FAX: [+1 703.749.0248], E-Mail:[mwelborn@xtremespectrum.com] Re: [Response to Call for Proposals, document 02/372r8] Abstract: [] Purpose: [Summary Presentation of the XtremeSpectrum proposal. Details are presented in document 03/154 along with proposed draft text for the 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 Welborn, XtremeSpectrum, Inc.
July 2003 doc.: IEEE 802.15-03/153r7 Compliant Frequency Hoppers suffer degraded performance under current FCC UWB Rules 1 • FCC has expressed deep reservations about FH systems at every stage of UWB proceeding. • To date,no interference studies have been done using FH modulations. • FCC’s Part 15 rules on FH UWB are clear on their face: – A UWB frequency hopper must be tested for compliance with the hopping turned off and the signal "parked" or held stationary at one band of frequencies. (First R&O at para. 32.) – The bandwidth must be at least 500 MHz with the hopping turned off. – The device must comply with the emissions limits with the hopping turned off. Result: The performance of compliant FH systems is seriously degraded because a hopper is NOT allowed to put as much energy as a non-hopper (both covering the same total range of frequencies). – The maximum permitted power is reduced in proportion to the number of hops – N=number of hops Range is reduced by 1/ √ N assuming 1/R 2 propagation – – Data-rate is reduced by 1/N assuming all else is equal. – Example - 10 m range is reduced to 5.8 m range using three hops Note 1: Reference doc IEEE802.15-03/271 Submission Slide 2 Welborn, XtremeSpectrum, Inc.
July 2003 doc.: IEEE 802.15-03/153r7 Illustration of how to test a compliant UWB FH radio With Hopping turned OFF: 1. Bandwidth here must meet FCC UWB definition of > 500 MHz bandwidth; AND 2. W/MHz emissions must be within all emission limits defined in the rules • Pulses/Symbols always come out at same rate • The total average power is the same Pulse Forming Network with or without hopping stopped or OFDM Symbol Maker • With hopping stopped all power is concentrated in one band instead of N bands • Switch is synchronized to the PFN/symbol maker • Switch rotates to hop the >500 MHz bandwidth pulse (or symbol) to a different center frequency • Switch stops rotating to stop hopping F Z F A F B …… Multi-Tone Generator A compliant FH system has only 1/N th the power of a non-hopping system so that it meets the emission limits with hopping turned off Submission Slide 3 Welborn, XtremeSpectrum, Inc.
Timing versus Power and Frequency Diagrams for frequency hoppers July 2003 doc.: IEEE 802.15-03/153r7 Hopping on (normal operation) Hopping off (for compliance testing) Hopping Stopped Hopping On Power – All Symbols/Pulses in same band – Symbols cycle across bands over time Power …… …… Band Band Band Band Band Band Band Band Band Band Band …… A B Z A B B B B B B B Time Time Average Power (dBm/MHz) Average power (dBm/MHz) Pulse Burst is in Band-B with Hopping OFF in Band-B with Hopping ON within FCC Must meet emission limit Must be 1/N times emission limit emission limit Frequency Frequency Hopping Stopped Band F Z F Z ……… Z – All Symbols/Pulses in same band Hopping ON – Energy from other bands are – Symbols in different bands concentrated into one band Burst Quiet Band Band Band Band Band Band Band Band F B F B B B B B B B B B Band Band F A F A A A Time Time Turning hopping off concentrates the energy so a compliant FH system has only 1/N th the power of a non-hopping system Submission Slide 4 Welborn, XtremeSpectrum, Inc.
Power versus Frequency Diagrams For Frequency Hoppers July 2003 doc.: IEEE 802.15-03/153r7 Class B Emission Limit Class B Emission Limit Band Power Power DS-CDMA DS-CDMA Z pwr Power vs Power vs Hopper …… Frequency Frequency Power vs Frequency 1/N Class B Band Hopper A pwr Emission Limit Power vs Band Frequency Band Band Band …… …… B pwr A B Z Frequency Frequency F A F B F Z F A F B F Z Hopping OFF Hopping On – Power Adds N-times into Same band - each band limited to 1/N of emission limit – Total must be below FCC emission limit FH systems have only 1/N th the power of a non-hopping systems The performance of FH systems is seriously degraded. N=number of hops Range is reduced by 1/ √ N assuming 1/R 2 propagation Data-rate is reduced by 1/N assuming all else is equal. Example - 10 m range is reduced to 5.8 m range using three hop system Submission Slide 5 Welborn, XtremeSpectrum, Inc.
Two Band DS-CDMA July 2003 doc.: IEEE 802.15-03/153r7 Low Band High Band 3 4 5 6 7 8 9 10 11 3 4 5 6 7 8 9 10 11 � Low Band (3.1 to 5.15 GHz) � High Band (5.825 to 10.6 GHz) � 28.5 Mbps to 400 Mbps � 57 Mbps to 800 Mbps � Supports low rate, longer range services � Supports high rate, short range services Multi-Band 3 Spectral Modes of With an appropriate diplexer, the multi-band mode will support full-duplex operation (RX in Operation one band while TX in the other) 3 4 5 6 7 8 9 10 11 � Multi-Band (3.1 to 5.15 GHz plus 5.825 GHz to 10.6 GHz) � Up to 1.2 Gbps � Supports low rate, longer range, high rate, short range services Submission Slide 6 Welborn, XtremeSpectrum, Inc.
Spectral Flexibility and Scalability July 2003 doc.: IEEE 802.15-03/153r7 • PHY Proposal accommodates alternate spectral allocations • Center frequency and bandwidth are adjustable • Supports future spectral allocations • Maintains UWB advantages (i.e. wide bandwidth for multipath resolution) Example 2: Support for hypothetical • No changes to silicon “above 6 GHz” UWB definition Example 1: Modified Low Band to include protection for 4.9-5.0 GHz WLAN Band 3 4 5 6 7 8 9 10 11 Note 1: Reference doc IEEE802.15-03/211 3 4 5 6 3 4 5 6 Submission Slide 7 Welborn, XtremeSpectrum, Inc.
Multiple Access: A Critical Choice July 2003 doc.: IEEE 802.15-03/153r7 Multi-piconet capability via: • FDM (Frequency) • Choice of one of two operating frequency bands • Alleviates severe near-far problem • CDM (Code) • 4 CDMA code sets available within each frequency band • Provides a selection of logical channels • TDM (Time) • Within each piconet the 802.15.3 TDMA protocol is used Legend: Low Band (FDM) LB Channel X (CDM) Ch. X 802.15.3a piconet (TDM/TDMA) High Band (FDM) HB Channel X (CDM) Ch. X 802.15.3a piconet (TDM/TDMA) An environment depicting multiple collocated piconets Submission Slide 8 Welborn, XtremeSpectrum, Inc.
Overview July 2003 doc.: IEEE 802.15-03/153r7 Why a Multi-Band CDMA PSK Approach? • Support simultaneous full-rate piconets • Low cost, low power • Uses existing 802.15.3 MAC – No PHY layer protocol required • Time to market – Silicon in 2003 Submission Slide 9 Welborn, XtremeSpectrum, Inc.
Proven Technology July 2003 doc.: IEEE 802.15-03/153r7 This PHY proposal is based upon proven and common communication techniques Transmitter High Band RF Scrambler FEC Preamble Symbol Code Set Pulse Data Encoder Prepend Mapper Modulation Shaper Low Band RF . Multi-Band RF • Multiple bits/symbol via MBOK coding • Data rates from 28.5 Mbps to 1.2 Gbps • Multiple access via ternary CDMA coding • Support for CCA by exploiting higher order properties of BPSK/QPSK • Operation with up to 8 simultaneous piconets Submission Slide 10 Welborn, XtremeSpectrum, Inc.
Scrambler and FEC Coding July 2003 doc.: IEEE 802.15-03/153r7 � Scrambler (15.3 scrambler) � Seed passed as part of PHY header g(D)=1+D 14 +D 15 D D D D � Forward error correction options � Convolutional FEC code (<200 Mbps – 2002 technology ) � ½ rate K=7, (171, 133) with 2/3 and 3/4 rate puncturing � Convolutional interleaver � Reed-Solomon FEC code (high rates) � RS(255, 223) with byte convolutional interleaver � Concatenated FEC code (<200 Mbps – 2002 technology ) Submission Slide 11 Welborn, XtremeSpectrum, Inc.
Pulse Shaping and Modulation July 2003 doc.: IEEE 802.15-03/153r7 � Approach uses tested direct-sequence spread spectrum techniques � Pulse filtering/shaping used with BPSK/QPSK modulation � 50% excess bandwidth, root-raised-cosine impulse response � Harmonically related chipping rate, center frequency and symbol rate � Reference frequency is 684 MHz RRC BW Chip Rate Code Length Symbol Rate Low 1.368 GHz 1.368 GHz 24 57 MS/s chips/symbol ( ± 1 MHz, ± 3 MHz) Band High 2.736 GHz 2.736 GHz 24 114 MS/s chips/symbol ( ± 1 MHz, ± 3 MHz) Band Submission Slide 12 Welborn, XtremeSpectrum, Inc.
Recommend
More recommend
