Mar 2005 doc IEEE 802 15 05 0130

Mar. 2005 doc. : IEEE 802. 15 -05 -0130 -01 -004 a Project: IEEE P 802. 15 Working Group for Wireless Personal Area Networks (WPANs) Submission Title: STM_CEA-LETI_CWC_AETHERWIRE_MITSUBISHI_FTR&D 15. 4 a. CFP response Date Submitted: January 4 th, 2005 Source: Ian Oppermann (1), Mark Jamtgaard (2), Laurent Ouvry (3), Philippe Rouzet (4), Andreas F. Molisch(5), Philip Orlik(5), Zafer Sahinoglu (5), Rick Roberts (6), Vern Brethour (7), Adrian Jennings (7) , Patricia Martigne (8), Benoit Miscopein (8), Jean Schwoerer (8) Companies: (1) CWC-University of Oulu, Tutkijantie 2 E, 90570 Oulu, FINLAND (2) Æther Wire & Location, Inc. , 520 E. Weddell Drive, Suite 5, Sunnyvale, CA 94089, USA (3) CEA-LETI, 17 rue des Martyrs 38054, Grenoble Cedex, FRANCE (4) STMicroelectronics, CH-1228, Geneva, Plan-les-Ouates, SWITZERLAND (5) MERL, 201 Broadway, Boston, USA (6) Harris, (7)Time Domain, Hansville, Alabama (8) FT R&D, 28 Chemin des vieux chênes, BP 98, 38243 Meylan Cedex Voice: (1) +358 407 076 344, (2) 408 400 0785 (3) +33 4 38 78 93 88, (4) +41 22 929 58 66 (5) +1 617 621 7500 E-Mail: (1) ian@ee. oulu. fi, (2) mark@aetherwire. com(3) laurent. ouvry@cea. fr, (4) philippe. rouzet@st. com, (5) {molisch, porlik, zafer}@merl. com, rrober 14@harris. com, {vern. brethour, adrian. jennings}@timedomain. com, (8) {patricia. martigne, benoit. miscopein, jean. schwoerer}@francetelecom. com Abstract: UWB proposal for 802. 15. 4 a alt-PHY Purpose: Proposal based on UWB impulse radio for the IEEE 802. 15. 4 a CFP Notice: This document has been prepared to assist the IEEE P 802. 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 contributors acknowledge and accept that this contribution becomes the property of IEEE and may be CWC/AETHERWIRE/CEA-LETI/STM/MERL Slide 1 made publicly available by P 802. 15

Mar. 2005 doc. : IEEE 802. 15 -05 -0130 -01 -004 a List of Authors • CWC – Ian Oppermann, Alberto Rabbachin (1) • Aether. Wire – Mark Jamtgaard, Patrick Houghton (2) • CEA-LETI – Laurent Ouvry, Samuel Dubouloz, Sébastien de Rivaz, Benoit Denis, Michael Pelissier, Manuel Pezzin et al. (3) • STMicroelectronics – Gian Mario Maggio, Chiara Cattaneo, Philippe Rouzet & al. (4) • MERL – Andreas F. Molisch, Philip Orlik, Zafer Sahinoglu (5) • Harris – Rick Roberts (6) • Time Domain – Vern Brethour, Adrian Jennings (7) • France Telecom R&D – Patricia Martigne, Benoit Miscopein, Jean Schwoerer (8) Slide 2 CWC/AETHERWIRE/CEA-LETI/STM/MERL

Mar. 2005 doc. : IEEE 802. 15 -05 -0130 -01 -004 a Outline • • • • Introduction Background Transmitted Signal Receiver Architectures Bandwidth Usage Optional Aspects System performances Link budget Framing, throughput Power Saving Ranging and Delay Estimation Feasibility Conclusions Slide 3 CWC/AETHERWIRE/CEA-LETI/STM/MERL

Mar. 2005 doc. : IEEE 802. 15 -05 -0130 -01 -004 a Proposal Main Features 1. Impulse-radio based (pulse-shape independent) 2. Support for different receiver architectures (coherent/noncoherent) 3. Flexible modulation format 4. Support for multiple rates 5. Enables accurate ranging/positioning 6. Support for multiple SOP Slide 4 CWC/AETHERWIRE/CEA-LETI/STM/MERL

Mar. 2005 doc. : IEEE 802. 15 -05 -0130 -01 -004 a Motivation for (2 -4): • Supports homogenous and heterogeneous network architectures • Different classes of nodes, with different reliability requirements (and cost) must inter-work Slide 5 CWC/AETHERWIRE/CEA-LETI/STM/MERL

Mar. 2005 doc. : IEEE 802. 15 -05 -0130 -01 -004 a UWB Technology • Impulse-Radio (IR) based: – Very short pulses Reduced ISI – Robustness against fading – Episodic transmission (for LDR) allowing long sleep-mode periods and energy saving • Low-complexity implementation Slide 6 CWC/AETHERWIRE/CEA-LETI/STM/MERL

Mar. 2005 doc. : IEEE 802. 15 -05 -0130 -01 -004 a Modulation Features • Simple, scalable modulation format • Flexibility for system designer • Modulation compatible with multiple coherent/non-coherent receiver schemes • Time hopping (TH) to achieve multiple access Slide 7 CWC/AETHERWIRE/CEA-LETI/STM/MERL

Mar. 2005 doc. : IEEE 802. 15 -05 -0130 -01 -004 a Commonalities with Other Proposals • The present document is the result of preliminary merging efforts among the new CWC/STm/LETI/Aether. Wire/MERL/Harris/FTR&D/TDC group. Work is still ongoing for refining and consolidation of some of the parameters described in this proposal. • Discussions are under way for further collaborations and merging in 802. 15. 4 a. Slide 8 CWC/AETHERWIRE/CEA-LETI/STM/MERL

Mar. 2005 doc. : IEEE 802. 15 -05 -0130 -01 -004 a Outline • • • • Introduction Background Transmitted Signal Receiver Architectures Bandwidth Usage Optional Aspects System performances Link budget Framing, throughput Power Saving Ranging and Delay Estimation Feasibility Conclusions Slide 9 CWC/AETHERWIRE/CEA-LETI/STM/MERL

Mar. 2005 doc. : IEEE 802. 15 -05 -0130 -01 -004 a Definitions Coherent RX: The phase of the received carrier waveform is known, and utilized for demodulation Differentially-coherent RX: The carrier phase of the previous signaling interval is used as phase reference for demodulation Non-coherent RX: The phase information (e. g. pulse polarity) is unknown at the receiver -operates as an energy collector -or as an amplitude detector Slide 10 CWC/AETHERWIRE/CEA-LETI/STM/MERL

Mar. 2005 doc. : IEEE 802. 15 -05 -0130 -01 -004 a Pros (+) and cons (-) of RX architectures: Coherent • • • + : Sensitivity + : Use of polarity to carry data + : Optimal processing gain achievable - : Complexity of channel estimation and RAKE receiver - : Longer acquisition time Differential (or using Transmitted Reference) • + : Gives a reference for faster channel estimation (coherent approach) • + : No channel estimation (non-coherent approach) • - : Asymptotic loss of 3 d. B for transmitted reference (not for DPSK) Non-coherent • + : Low complexity • + : Acquisition speed • - : Sensitivity, robustness to SOP and interferers Slide 11 CWC/AETHERWIRE/CEA-LETI/STM/MERL

Mar. 2005 doc. : IEEE 802. 15 -05 -0130 -01 -004 a Time Hopping Impulse Radio (TH-IR) - Principle +1 Tc Tf Ts -1 • Each symbol represented by sequence of very short pulses (see also Win & Scholtz 2000) • Each user uses different sequence (Multiple access capability) • Bandwidth mostly determined by pulse shape Slide 12 CWC/AETHERWIRE/CEA-LETI/STM/MERL

Mar. 2005 doc. : IEEE 802. 15 -05 -0130 -01 -004 a Transmitted Reference (TR) • TR schemes simplify the channel estimation process • Reference waveform available for synchronisation • Potentially more robust (than non-coherent) under SOP operation • Supports both coherent/differentially-coherent demodulation • Implementation challenges: – Analogue: Implementing delay value, – delay mismatch, jitter Slide 13 CWC/AETHERWIRE/CEA-LETI/STM/MERL

Mar. 2005 doc. : IEEE 802. 15 -05 -0130 -01 -004 a Transmitted Reference data Td +1 Tc Tf reference Ts -1 • First pulse serves as template for estimating channel distortions • Second pulse carries information • Drawback: Waste of 3 d. B energy on reference pulses Slide 14 CWC/AETHERWIRE/CEA-LETI/STM/MERL

Mar. 2005 doc. : IEEE 802. 15 -05 -0130 -01 -004 a Outline • • • • Introduction Background Transmitted Signal Receiver Architectures Bandwidth Usage Optional Aspects System performances Link budget Framing, throughput Power Saving Ranging and Delay Estimation Feasibility Conclusions Slide 15 CWC/AETHERWIRE/CEA-LETI/STM/MERL

Mar. 2005 doc. : IEEE 802. 15 -05 -0130 -01 -004 a Design Parameters (1) • Motivation: – Flexible waveform – Simple – Compatible with multiple coherent/non-coherent receiver schemes • Large Bandwidth • • • (+) Higher transmit power (+) improved time resolution (-) Increased design complexity (-) Less stringent requirements on out of band interference filtering Signal BW of 500 MHz - 2 GHz in Upper bands Signal BW of 700 MHz in 0 to 960 MHz Lower band (low band) Long Pulse Repetition Period • (+) more energy per pulse (easier to detect single pulse) • (+) Lower inter-pulse interference due to channel delay spread • (-) Higher peak voltage requirements at transmitter • (-) Longer acquisition time Frame duration between 40 ns (first realization) and 125 ns (second realizations). Higher values for the frame duration have been mentioned. Further discussions are required to fix the values Slide 16 CWC/AETHERWIRE/CEA-LETI/STM/MERL

Mar. 2005 doc. : IEEE 802. 15 -05 -0130 -01 -004 a Design Parameters (2) • Simple modulation schemes: • BPPM combined with Transmitted Reference • Channelization : • Coherent schemes: Use of TH codes and polarity codes • Non-coherent schemes: Use of TH codes (polarity codes for spectrum smoothing only) • Long TH code length • (+) higher processing gain, robustness to SOP operation • (-) Lower bit-rate • (-) Longer acquisition time, shorter frame size (synch. phase) Þ TH code length 8 or 16 TH code : binary position (delay of 0 or τΔ ), bi-phase For first realization, higher-order TH with shorter chip duration (multiples of 2 ns) can be used. This is under discussion Slide 17 CWC/AETHERWIRE/CEA-LETI/STM/MERL

Mar. 2005 doc. : IEEE 802. 15 -05 -0130 -01 -004 a Transmission • Basic idea: use modulation scheme that allows coherent, differentially coherent, and incoherent reception • Combine BPPM with more sophisticated TR scheme – Non-coherent receiver sees BPPM with pulse stream per bit – More sophisticated receiver sees BPPM (1 bit) plus bits carried in more sophisticated modulation scheme (e. g. extended TR) • Advantages: – Coherent, differential and non-coherent receiver may coexist – reference can be used for synch and threshold estimation • Concept can be generalized to N-ary TR system Slide 18 CWC/AETHERWIRE/CEA-LETI/STM/MERL

Mar. 2005 doc. : IEEE 802. 15 -05 -0130 -01 -004 a Waveform Design • Coexistence of coherent and non-coherent architectures • Combine BPPM with BPSK • Divide each symbol into two 125 ns BPPM slots (250 ns symbol) • In either slot transmit a signal that can be received with a variety of receivers: differentially coherent or coherent receivers. • Non-coherent receivers just look for energy in the early or late slots to decode the bit. • Other receivers understand the fine structure of the signal. Slide 19 CWC/AETHERWIRE/CEA-LETI/STM/MERL

Mar. 2005 doc. : IEEE 802. 15 -05 -0130 -01 -004 a Waveform Design • Two possible realizations: – The whole symbol (consisting of N_f frames) is BPPM-modulated. – Have a 2 -ary time hopping code, so that each frame has BPPM according to TH code Slide 20 CWC/AETHERWIRE/CEA-LETI/STM/MERL

Mar. 2005 doc. : IEEE 802. 15 -05 -0130 -01 -004 a First Realization Slide 21 CWC/AETHERWIRE/CEA-LETI/STM/MERL

Mar. 2005 doc. : IEEE 802. 15 -05 -0130 -01 -004 a Second Realization Ts « 11 » 2 -PPM + TR base M=2 (with two bits/symbol) One bit/symbol also Possible !!! « 01 » « 10 » « 00 » (coherent decoding possible) 2 -PPM + 16 chips 2 -ary TH code This is a time-hopping that can be exploited by non-coherent receiver Time hopping code is (2, 2) code of length 8 or 16 Effectively 28 or 216 codes to select for channelization for non-coherent scheme Slide 22 CWC/AETHERWIRE/CEA-LETI/STM/MERL

Mitigation of peak voltage through multi pulses Mar. 2005 doc. : IEEE 802. 15 -05 -0130 -01 -004 a Tf=PPI pp. V = peak-to-peak voltage M=1 IS « EQUIVALENT » TO Tf=PPI M=4 pp. V/2 Tf=PPI M=2 pp. V/sqrt(2) Slide 23 CWC/AETHERWIRE/CEA-LETI/STM/MERL

Mar. 2005 doc. : IEEE 802. 15 -05 -0130 -01 -004 a Coexistence of Different Receiver Architectures • Want waveform that allows TR reception without penalizing coherent reception • That is achieved by special encoding and waveform shaping within each frame. Does not affect the co-existence of coherent/noncoherent receivers Slide 24 CWC/AETHERWIRE/CEA-LETI/STM/MERL

Mar. 2005 doc. : IEEE 802. 15 -05 -0130 -01 -004 a Basic Properties • Use of Doublets with memory from previous bit. (Encoding of reference pulse with previous bit) – Agreed on 20 ns separation between pulses – Extensible to higher order TR for either reducing the penalty in transmitting the reference pulse or increasing the bit rate? – Also allows the use of multi-DOUBLET Slide 25 CWC/AETHERWIRE/CEA-LETI/STM/MERL

Mar. 2005 doc. : IEEE 802. 15 -05 -0130 -01 -004 a Differential Encoding of Bits b-1 0 b 1 b 2 b 3 b 4 b 5 0 1 1 0 0 1 -1 -1 +1 +1 -1 -1 +1 -1 Tx Bits Reference Polarity Ts Note: This slide is meant to describe the encoding of data on the reference pulse and data pulse in the basic modulation format. For simplicity we have omitted the multipulse/multiframes per symbol structure. Slide 26 CWC/AETHERWIRE/CEA-LETI/STM/MERL

Mar. 2005 doc. : IEEE 802. 15 -05 -0130 -01 -004 a Total Modulation Scheme (First Realization) THE KEY SLIDE OF THE PROPOSAL: this is the modulation format that allows Coherent, differentially coherent, and non-coherent demodulation at once Slide 27 CWC/AETHERWIRE/CEA-LETI/STM/MERL

Mar. 2005 doc. : IEEE 802. 15 -05 -0130 -01 -004 a Higher-order modulation D D D « 1» « 11» τdelay +τΔ Basic Mode (as seen by non-coherent) D D D τdelay +τΔ Enhanced Mode 1 « 10» Pulse Shift, polarity invert τΔ + τdelay TH Code Data 1, 1 τΔ + τdelay 1, 1 τΔ τdelay 0, 1 1, 1 τΔ τdelay 0, 0 1, 1 Slide 28 τΔ + τdelay 1, 0 1, 1 τΔ + τdelay 0, 1 0, 0 TH Pattern CWC/AETHERWIRE/CEA-LETI/STM/MERL

Mar. 2005 doc. : IEEE 802. 15 -05 -0130 -01 -004 a Comments on Transmitted Signal • Frame period for solution 2 is Tframe = (Np * D) + τΔ + τdelay – Τdelay is some allowance for channel delay spread • Frame period could be dynamic modified dependant on – the estimated channel delay spread or – ability of receiver to cope with delay spread • Symbol period is length of the TH code x Tframe – Upper Band Nominally 250 ns x 16 = 4 µs – Lower Band Nominally 500 ns x 8 = 4 µs • Realistic Receiver structures exist for multi-pulse TR schemes (see back-up slides) Slide 29 CWC/AETHERWIRE/CEA-LETI/STM/MERL

Mar. 2005 doc. : IEEE 802. 15 -05 -0130 -01 -004 a Outline • • • • Introduction Background Transmitted Signal Receiver Architectures Bandwidth Usage Optional Aspects System performances Link budget Framing, throughput Power Saving Ranging and Delay Estimation Feasibility Conclusions Slide 30 CWC/AETHERWIRE/CEA-LETI/STM/MERL

Mar. 2005 doc. : IEEE 802. 15 -05 -0130 -01 -004 a Proposed RAKE -- Coherent Receiver Channel Estimation Rake Receiver Finger 1 Demultiplexer Rake Receiver Finger 2 Summer Sequence Detector Convolutional Decoder Data Sink Rake Receiver Finger Np • Addition of Sequence Detector – Proposed modulation may be viewed as having memory of length 2 • Main component of Rake finger: pulse generator • A/D converter: 3 -bit, operating at symbol rate • No adjustable delay elements required Slide 31 CWC/AETHERWIRE/CEA-LETI/STM/MERL

Mar. 2005 doc. : IEEE 802. 15 -05 -0130 -01 -004 a Proposed Transmitted Reference Receiver – Differentially Coherent • Addition of Matched Filter prior to delay and correlate operations improves output signal to noise ratio and reduces noise-noise cross terms Matched Filter Convolutional Decoder Td SNR of decision statistic Slide 32 CWC/AETHERWIRE/CEA-LETI/STM/MERL

Mar. 2005 doc. : IEEE 802. 15 -05 -0130 -01 -004 a Differentially-Coherent/Non-Coherent Receiver Architecture Basic Mode and Enhanced Mode 1 Controlled Integrator Band Matched r(t) x 2 RAZ LNA BPF BPPM Demodulation branch Dump Latch RAZ DUMP ADC Tracking Threshol ds setting Ranging branch ADC Dump Latch TR Demodulation branch Delay Controlled Integrator TR BPPM Synch Trigger Energy Analyzer Block index for acquisition reference Leading-edge refinement search Range info Recyle this branch for Enhanced Data Rate Modes Slide 33 CWC/AETHERWIRE/CEA-LETI/STM/MERL

Mar. 2005 doc. : IEEE 802. 15 -05 -0130 -01 -004 a De-spreading TH Codes Band Matched LNA BPF r(t) TH Sequence Matched Filter Bit Demodulation ADC Case I - Coherent TH despreading Band Matched LNA BPF r(t) Bit Demodulation b(t) soft info TH Sequence Matched Filter ADC Case II – Non-coherent / differential TH despreading Slide 34 CWC/AETHERWIRE/CEA-LETI/STM/MERL

Mar. 2005 doc. : IEEE 802. 15 -05 -0130 -01 -004 a Outline • • • • Introduction Background Transmitted Signal Receiver Architectures Bandwidth Usage Optional Aspects System performances Link budget Framing, throughput Power Saving Ranging and Delay Estimation Feasibility Conclusions Slide 35 CWC/AETHERWIRE/CEA-LETI/STM/MERL

Mar. 2005 doc. : IEEE 802. 15 -05 -0130 -01 -004 a Bandwidth Usage (1/4) • Flexible use of (multi-)bands • Signal bandwidth may be 500 MHz to 2 GHz • Bandwidth may change depending on application and regulatory environment • Optional sub-GHz band 140 MHz to 800 MHz with a center frequency of 470 MHz • Use of TH and/or polarity randomization for spectral smoothing • Different bandwidth use options being considered Slide 36 CWC/AETHERWIRE/CEA-LETI/STM/MERL

Mar. 2005 doc. : IEEE 802. 15 -05 -0130 -01 -004 a Bandwidth Usage – 2 GHz option (2/4) ISM Band Upper Band 1 Lower band 0. 96 ISM Band 3. 1 Upper Band 3 Upper Band 2 5. 1 6. 0 Slide 37 8. 0 8. 1 10. 1 GHz CWC/AETHERWIRE/CEA-LETI/STM/MERL

Mar. 2005 doc. : IEEE 802. 15 -05 -0130 -01 -004 a Bandwidth Usage -500 MHz Option (3/4) ISM Band Upper Bands 5 - 12 Upper Bands 1 -4 Lower band 0. 96 3. 1 5. 1 6. 0 8. 1 Slide 38 10. 1 GHz CWC/AETHERWIRE/CEA-LETI/STM/MERL

Mar. 2005 doc. : IEEE 802. 15 -05 -0130 -01 -004 a Bandwidth Usage –Variable Option (4/4) ISM Band Upper Bands 5 - 12 Upper Bands 1 -4 Lower band 0. 96 3. 1 5. 1 6. 0 8. 1 Slide 39 10. 1 GHz CWC/AETHERWIRE/CEA-LETI/STM/MERL

Mar. 2005 doc. : IEEE 802. 15 -05 -0130 -01 -004 a Outline • • • • Introduction Background Transmitted Signal Receiver Architectures Bandwidth Usage Optional Aspects System performances Link budget Framing, throughput Power Saving Ranging and Delay Estimation Feasibility Conclusions Slide 40 CWC/AETHERWIRE/CEA-LETI/STM/MERL

Mar. 2005 doc. : IEEE 802. 15 -05 -0130 -01 -004 a Spectral Shaping & Interference Suppression (Optional) • Basis pulse: use simple pulse shape gaussian, raised cosine, chaotic, etc. Monocycle, 5 th derivative of gaussian pulse 10 log 10|P(f)|2 d. B Power spectral density of the monocycle • Drawbacks: – Possible loss of power compared to FCCfrequency (Hz) allowed power – Strong radiation at 2. 45 and 5. 2 GHz Slide 41 CWC/AETHERWIRE/CEA-LETI/STM/MERL

Mar. 2005 doc. : IEEE 802. 15 -05 -0130 -01 -004 a Linear Pulse Combination • Solution: linear combination of delayed, weighted pulses – Adaptive determination of weight and delay – Number of pulses and delay range restricted – Can adjust to interferers at different distances (required nulldepth) and frequencies • Weight/delay adaptation in two-step procedure • Initialization as solution to quadratic optimization problem (closed-form) • Refinement by back-propagating neural network • Matched filter at receiver good spectrum helps coexistence and interference suppression Slide 42 CWC/AETHERWIRE/CEA-LETI/STM/MERL

Mar. 2005 doc. : IEEE 802. 15 -05 -0130 -01 -004 a Spectral Shaping & Polarity Scrambling Td = 10 ns Td = 20 ns W/O Polarity Scrambling Slide 43 W/ Polarity Scrambling CWC/AETHERWIRE/CEA-LETI/STM/MERL

Mar. 2005 doc. : IEEE 802. 15 -05 -0130 -01 -004 a Adaptive Frame Duration • Advantage of large number of pulses per symbol: – Smaller peak-to-average ratio – Increased possible number of SOPs • Disadvantage: – Increased inter-frame interference – In TR: also increased interference from reference pulse to data pulse • Solution: adaptive frame duration – Feed back delay spread and interference to transmitter – Depending on those parameters, TX chooses frame duration Slide 44 CWC/AETHERWIRE/CEA-LETI/STM/MERL

Mar. 2005 doc. : IEEE 802. 15 -05 -0130 -01 -004 a Outline • • • • Introduction Background Transmitted Signal Receiver Architectures Bandwidth Usage Optional Aspects System performances Link budget Framing, throughput Power Saving Ranging and Delay Estimation Feasibility Conclusions Slide 45 CWC/AETHERWIRE/CEA-LETI/STM/MERL

Mar. 2005 doc. : IEEE 802. 15 -05 -0130 -01 -004 a PER in 15. 4 a Channel Model Non-Coherent (Energy Collection) BPPM Framing format: Preamble SFD LEN (32 bits) (8 bits) MHR+MSDU (240 bits) CRC (16 bits) • Simulations over 1000 channel responses • BW = 2 GHz – Integration Time = 80 ns • Implementation loss + Noise figure margin : 11 d. B • Max range is determined from: - Required Eb/N 0, - Implementation margin - Path loss characteristics X 1 (CM 8) X 2 (CM 1) X 3 (CM 5) X 4 (CM 9) Case I: 250 kbps – PRP 250 ns with 16 pre-integrations = 4 µs Required Eb/N 0 19. 5 d. B 20 d. B 21. 5 d. B Max Range (I) 10. 78 m 84. 61 m 86. 72 m 58. 67 m Case II: 250 kbps – PRP 500 ns with 8 post-integrations Max Range (II) 7. 33 m 53. 25 m 54. 15 m 34. 72 m Slide 46 CWC/AETHERWIRE/CEA-LETI/STM/MERL

Mar. 2005 doc. : IEEE 802. 15 -05 -0130 -01 -004 a PER/BER in 15. 4 a Channel Model DBPSK (RAKE) DBPSK – PER vs. Eb/N 0 – 15. 4 a Channel Models 0 10 X 1 X 2 X 3 X 4 -1 PER 10 -2 10 Theoretical BER Curves – Integration Time = 50 ns -3 10 10 11 12 13 14 15 16 Eb/N 0 (d. B) Case I: 250 kbps – PRP 250 ns with 16 pre-integration = 4 µs Case II: 250 kbps – PRP 500 ns with 8 post-integrations 17 18 19 20 Implementation loss and Noise figure margin : 11 d. B X 1 (CM 8) X 2 (CM 1) X 3 (CM 5) X 4 (CM 9) Required Eb/N 0 18 d. B 17. 5 d. B 18. 5 d. B Max Range (I) 12. 66 m 116. 70 m 120. 27 m 90. 84 m Max Range (II) 9. 18 m 79. 34 m 81. 23 m 58. 67 m Slide 47 CWC/AETHERWIRE/CEA-LETI/STM/MERL

Mar. 2005 doc. : IEEE 802. 15 -05 -0130 -01 -004 a Outline • • • • Introduction Background Transmitted Signal Receiver Architectures Bandwidth Usage Optional Aspects System performances Link budget Framing, throughput Power Saving Ranging and Delay Estimation Feasibility Conclusions Slide 48 CWC/AETHERWIRE/CEA-LETI/STM/MERL

Mar. 2005 doc. : IEEE 802. 15 -05 -0130 -01 -004 a Link Budget: Non-Coherent (Energy Collection) BPPM Mandatory Value (PRP = 4 µs) Optional Value (PRP = 500 ns - 8 integrations) 250 kb/s -10. 64 d. Bm 0 d. Bi 3. 873 GHz 44. 20 d. B 29. 54 d. B @ d = 30 m 0 d. Bi Rx Power (PR = PT + GR – L 1 – L 2) -84. 38 d. Bm Average noise power per bit: N = -174 + 10 log 10(Rb) -120. 02 d. Bm 7 d. B -113. 02 d. Bm Minimum Eb/N 0 (S) 14 d. B 17. 6 d. B Implementation Loss (I) 5 d. B Link Margin (M = PR - PN – S – I) 9. 64 d. B 6. 04 d. B Proposed Min. Rx Sensitivity Level -94. 02 d. Bm -90. 42 d. Bm Parameter Peak Payload bit rate (Rb) Average Tx Power Gain (PT) Tx antenna gain (GT) f’c: (geometric frequency) Path Loss @ 1 m: L 1 = 20 log 10(4. . f’c / c) Path Loss @ d m: L 2 = 20 log 10(d) Rx Antenna Gain (GR) Rx noise figure (NF) Average noise power per bit (PN = N + NF) Slide 49 CWC/AETHERWIRE/CEA-LETI/STM/MERL

Mar. 2005 doc. : IEEE 802. 15 -05 -0130 -01 -004 a Link Budget: DBPSK (RAKE) Mandatory Value (PRP = 4 µs) Optional Value (PRP = 500 ns - 8 integrations) 250 kb/s -10. 64 d. Bm 0 d. Bi 3. 873 GHz 44. 20 d. B 29. 54 d. B @ d = 30 m 0 d. Bi Rx Power (PR = PT + GR – L 1 – L 2) -84. 38 d. Bm Average noise power per bit: N = -174 + 10 log 10(Rb) -120. 02 d. Bm 7 d. B -113. 02 d. Bm Minimum Eb/N 0 (S) 13 d. B 16 d. B Implementation Loss (I) 5 d. B Link Margin (M = PR - PN – S – I) 10. 64 d. B 7. 64 d. B Proposed Min. Rx Sensitivity Level -95. 02 d. Bm -92. 02 d. Bm Parameter Peak Payload bit rate (Rb) Average Tx Power Gain (PT) Tx antenna gain (GT) f’c: (geometric frequency) Path Loss @ 1 m: L 1 = 20 log 10(4. . f’c / c) Path Loss @ d m: L 2 = 20 log 10(d) Rx Antenna Gain (GR) Rx noise figure (NF) Average noise power per bit (PN = N + NF) Slide 50 CWC/AETHERWIRE/CEA-LETI/STM/MERL

Mar. 2005 doc. : IEEE 802. 15 -05 -0130 -01 -004 a Outline • • • • Introduction Background Transmitted Signal Receiver Architectures Bandwidth Usage Optional Aspects System performances Link budget Framing, throughput Power Saving Ranging and Delay Estimation Feasibility Conclusions Slide 51 CWC/AETHERWIRE/CEA-LETI/STM/MERL

Mar. 2005 doc. : IEEE 802. 15 -05 -0130 -01 -004 a Framing – 802. 15. 4 Compatible Octets PHY layer 4 1 1 32 Preamble SFD Frame length PSDU = MPDU PHR PSDU (PHY Service Data Unit) SHR PPDU (PHY Protocol Data Unit) Beacon slot 0 BP 1 2 CAP slot 3 4 5 CAP 6 7 CFP slot 8 BP : Beacon Period CAP : Contention Access Period CFP : Contention Free Period IP : Inactive Period (optional) 9 10 11 12 13 14 15 CFP IP Superframe Duration Beacon Interval Slide 52 CWC/AETHERWIRE/CEA-LETI/STM/MERL

Mar. 2005 doc. : IEEE 802. 15 -05 -0130 -01 -004 a Throughput Data Frame (32 octet PSDU) Bytes 4 PHY layer Preamble SHR 1 1 32 SFD Frame length PSDU = MPDU PHR PSDU (PHY Service Data Unit) ACK Frame (5 octet PSDU) Bytes PHY layer Preamble • 1 1 5 SFD Frame length PSDU PHR PSDU SHR PPDU (PHY Protocol Data Unit) Tdata 4 PPDU (PHY Protocol Data Unit) T_ACK Tack IFS Numerical example (high-band) • • • Þ Þ Preamble + SFD + PHR = 6 octets Tdata = 1. 216 ms T_ACK = 50 ms (turn around time requested by IEEE 802. 15. 4 is 192 ms) Tack = 0. 352 ms IFS = 100μs Throughput = 32 octets/1. 718 ms = 149 kb/s Average data-rate at receiver PHY-SAP 250 kb/s (Basic Mode) Slide 53 CWC/AETHERWIRE/CEA-LETI/STM/MERL

Mar. 2005 doc. : IEEE 802. 15 -05 -0130 -01 -004 a Outline • • • • Introduction Background Transmitted Signal Receiver Architectures Bandwidth Usage Optional Aspects System performances Link budget Framing, throughput Power Saving Ranging and Delay Estimation Feasibility Conclusions Slide 54 CWC/AETHERWIRE/CEA-LETI/STM/MERL

Mar. 2005 doc. : IEEE 802. 15 -05 -0130 -01 -004 a Saving Power • Power Saving techniques achieved by combining advantages offered at 3 levels: – Technology (best if CMOS) – Architecture (flexible schemes provided by the TH+pulse modulation) – System level (framing, protocol usage) • Selected techniques used in one existing realization (see proof of concept slides) – Low-duty cycle Episodic transmission/reception • Scheduled wake-up • 80 ms RTOS tick – Ad-hoc networking using multi-hop • Special rapid acquisition codes / algorithm • Matchmaking further reduces acquisition time – Multi-stage time-of-day clock • Synchronous counter / current mode logic for highest speed stages • Ripple counter / static CMOS for lowest speed stages – Compute-intensive correlation done in hardware Slide 55 CWC/AETHERWIRE/CEA-LETI/STM/MERL

Mar. 2005 doc. : IEEE 802. 15 -05 -0130 -01 -004 a Outline • • • • Introduction Background Transmitted Signal Receiver Architectures Bandwidth Usage Optional Aspects System performances Link budget Framing, throughput Power Saving Ranging and Delay Estimation Feasibility Conclusions Slide 56 CWC/AETHERWIRE/CEA-LETI/STM/MERL

Mar. 2005 doc. : IEEE 802. 15 -05 -0130 -01 -004 a Ranging • Motivation : – Benefit from high time resolution (thanks to signal bandwidth): • Theoretically: 2 GHz provides less than 20 cm resolution • Practically: Impairments, low cost/complexity devices should support ~50 cm accuracy with simple detection strategies (better with high resolution techniques) • Approach : – Use Two Way Ranging between 2 devices with no network constraint (preferred); no need for time synchronization among nodes – Use One Way Ranging and TDOA under some network constraints (if supported) Slide 57 CWC/AETHERWIRE/CEA-LETI/STM/MERL

Mar. 2005 doc. : IEEE 802. 15 -05 -0130 -01 -004 a TOA Delay Estimation - Non-Coherent • Use bank of integrators to determine coarse synchronisation “uncertainty” region – • Symbol synchronisation “uncertainty” region given by coarse synchronisation ( e. g. , 4 ns-20 ns) A refinement search is applied onto the uncertainty region by either – further dividing it into narrower non overlapping regions for non-coherent refinement (e. g. , 1 ns –> 4 ns) or – Coherent search with a template correlation Integrator outputs Energy Analyzer TRB: the length of uncertainty region Detects the coarse “uncertainty region” Leading Edge Search Refinement Performed within the selected uncertainty region Range info Slide 58 CWC/AETHERWIRE/CEA-LETI/STM/MERL

Mar. 2005 doc. : IEEE 802. 15 -05 -0130 -01 -004 a TOA Delay Estimation - Non-Coherent (cont’d) • • The algorithm selects the maximum value integration window index and then it searches backward to find the first integration value which crosses an adaptively set threshold. If there are no values crossing the threshold, the peak position is used for the TOA estimation. MES-SB based TOA Estimate Searchback window Strongest Path, energy block Threshold based TOA Estimate Threshold N 0 1 2 Actual TOA Contains leading edge MES: Maximum Energy Search TC: Threshold comparison SB: Search Back MES based TOA Estimate Slide 59 CWC/AETHERWIRE/CEA-LETI/STM/MERL

Mar. 2005 doc. : IEEE 802. 15 -05 -0130 -01 -004 a ENERGY Spread in CM 1 • PDF of TOA estimation errors are illustrated for MES at various Eb. N 0 – CM 1, integration interval 4 ns, Tf=200 ns (results will be updated for Tf=240 ns) Slide 60 CWC/AETHERWIRE/CEA-LETI/STM/MERL

Mar. 2005 doc. : IEEE 802. 15 -05 -0130 -01 -004 a Ranging Simulation Settings Notations and Terms Definition Value in Simulations Tf Pulse repetition interval, frame 200 ns Nb Number of blocks within a Tf 50 Nc Number of refinement intervals within a Tf 400 TH{} Time hopping sequence in chips {h 1, . . , h 5} POL{} Polarity codes {p 1, . . . , p 5} N 1 Number of frames in the 1 st-step 50 N 2 Number of frames in the refinement 30 BW Bandwidth C 2 GHz Number of correlators (refinement stage) 10 Note: Results are to be provided when Tf is set to 240 ns. Slide 61 CWC/AETHERWIRE/CEA-LETI/STM/MERL

Mar. 2005 doc. : IEEE 802. 15 -05 -0130 -01 -004 a Ranging Results • IEEE 802. 15. 4 a CM 1 -Residential LOS True Distance (m) One-way ranging error (confidence level) 25 m 8 cm (97%) 30 m 8 cm (~90%) Round Trip ranging error (with no drift compensation) – ~16 cm (0. 088 ms), no clock drift – ~17. 1 cm (1 ppm) – ~20. 1 cm (4 ppm) – ~26 cm (10 ppm) – ~56 cm (40 ppm) Slide 62 CWC/AETHERWIRE/CEA-LETI/STM/MERL

Mar. 2005 Two Way Ranging (TWR) doc. : IEEE 802. 15 -05 -0130 -01 -004 a Main Limitations / Impact of Clock Drift on Perceived Time Is the frequency offset relative to the nominal ideal frequency Range estimation is affected by : • Relative clock drift between A and B 250 kbps, 38 bytes PPDU 500 kbps, 9 bytes PPDU • Prescribed response delay Df/f Treply (max error) 1408 ms 1226 ms 336 ms 154 ms • Clock accuracy in A and B 4 ppm 1. 69 m 1. 47 m 0. 40 m 0. 18 m 25 ppm 10. 56 m 9. 19 m 2. 52 m 1. 15 m 40 ppm 16. 9 m 14. 7 m 4. 0 m 1. 8 m • Channel response (weak direct path) Example using Imm-ACK SIFS of 15. 4 and 15. 3 of respectively 192 us and 10 us and PPDU size of respectively 38 and 9 bytes Simple immediate TWR made unusable with reasonnable crystal accuracies. Solution is : • Performing fine drift estimation/compensation • Benefiting from cooperative transactions Slide (estimated clock ratios …) CWC/AETHERWIRE/CEA-LETI/STM/MERL 63

Mar. 2005 doc. : IEEE 802. 15 -05 -0130 -01 -004 a Outline • • • • Introduction Background Transmitted Signal Receiver Architectures Bandwidth Usage Optional Aspects System performances Link budget Framing, throughput Power Saving Ranging and Delay Estimation Feasibility Conclusions Slide 64 CWC/AETHERWIRE/CEA-LETI/STM/MERL

Mar. 2005 doc. : IEEE 802. 15 -05 -0130 -01 -004 a Antenna Feasibility Capacitive Dipole and Various Bowtie Antennas 55 mm 40 mm Bowtie antenna Slide 65 CWC/AETHERWIRE/CEA-LETI/STM/MERL

Mar. 2005 doc. : IEEE 802. 15 -05 -0130 -01 -004 a “Proof-of-Concept” (1) Non-coherent Transceiver Non-coherent, Energy Collection Receiver 5 Mbps BPPM 350 ps pulse train with long scrambling code Slide 66 CWC/AETHERWIRE/CEA-LETI/STM/MERL

Mar. 2005 doc. : IEEE 802. 15 -05 -0130 -01 -004 a “Proof-of-Concept” (2) Non-coherent Transceiver UWB-IR BPPM Non-Coherent Transceiver Implementation UWB Transmitter 400 μm x 400 μm 0. 35 μm CMOS UWB Transceiver Test architecture <10 mm 2 0. 35 μm Si. Ge Bi-CMOS Slide 67 CWC/AETHERWIRE/CEA-LETI/STM/MERL

Mar. 2005 doc. : IEEE 802. 15 -05 -0130 -01 -004 a “Proof-of-Concept” (3): Transmitter - Lower Band P-Channel Drivers Delay Buffers N-Channel Drivers N-C UWB Transmitter chip for generating impulse doublets Slide 68 CWC/AETHERWIRE/CEA-LETI/STM/MERL

Mar. 2005 doc. : IEEE 802. 15 -05 -0130 -01 -004 a VGC Amp DACs 32 Time-Integrating Correlators PLL Loop Filter DACs Code Sequence Generators “Rails” for testing analog circuits LF RTC High-Frequency Real Time Clock “Proof-of-Concept” (4): Receiver - Lower Band Coherent UWB Receiver with multiple time integrating correlators Slide 69 CWC/AETHERWIRE/CEA-LETI/STM/MERL

Mar. 2005 doc. : IEEE 802. 15 -05 -0130 -01 -004 a “Proof-of-Concept” (5) High Speed Coherent Circuit Elements RF front end chips in CMOS 0. 13 mm, 1. 2 V 20 GHz digitizer for UWB 20 GHz DLL for UWB 3 -5 GHz LNA Chip and layout Slide 70 CWC/AETHERWIRE/CEA-LETI/STM/MERL

Mar. 2005 doc. : IEEE 802. 15 -05 -0130 -01 -004 a Outline • • • • Introduction Background Transmitted Signal Receiver Architectures Bandwidth Usage Optional Aspects System performances Link budget Framing, throughput Power Saving Ranging and Delay Estimation Feasibility Conclusions Slide 71 CWC/AETHERWIRE/CEA-LETI/STM/MERL

Mar. 2005 doc. : IEEE 802. 15 -05 -0130 -01 -004 a Conclusions • Proposal based upon UWB impulse radio – High time resolution suitable for precise ranging using TOA – Modulation: • • • Pulse-shape independent Robust under SOP operation Facilitates synchronization/tracking Supports multiple coherent/non-coherent RX architectures System tradeoffs – Modulation optimized for several aspects (requirements, performances, flexibility, technology) – Trade-off complexity/performance RX • Flexible implementation of the receiver – Coherent, differential, non-coherent (energy collection) – Analogue, digital • Fits with multiple technologies – Easy implementation in CMOS – Very low power solution (technology, architecture, system level) Slide 72 CWC/AETHERWIRE/CEA-LETI/STM/MERL

Mar. 2005 doc. : IEEE 802. 15 -05 -0130 -01 -004 a Backup Slides Slide 73 CWC/AETHERWIRE/CEA-LETI/STM/MERL

Mar. 2005 doc. : IEEE 802. 15 -05 -0130 -01 -004 a BER Performance in AWGN Channel 10 -1 MRC Solution (coherent) Differential Solution Energy Collection solution in OOK Transmitted Reference (one pulse) BER 10 -2 10 -3 10 -4 10 -5 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Eb/N 0 -3 d. B : the “reference” is not in the same PRP ! PER = 1% with 32 bytes PSDU acceptable BER 4 x 10 -5 with no channel coding Slide 74 CWC/AETHERWIRE/CEA-LETI/STM/MERL

Mar. 2005 doc. : IEEE 802. 15 -05 -0130 -01 -004 a BER Performance in AWGN Channel Slide 75 CWC/AETHERWIRE/CEA-LETI/STM/MERL

Mar. 2005 doc. : IEEE 802. 15 -05 -0130 -01 -004 a Antenna Practicality • Bandwidth: 3 GHz-10 GHz • Form factor • Omni-directional z antenna hat Ø 24 mm q 7 mm y j x Slide 76 ground plane Ø 80 mm CWC/AETHERWIRE/CEA-LETI/STM/MERL

Mar. 2005 doc. : IEEE 802. 15 -05 -0130 -01 -004 a Positioning from TDOA Anchor 3 3 anchors with known positions (at least) are required to find a 2 D-position from a couple of TDOAs (x. A 3, y. A 3) Anchor 2 (x. A 2, y. A 2) Mobile Measurements (xm, ym) Estimated Position Specific Positioning Algorithms Slide 77 Anchor 1 (x. A 1, y. A 1) CWC/AETHERWIRE/CEA-LETI/STM/MERL

Mar. 2005 doc. : IEEE 802. 15 -05 -0130 -01 -004 a TR BPPM Scheme Comparison Slide 78 CWC/AETHERWIRE/CEA-LETI/STM/MERL

Mar. 2005 doc. : IEEE 802. 15 -05 -0130 -01 -004 a Assumptions and Notes • Results are theoretical calculations • Assumes ideal ”impulse” UWB pulses in AWGN channel • Different TR-BBP options are considered with different number of pulses per pulse train • Multipath fading simulations can be performed to back up theory Slide 79 CWC/AETHERWIRE/CEA-LETI/STM/MERL

Mar. 2005 doc. : IEEE 802. 15 -05 -0130 -01 -004 a Pulse repetition structures TR BPPM with doublets (Scheme 1) Slide 80 CWC/AETHERWIRE/CEA-LETI/STM/MERL

Mar. 2005 doc. : IEEE 802. 15 -05 -0130 -01 -004 a Pulse repetition structures TR BPPM single reference (Scheme 2) Slide 81 CWC/AETHERWIRE/CEA-LETI/STM/MERL

Mar. 2005 doc. : IEEE 802. 15 -05 -0130 -01 -004 a Pulse repetition structures Auto Correlation BPPM with doublets (Scheme 3) Slide 82 CWC/AETHERWIRE/CEA-LETI/STM/MERL

Mar. 2005 doc. : IEEE 802. 15 -05 -0130 -01 -004 a Pulse repetition structures Auto Correlation BPPM single reference (Scheme 4) Slide 83 CWC/AETHERWIRE/CEA-LETI/STM/MERL

Mar. 2005 doc. : IEEE 802. 15 -05 -0130 -01 -004 a Pulse repetition structures Auto Correlation BPPM alternate (Scheme 5) Slide 84 CWC/AETHERWIRE/CEA-LETI/STM/MERL

Mar. 2005 doc. : IEEE 802. 15 -05 -0130 -01 -004 a Parameters • PPI slot - slot inside each TH chip containing a burst of pulses including reference pulses (ref. slides from Laurent / CEA) • Np represents the number of pulses in each PPI slot • The energy E per PPI slot is kept constant • The pulse energy Ep = E/Np • TW represent the time-bandwidth product Slide 85 CWC/AETHERWIRE/CEA-LETI/STM/MERL

Mar. 2005 doc. : IEEE 802. 15 -05 -0130 -01 -004 a Ep/N 0 degradation versus number of pulses per pulse train Slide 86 CWC/AETHERWIRE/CEA-LETI/STM/MERL

Mar. 2005 doc. : IEEE 802. 15 -05 -0130 -01 -004 a Ep/N 0 degradation versus Time/Bandwidth product Slide 87 CWC/AETHERWIRE/CEA-LETI/STM/MERL

Mar. 2005 doc. : IEEE 802. 15 -05 -0130 -01 -004 a Ep/N 0 degradation versus number of pulses per pulse train Slide 88 CWC/AETHERWIRE/CEA-LETI/STM/MERL

Mar. 2005 doc. : IEEE 802. 15 -05 -0130 -01 -004 a Conclusions • Scheme 5 - “AC Alternate” performs better then all the other pulse repetition structures. • AC generally performs better than TR • “AC alternate” and “AC with doublets” have the advantage of requiring only a single delay line. • Scheme 5 - “AC Alternate”, was proposed at Monterey meeting in January. • Criticism was given based on ”accumulated noise” in noisecross-noise-cross-noise. . . Products”. • Seems to outperform other schemes with simple analysis • Also more readily implementable since fixed delay line can be used. Slide 89 CWC/AETHERWIRE/CEA-LETI/STM/MERL

Mar. 2005 doc. : IEEE 802. 15 -05 -0130 -01 -004 a Channel / Delay Estimation Coherent Approach Slide 90 CWC/AETHERWIRE/CEA-LETI/STM/MERL

Mar. 2005 doc. : IEEE 802. 15 -05 -0130 -01 -004 a Channel / Delay Estimation Coherent Approach • Swept delay correlator • Principle: estimating only one channel sample per symbol. Similar concept as STDCC channel sounder of Cox (1973). • Sampler, AD converter operating at SYMBOL rate (1. 2 Msamples/s) • Requires longer training sequence • Two-step procedure for estimating coefficients: – With lower accuracy: estimate at which taps energy is significant – With higher accuracy: determine tap weights • “Silence periods”: for estimation of interference Slide 91 CWC/AETHERWIRE/CEA-LETI/STM/MERL

Mar. 2005 doc. : IEEE 802. 15 -05 -0130 -01 -004 a Optimal Energy-Threshold Analysis (CM-1) • Optimal normalized threshold (normalized with respect to the difference between the maximum and minimum energy blocks) changes with Eb/N 0 and block size. • Smaller thresholds are required in general at high Eb/N 0, while larger thresholds at lower SNR values MAE Mean Absolute Error in detecting leading energy block with simple threshold crossing (1000 channel realizations) Eb/N 0 : {8 --- 26 d. B} Slide 92 CWC/AETHERWIRE/CEA-LETI/STM/MERL