1. Mar. 2005 CWC/AETHERWIRE/CEA-LETI/STM/MERL doc.: IEEE 802. 15-05-xxxx-00-004a Slide 1 Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs) Submission Title: STM_CEA-LETI_CWC_AETHERWIRE_MITSUBISHI 15.4aCFP response Date Submitted: January 4th, 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) 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 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, rrober14@harris.com, {vern.brethour, adrian.jennings}@timedomain.com Abstract: UWB proposal for 802.15.4a alt-PHY Purpose: Proposal based on UWB impulse radio for the IEEE 802.15.4a CFP 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 contributors acknowledge and accept that this contribution becomes the property of IEEE and may be made publicly available by P802.15

2. Mar. 2005 CWC/AETHERWIRE/CEA-LETI/STM/MERL doc.: IEEE 802. 15-05-xxxx-00-004a Slide 2 List of Authors CWC – Ian Oppermann, Alberto Rabbachin (1) AetherWire – 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)

3. Mar. 2005 CWC/AETHERWIRE/CEA-LETI/STM/MERL doc.: IEEE 802. 15-05-xxxx-00-004a Slide 3 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

4. Mar. 2005 CWC/AETHERWIRE/CEA-LETI/STM/MERL doc.: IEEE 802. 15-05-xxxx-00-004a Slide 4 Proposal Main Features 1.Impulse-radio based (pulse-shape independent) 2.Support for different receiver architectures (coherent/non- coherent) 3.Flexible modulation format 4.Support for multiple rates 5.Enables accurate ranging/positioning 6.Support for multiple SOP

5. Mar. 2005 CWC/AETHERWIRE/CEA-LETI/STM/MERL doc.: IEEE 802. 15-05-xxxx-00-004a Slide 5 Motivation for (2-4): Supports homogenous and heterogeneous network architectures Different classes of nodes, with different reliability requirements (and cost) must inter-work

6. Mar. 2005 CWC/AETHERWIRE/CEA-LETI/STM/MERL doc.: IEEE 802. 15-05-xxxx-00-004a Slide 6 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

7. Mar. 2005 CWC/AETHERWIRE/CEA-LETI/STM/MERL doc.: IEEE 802. 15-05-xxxx-00-004a Slide 7 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

8. Mar. 2005 CWC/AETHERWIRE/CEA-LETI/STM/MERL doc.: IEEE 802. 15-05-xxxx-00-004a Slide 8 Commonalities with Other Proposals Many commonalities exist between the CWC/Aetherwire/LETI/STM/MERL proposal and other proposals, including FT : – UWB technology – Modulation features – Bandwidth usage – Ranging approach Discussions are under way for future collaborations and merging

9. Mar. 2005 CWC/AETHERWIRE/CEA-LETI/STM/MERL doc.: IEEE 802. 15-05-xxxx-00-004a Slide 9 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

10. Mar. 2005 CWC/AETHERWIRE/CEA-LETI/STM/MERL doc.: IEEE 802. 15-05-xxxx-00-004a Slide 10 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

11. Mar. 2005 CWC/AETHERWIRE/CEA-LETI/STM/MERL doc.: IEEE 802. 15-05-xxxx-00-004a Slide 11 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 3dB for transmitted reference (not for DPSK) Non-coherent + : Low complexity + : Acquisition speed - : Sensitivity, robustness to SOP and interferers

12. Mar. 2005 CWC/AETHERWIRE/CEA-LETI/STM/MERL doc.: IEEE 802. 15-05-xxxx-00-004a Slide 12 Time Hopping Impulse Radio (TH-IR) - Principle TsTs TcTc TfTf +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

13. Mar. 2005 CWC/AETHERWIRE/CEA-LETI/STM/MERL doc.: IEEE 802. 15-05-xxxx-00-004a Slide 13 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

14. Mar. 2005 CWC/AETHERWIRE/CEA-LETI/STM/MERL doc.: IEEE 802. 15-05-xxxx-00-004a Slide 14 Transmitted Reference TsTs TcTc TfTf TdTd +1 First pulse serves as template for estimating channel distortions Second pulse carries information Drawback: Waste of 3dB energy on reference pulses reference data

15. Mar. 2005 CWC/AETHERWIRE/CEA-LETI/STM/MERL doc.: IEEE 802. 15-05-xxxx-00-004a Slide 15 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

16. Mar. 2005 CWC/AETHERWIRE/CEA-LETI/STM/MERL doc.: IEEE 802. 15-05-xxxx-00-004a Slide 16 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 40ns (first realization) and 125ns (second realizations). Higher values for the frame duration have been mentioned. Further discussions are required to fix the values

17. Mar. 2005 CWC/AETHERWIRE/CEA-LETI/STM/MERL doc.: IEEE 802. 15-05-xxxx-00-004a Slide 17 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)  TH code length 8 or 16 TH code : binary position (delay of 0 or τ Δ ), bi-phase For first realization, higher-order TH with shorter chip duration (multiples of 2ns) can be used. This is under discussion Design Parameters (2)

18. Mar. 2005 CWC/AETHERWIRE/CEA-LETI/STM/MERL doc.: IEEE 802. 15-05-xxxx-00-004a Slide 18 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

19. Mar. 2005 CWC/AETHERWIRE/CEA-LETI/STM/MERL doc.: IEEE 802. 15-05-xxxx-00-004a Slide 19 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.

20. Mar. 2005 CWC/AETHERWIRE/CEA-LETI/STM/MERL doc.: IEEE 802. 15-05-xxxx-00-004a Slide 20 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

21. Mar. 2005 CWC/AETHERWIRE/CEA-LETI/STM/MERL doc.: IEEE 802. 15-05-xxxx-00-004a Slide 21 First Realization

22. Mar. 2005 CWC/AETHERWIRE/CEA-LETI/STM/MERL doc.: IEEE 802. 15-05-xxxx-00-004a Slide 22 Second Realization Ts « 11 » « 01 » 2-PPM + TR base M = 2 (with two bits/symbol) One bit/symbol also Possible !!! « 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

23. Mar. 2005 CWC/AETHERWIRE/CEA-LETI/STM/MERL doc.: IEEE 802. 15-05-xxxx-00-004a Slide 23 Mitigation of peak voltage through multi pulses Tf=PPI IS « EQUIVALENT » TO ppV = peak-to-peak voltage ppV/2 M = 4 M = 1 Tf=PPI ppV/sqrt(2) M = 2

24. Mar. 2005 CWC/AETHERWIRE/CEA-LETI/STM/MERL doc.: IEEE 802. 15-05-xxxx-00-004a Slide 24 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/non- coherent receivers

25. Mar. 2005 CWC/AETHERWIRE/CEA-LETI/STM/MERL doc.: IEEE 802. 15-05-xxxx-00-004a Slide 25 Basic Properties Use of Doublets with memory from previous bit. (Encoding of reference pulse with previous bit) – Agreed on 20ns 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

26. Mar. 2005 CWC/AETHERWIRE/CEA-LETI/STM/MERL doc.: IEEE 802. 15-05-xxxx-00-004a Slide 26 TsTs Differential Encoding of Bits +1 -1 +1 -1 +1 -1 -1 -1 +1 +1 -1 -1 0 0 1 1 0 0 1 b0b0 b4b4 b3b3 b2b2 b1b1 b5b5 b -1 Tx Bits Reference Polarity 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.

27. Mar. 2005 CWC/AETHERWIRE/CEA-LETI/STM/MERL doc.: IEEE 802. 15-05-xxxx-00-004a Slide 27 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

28. Mar. 2005 CWC/AETHERWIRE/CEA-LETI/STM/MERL doc.: IEEE 802. 15-05-xxxx-00-004a Slide 28 Higher-order modulation TH Pattern TH Code 1,1 1,1 0,1 0,0 1,0 0,1 Data 1,1 1,1 1,1 1,1 1,1 0,0 Pulse Shift, polarity invert τ Δ + τ delay Enhanced Mode 1 D « 1 1 » « 1 0 » DD τ delay + τ Δ τΔτΔ τ delay τ Δ + τ delay τ delay τΔτΔ τ Δ + τ delay Basic Mode (as seen by non-coherent) « 1 » τ delay + τ Δ D DD

29. Mar. 2005 CWC/AETHERWIRE/CEA-LETI/STM/MERL doc.: IEEE 802. 15-05-xxxx-00-004a Slide 29 Comments on Transmitted Signal Frame period for solution 2 is T frame = (N p * D) + τ Δ + τ delay – Τ delay 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 T frame – 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)

30. Mar. 2005 CWC/AETHERWIRE/CEA-LETI/STM/MERL doc.: IEEE 802. 15-05-xxxx-00-004a Slide 30 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

31. Mar. 2005 CWC/AETHERWIRE/CEA-LETI/STM/MERL doc.: IEEE 802. 15-05-xxxx-00-004a Slide 31 Proposed RAKE -- Coherent Receiver Rake Receiver Finger Np Demultiplexer Rake Receiver Finger 2 Rake Receiver Finger 1 Summer Channel Estimation Convolutional Decoder Data Sink Sequence Detector 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

32. Mar. 2005 CWC/AETHERWIRE/CEA-LETI/STM/MERL doc.: IEEE 802. 15-05-xxxx-00-004a Slide 32 Proposed Transmitted Reference Receiver – Differentially Coherent TdTd Matched Filter Convolutional Decoder Addition of Matched Filter prior to delay and correlate operations improves output signal to noise ratio and reduces noise-noise cross terms SNR of decision statistic

33. Mar. 2005 CWC/AETHERWIRE/CEA-LETI/STM/MERL doc.: IEEE 802. 15-05-xxxx-00-004a Slide 33 Band Matched LNALNA BPF Tracking Threshol ds setting Tracking DumpLatchDumpLatch RAZ DUMP ControlledIntegrator ADC BPPM Demodulation branch RAZ Differentially-Coherent/Non-Coherent Receiver Architecture Basic Mode and Enhanced Mode 1 x 2 r(t) Recyle this branch for Enhanced Data Rate Modes DelayDelay TR Demodulation branch DumpLatchDumpLatch ADC ControlledIntegrator BPPM Synch Trigger TR Energy Analyzer Block index for acquisition reference Leading-edge refinement search Range info Ranging branch

34. Mar. 2005 CWC/AETHERWIRE/CEA-LETI/STM/MERL doc.: IEEE 802. 15-05-xxxx-00-004a Slide 34 Band Matched LNALNA BPF De-spreading TH Codes r(t) TH Sequence Matched Filter Bit Demodulation Band Matched LNALNA BPF r(t) TH Sequence Matched Filter Bit Demodulation Case I - Coherent TH despreading ADC ADC b(t) soft info Case II – Non-coherent / differential TH despreading

35. Mar. 2005 CWC/AETHERWIRE/CEA-LETI/STM/MERL doc.: IEEE 802. 15-05-xxxx-00-004a Slide 35 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

36. Mar. 2005 CWC/AETHERWIRE/CEA-LETI/STM/MERL doc.: IEEE 802. 15-05-xxxx-00-004a Slide 36 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 Use of TH and/or polarity randomization for spectral smoothing Different bandwidth use options being considered

37. Mar. 2005 CWC/AETHERWIRE/CEA-LETI/STM/MERL doc.: IEEE 802. 15-05-xxxx-00-004a Slide 37 Bandwidth Usage – 2GHz option (2/4) 0.96 3.1 5.1 6.0 8.0 8.1 10.1 GHz ISM Band Upper Band 1 Upper Band 2 Upper Band 3 Lower band ISM Band

38. Mar. 2005 CWC/AETHERWIRE/CEA-LETI/STM/MERL doc.: IEEE 802. 15-05-xxxx-00-004a Slide 38 Bandwidth Usage -500 MHz Option (3/4) 0.96 3.1 5.1 6.0 8.0 8.1 10.1 GHz ISM Band Lower band ISM Band Upper Bands 1 - 4 Upper Bands 5 - 12

39. Mar. 2005 CWC/AETHERWIRE/CEA-LETI/STM/MERL doc.: IEEE 802. 15-05-xxxx-00-004a Slide 39 Bandwidth Usage –Variable Option (4/4) 0.96 3.1 5.1 6.0 8.0 8.1 10.1 GHz ISM Band Lower band ISM Band Upper Bands 1 - 4 Upper Bands 5 - 12

40. Mar. 2005 CWC/AETHERWIRE/CEA-LETI/STM/MERL doc.: IEEE 802. 15-05-xxxx-00-004a Slide 40 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

41. Mar. 2005 CWC/AETHERWIRE/CEA-LETI/STM/MERL doc.: IEEE 802. 15-05-xxxx-00-004a Slide 41 Spectral Shaping & Interference Suppression (Optional) Basis pulse: use simple pulse shape gaussian, raised cosine, chaotic, etc. Drawbacks: – Possible loss of power compared to FCC- allowed power – Strong radiation at 2.45 and 5.2 GHz frequency (Hz) Monocycle, 5 th derivative of gaussian pulse Power spectral density of the monocycle 10log 10 |P(f)| 2 dB

42. Mar. 2005 CWC/AETHERWIRE/CEA-LETI/STM/MERL doc.: IEEE 802. 15-05-xxxx-00-004a Slide 42 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

43. Mar. 2005 CWC/AETHERWIRE/CEA-LETI/STM/MERL doc.: IEEE 802. 15-05-xxxx-00-004a Slide 43 Spectral Shaping & Polarity Scrambling T d = 10 ns T d = 20 ns W/ Polarity ScramblingW/O Polarity Scrambling

44. Mar. 2005 CWC/AETHERWIRE/CEA-LETI/STM/MERL doc.: IEEE 802. 15-05-xxxx-00-004a Slide 44 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

45. Mar. 2005 CWC/AETHERWIRE/CEA-LETI/STM/MERL doc.: IEEE 802. 15-05-xxxx-00-004a Slide 45 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

46. Mar. 2005 CWC/AETHERWIRE/CEA-LETI/STM/MERL doc.: IEEE 802. 15-05-xxxx-00-004a Slide 46 PER in 15.4a Channel Model Non-Coherent (Energy Collection) BPPM Framing format: Preamble (32 bits) SFD (8 bits) LEN MHR+MSDU (240 bits) CRC (16 bits) Simulations over 1000 channel responses BW = 2GHz – Integration Time = 80ns Implementation loss + Noise figure margin : 11 dB Max range is determined from:  Required Eb/N0,  Implementation margin  Path loss characteristics X1 (CM8)X2 (CM1)X3 (CM5)X4 (CM9) Required Eb/N019.5 dB20 dB21 dB21.5 dB Max Range (I)10.78 m84.61 m86.72 m58.67 m Max Range (II)7.33 m53.25 m54.15 m34.72 m Case I: 250 kbps – PRP 250 ns with 16 pre-integrations = 4 µs Case II: 250 kbps – PRP 500 ns with 8 post-integrations

47. Mar. 2005 CWC/AETHERWIRE/CEA-LETI/STM/MERL doc.: IEEE 802. 15-05-xxxx-00-004a Slide 47 PER/BER in 15.4a Channel Model DBPSK (RAKE) X1 (CM8)X2 (CM1)X3 (CM5)X4 (CM9) Required Eb/N018 dB17.5 dB18.5 dB Max Range (I)12.66 m116.70 m120.27 m90.84 m Max Range (II)9.18 m79.34 m81.23 m58.67 m Implementation loss and Noise figure margin : 11 dB Theoretical BER Curves – Integration Time = 50 ns Case I: 250 kbps – PRP 250 ns with 16 pre-integration = 4 µs Case II: 250 kbps – PRP 500 ns with 8 post-integrations

48. Mar. 2005 CWC/AETHERWIRE/CEA-LETI/STM/MERL doc.: IEEE 802. 15-05-xxxx-00-004a Slide 48 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

49. Mar. 2005 CWC/AETHERWIRE/CEA-LETI/STM/MERL doc.: IEEE 802. 15-05-xxxx-00-004a Slide 49 Link Budget: Non-Coherent (Energy Collection) BPPM Parameter Mandatory Value (PRP = 4 µs) Optional Value (PRP = 500ns - 8 integrations) Peak Payload bit rate (R b )250 kb/s Average Tx Power Gain (P T )-10.64 dBm Tx antenna gain (G T )0 dBi f’c: (geometric frequency)3.873 GHz Path Loss @ 1m: L 1 = 20log10(4. .f’ c / c) 44.20 dB Path Loss @ d m: L 2 = 20log10(d)29.54 dB @ d = 30 m Rx Antenna Gain (G R )0 dBi Rx Power (P R = P T + G T + G R – L 1 – L 2 )-84.38 dBm Average noise power per bit: N = -174 + 10log 10 (Rb)-120.02 dBm Rx noise figure (N F )7 dB Average noise power per bit (P N = N + N F )-113.02 dBm Minimum E b /N 0 (S)14 dB17.6 dB Implementation Loss (I)5 dB Link Margin (M = P R - P N – S – I)9.64 dB6.04 dB Proposed Min. Rx Sensitivity Level-94.02 dBm-90.42 dBm

50. Mar. 2005 CWC/AETHERWIRE/CEA-LETI/STM/MERL doc.: IEEE 802. 15-05-xxxx-00-004a Slide 50 Link Budget: DBPSK (RAKE) Parameter Mandatory Value (PRP = 4 µs) Optional Value (PRP = 500ns - 8 integrations) Peak Payload bit rate (R b )250 kb/s Average Tx Power Gain (P T )-10.64 dBm Tx antenna gain (G T )0 dBi f’c: (geometric frequency)3.873 GHz Path Loss @ 1m: L 1 = 20log10(4. .f’ c / c) 44.20 dB Path Loss @ d m: L 2 = 20log10(d)29.54 dB @ d = 30 m Rx Antenna Gain (G R )0 dBi Rx Power (P R = P T + G T + G R – L 1 – L 2 )-84.38 dBm Average noise power per bit: N = -174 + 10log 10 (Rb)-120.02 dBm Rx noise figure (N F )7 dB Average noise power per bit (P N = N + N F )-113.02 dBm Minimum E b /N 0 (S)13 dB16 dB Implementation Loss (I)5 dB Link Margin (M = P R - P N – S – I)10.64 dB7.64 dB Proposed Min. Rx Sensitivity Level-95.02 dBm-92.02 dBm

51. Mar. 2005 CWC/AETHERWIRE/CEA-LETI/STM/MERL doc.: IEEE 802. 15-05-xxxx-00-004a Slide 51 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

52. Mar. 2005 CWC/AETHERWIRE/CEA-LETI/STM/MERL doc.: IEEE 802. 15-05-xxxx-00-004a Slide 52 Framing – 802.15.4 Compatible CAPCFPIPBP Beacon Interval BP : Beacon Period CAP : Contention Access Period CFP : Contention Free Period IP : Inactive Period (optional) Superframe Duration Beacon slotCAP slotCFP slot 0123456789101112131415 PreambleSFDPSDU = MPDUPHY layer PPDU (PHY Protocol Data Unit) PSDU (PHY Service Data Unit)SHR Octets 3241 Frame length PHR 1

53. Mar. 2005 CWC/AETHERWIRE/CEA-LETI/STM/MERL doc.: IEEE 802. 15-05-xxxx-00-004a Slide 53 Throughput PreambleSFDPSDU = MPDUPHY layer PPDU (PHY Protocol Data Unit) PSDU (PHY Service Data Unit)SHR Bytes 3241 Frame length PHR 1 PreambleSFDPSDUPHY layer PPDU (PHY Protocol Data Unit) PSDUSHR Bytes 541 Frame length PHR 1 Data Frame (32 octet PSDU)ACK Frame (5 octet PSDU) TdataTackT_ACK Numerical example (high-band) Preamble + SFD + PHR = 6 octets Tdata = 1.216 ms T_ACK = 50  s (turn around time requested by IEEE 802.15.4 is 192  s) Tack = 0.352 ms IFS = 100 μs  Throughput = 32 octets/1.718 ms = 149 kb/s  Average data-rate at receiver PHY-SAP 250 kb/s (Basic Mode) IFS

54. Mar. 2005 CWC/AETHERWIRE/CEA-LETI/STM/MERL doc.: IEEE 802. 15-05-xxxx-00-004a Slide 54 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

55. Mar. 2005 CWC/AETHERWIRE/CEA-LETI/STM/MERL doc.: IEEE 802. 15-05-xxxx-00-004a Slide 55 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  s 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

56. Mar. 2005 CWC/AETHERWIRE/CEA-LETI/STM/MERL doc.: IEEE 802. 15-05-xxxx-00-004a Slide 56 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

57. Mar. 2005 CWC/AETHERWIRE/CEA-LETI/STM/MERL doc.: IEEE 802. 15-05-xxxx-00-004a Slide 57 Ranging Motivation : – Benefit from high time resolution (thanks to signal bandwidth): Theoretically: 2GHz provides less than 20cm resolution Practically: Impairments, low cost/complexity devices should support ~50cm 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)

58. Mar. 2005 CWC/AETHERWIRE/CEA-LETI/STM/MERL doc.: IEEE 802. 15-05-xxxx-00-004a Slide 58 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., 4ns-20ns) 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., 1ns –> 4ns) or – Coherent search with a template correlation Energy Analyzer Integrator outputs Leading Edge Search Refinement Performed within the selected uncertainty region Detects the coarse “uncertainty region” Range info T RB : the length of uncertainty region

59. Mar. 2005 CWC/AETHERWIRE/CEA-LETI/STM/MERL doc.: IEEE 802. 15-05-xxxx-00-004a Slide 59 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. Actual TOA MES based TOA Estimate Strongest Path, energy block Contains leading edge Threshold based TOA Estimate Threshold Searchback window MES-SB based TOA Estimate MES: Maximum Energy Search TC: Threshold comparison SB: Search Back 0 1 2 N

60. Mar. 2005 CWC/AETHERWIRE/CEA-LETI/STM/MERL doc.: IEEE 802. 15-05-xxxx-00-004a Slide 60 ENERGY Spread in CM1 PDF of TOA estimation errors are illustrated for MES at various E b N 0 – CM1, integration interval 4ns, Tf=200ns (results will be updated for Tf=240ns)

61. Mar. 2005 CWC/AETHERWIRE/CEA-LETI/STM/MERL doc.: IEEE 802. 15-05-xxxx-00-004a Slide 61 Ranging Simulation Settings Notations and TermsDefinitionValue in Simulations TfTf Pulse repetition interval, frame200ns NbNb Number of blocks within a T f 50 NcNc Number of refinement intervals within a T f 400 TH{}Time hopping sequence in chips{h1,...., h5} POL{}Polarity codes{p1,..., p5} N1N1 Number of frames in the 1st-step50 N2N2 Number of frames in the refinement30 BWBandwidth2GHz CNumber of correlators (refinement stage)10 Note: Results are to be provided when T f is set to 240ns.

62. Mar. 2005 CWC/AETHERWIRE/CEA-LETI/STM/MERL doc.: IEEE 802. 15-05-xxxx-00-004a Slide 62 Ranging Results IEEE 802.15.4a CM1-Residential LOS Round Trip ranging error (with no drift compensation) – ~16cm (0.088ms), no clock drift – ~17.1cm (1ppm) – ~20.1cm (4ppm) – ~26cm (10ppm) – ~56cm (40ppm) True Distance (m)One-way ranging error (confidence level) 25 m 8 cm ( 97 %) 30 m 8 cm (~ 90 %)

63. Mar. 2005 CWC/AETHERWIRE/CEA-LETI/STM/MERL doc.: IEEE 802. 15-05-xxxx-00-004a Slide 63 Two Way Ranging (TWR) Main Limitations / Impact of Clock Drift on Perceived Time Range estimation is affected by : Relative clock drift between A and B Prescribed response delay Clock accuracy in A and B Channel response (weak direct path) Is the frequency offset relative to the nominal ideal frequency Simple immediate TWR made unusable with reasonnable crystal accuracies. Solution is : Performing fine drift estimation/compensation Benefiting from cooperative transactions (estimated clock ratios …) 250 kbps, 38 bytes PPDU 500 kbps, 9 bytes PPDU  f/f \ Treply (max error) 1408  s1226  s336  s154  s 4 ppm1.69 m1.47 m0.40 m0.18 m 25 ppm10.56 m9.19 m2.52 m1.15 m 40 ppm16.9 m14.7 m4.0 m1.8 m Example using Imm-ACK SIFS of 15.4 and 15.3 of respectively 192us and 10 us and PPDU size of respectively 38 and 9 bytes

64. Mar. 2005 CWC/AETHERWIRE/CEA-LETI/STM/MERL doc.: IEEE 802. 15-05-xxxx-00-004a Slide 64 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

65. Mar. 2005 CWC/AETHERWIRE/CEA-LETI/STM/MERL doc.: IEEE 802. 15-05-xxxx-00-004a Slide 65 Antenna Feasibility Capacitive Dipole and Various Bowtie Antennas Bowtie antenna 55 mm 40 mm

66. Mar. 2005 CWC/AETHERWIRE/CEA-LETI/STM/MERL doc.: IEEE 802. 15-05-xxxx-00-004a Slide 66 “Proof-of-Concept” (1) Non-coherent Transceiver 5 Mbps BPPM 350 ps pulse train with long scrambling code Non-coherent, Energy Collection Receiver

67. Mar. 2005 CWC/AETHERWIRE/CEA-LETI/STM/MERL doc.: IEEE 802. 15-05-xxxx-00-004a Slide 67 “Proof-of-Concept” (2) Non-coherent Transceiver UWB Transmitter 400 μm x 400 μm 0.35 μm CMOS UWB Transceiver Test architecture <10 mm 2 0.35 μm SiGe Bi-CMOS UWB-IR BPPM Non-Coherent Transceiver Implementation

68. Mar. 2005 CWC/AETHERWIRE/CEA-LETI/STM/MERL doc.: IEEE 802. 15-05-xxxx-00-004a Slide 68 “Proof-of-Concept” (3): Transmitter - Lower Band UWB Transmitter chip for generating impulse doublets Delay Buffers N-C N-Channel Drivers P-Channel Drivers

69. Mar. 2005 CWC/AETHERWIRE/CEA-LETI/STM/MERL doc.: IEEE 802. 15-05-xxxx-00-004a Slide 69 “Proof-of-Concept” (4): Receiver - Lower Band Coherent UWB Receiver with multiple time integrating correlators 32 Time-Integrating Correlators PLL Loop Filter VGC Amp Code Sequence Generators LF RTC DACs “Rails” for testing analog circuits DACs High-Frequency Real Time Clock

70. Mar. 2005 CWC/AETHERWIRE/CEA-LETI/STM/MERL doc.: IEEE 802. 15-05-xxxx-00-004a Slide 70 “Proof-of-Concept” (5) High Speed Coherent Circuit Elements 3-5 GHz LNA Chip and layout 20 GHz digitizer for UWB 20 GHz DLL for UWB RF front end chips in CMOS 0.13  m, 1.2V

71. Mar. 2005 CWC/AETHERWIRE/CEA-LETI/STM/MERL doc.: IEEE 802. 15-05-xxxx-00-004a Slide 71 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

72. Mar. 2005 CWC/AETHERWIRE/CEA-LETI/STM/MERL doc.: IEEE 802. 15-05-xxxx-00-004a Slide 72 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)

73. Mar. 2005 CWC/AETHERWIRE/CEA-LETI/STM/MERL doc.: IEEE 802. 15-05-xxxx-00-004a Slide 73 Backup Slides

74. Mar. 2005 CWC/AETHERWIRE/CEA-LETI/STM/MERL doc.: IEEE 802. 15-05-xxxx-00-004a Slide 74 BER Performance in AWGN Channel MRC Solution (coherent) Differential Solution Energy Collection solution in OOK Transmitted Reference (one pulse) -3 dB : the “reference” is not in the same PRP ! PER = 1% with 32 bytes PSDU  acceptable BER 4x10 -5 with no channel coding

75. Mar. 2005 CWC/AETHERWIRE/CEA-LETI/STM/MERL doc.: IEEE 802. 15-05-xxxx-00-004a Slide 75 BER Performance in AWGN Channel

76. Mar. 2005 CWC/AETHERWIRE/CEA-LETI/STM/MERL doc.: IEEE 802. 15-05-xxxx-00-004a Slide 76 Antenna Practicality Bandwidth: 3 GHz-10 GHz Form factor Omni-directional y x z 7 mm ground plane Ø 80 mm antenna hat Ø 24 mm  

77. Mar. 2005 CWC/AETHERWIRE/CEA-LETI/STM/MERL doc.: IEEE 802. 15-05-xxxx-00-004a Slide 77 Mobile (x m,y m ) Anchor 1 (x A1,y A1 ) Anchor 2 (x A2,y A2 ) Anchor 3 (x A3,y A3 ) Positioning from TDOA 3 anchors with known positions (at least) are required to find a 2D-position from a couple of TDOAs Measurements Estimated Position Specific Positioning Algorithms

78. Mar. 2005 CWC/AETHERWIRE/CEA-LETI/STM/MERL doc.: IEEE 802. 15-05-xxxx-00-004a Slide 78 TR BPPM Scheme Comparison

79. Mar. 2005 CWC/AETHERWIRE/CEA-LETI/STM/MERL doc.: IEEE 802. 15-05-xxxx-00-004a Slide 79 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

80. Mar. 2005 CWC/AETHERWIRE/CEA-LETI/STM/MERL doc.: IEEE 802. 15-05-xxxx-00-004a Slide 80 Pulse repetition structures TR BPPM with doublets (Scheme 1)

81. Mar. 2005 CWC/AETHERWIRE/CEA-LETI/STM/MERL doc.: IEEE 802. 15-05-xxxx-00-004a Slide 81 Pulse repetition structures TR BPPM single reference (Scheme 2)

82. Mar. 2005 CWC/AETHERWIRE/CEA-LETI/STM/MERL doc.: IEEE 802. 15-05-xxxx-00-004a Slide 82 Pulse repetition structures Auto Correlation BPPM with doublets (Scheme 3)

83. Mar. 2005 CWC/AETHERWIRE/CEA-LETI/STM/MERL doc.: IEEE 802. 15-05-xxxx-00-004a Slide 83 Pulse repetition structures Auto Correlation BPPM single reference (Scheme 4)

84. Mar. 2005 CWC/AETHERWIRE/CEA-LETI/STM/MERL doc.: IEEE 802. 15-05-xxxx-00-004a Slide 84 Pulse repetition structures Auto Correlation BPPM alternate ( Scheme 5)

85. Mar. 2005 CWC/AETHERWIRE/CEA-LETI/STM/MERL doc.: IEEE 802. 15-05-xxxx-00-004a Slide 85 Parameters PPI slot - slot inside each TH chip containing a burst of pulses including reference pulses (ref. slides from Laurent / CEA) N p represents the number of pulses in each PPI slot The energy E per PPI slot is kept constant The pulse energy E p = E/N p TW represent the time-bandwidth product

86. Mar. 2005 CWC/AETHERWIRE/CEA-LETI/STM/MERL doc.: IEEE 802. 15-05-xxxx-00-004a Slide 86 E p /N 0 degradation versus number of pulses per pulse train

87. Mar. 2005 CWC/AETHERWIRE/CEA-LETI/STM/MERL doc.: IEEE 802. 15-05-xxxx-00-004a Slide 87 E p /N 0 degradation versus Time/Bandwidth product

88. Mar. 2005 CWC/AETHERWIRE/CEA-LETI/STM/MERL doc.: IEEE 802. 15-05-xxxx-00-004a Slide 88 E p /N 0 degradation versus number of pulses per pulse train

89. Mar. 2005 CWC/AETHERWIRE/CEA-LETI/STM/MERL doc.: IEEE 802. 15-05-xxxx-00-004a Slide 89 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 noise- cross-noise-cross-noise... Products”. Seems to outperform other schemes with simple analysis Also more readily implementable since fixed delay line can be used.

90. Mar. 2005 CWC/AETHERWIRE/CEA-LETI/STM/MERL doc.: IEEE 802. 15-05-xxxx-00-004a Slide 90 Channel / Delay Estimation Coherent Approach

91. Mar. 2005 CWC/AETHERWIRE/CEA-LETI/STM/MERL doc.: IEEE 802. 15-05-xxxx-00-004a Slide 91 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

92. Mar. 2005 CWC/AETHERWIRE/CEA-LETI/STM/MERL doc.: IEEE 802. 15-05-xxxx-00-004a Slide 92 Optimal Energy-Threshold Analysis (CM-1) Optimal normalized threshold (normalized with respect to the difference between the maximum and minimum energy blocks) changes with E b /N 0 and block size. Smaller thresholds are required in general at high E b /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) E b /N 0 : { 8 --- 26dB}