Download
slide1 n.
Skip this Video
Loading SlideShow in 5 Seconds..
Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs) PowerPoint Presentation
Download Presentation
Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs)

Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs)

66 Views Download Presentation
Download Presentation

Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs)

- - - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

  1. Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs) Submission Title: TG4a UWB-PHY overview (to be updated). Date Submitted: November 1, 2005 Source: Gian Mario Maggio (STMicroelectronics) Contact: Gian Mario Maggio Voice: +41-22-929-6917, E-Mail: gian-mario.maggio@st.com Abstract: Review of the 802.15.4a UWB-PHY. Purpose: To provide a summary of the current status of the 802.15.4a UWB-PHY and an outlook of the future TG4a work for this portion of 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. Gian Mario Maggio (ST)

  2. 802.15.4a UWB-PHY (http://www.ieee802.org/15/pub/TG4a.html) For Minutes Purposes Only–To be Updated! Gian Mario Maggio STMicroelectronics November 1st, 2005 Gian Mario Maggio (ST)

  3. Outline • 802.15.4a introduction • UWB-PHY • Band-plan • Pulse compression • Modulation • FEC options • To Do Gian Mario Maggio (ST)

  4. 802.15.4a: Introduction • The IEEE 802.15 Low Rate Alternative PHY Task Group (TG4a) for Wireless Personal Area Networks (WPANs) has defined a project for an amendment to 802.15.4 for an alternative PHY. • The principle interest is in providing communications and high precision ranging/location capability (1 meter accuracy and better), high aggregate throughput, and ultra low power; as well as adding scalability to data rates, longer range, and lower power consumption and cost. • These additional capabilities over the existing 802.15.4 standard are expected to enable significant new applications and market opportunities. Gian Mario Maggio (ST)

  5. 802.15.4a: Short History • 802.15.4a became an official Task Group in March 2004; with its committee work tracing back to November 2002. • The committee is actively drafting an alternate PHY specification for the applications identified • In March 2005, the baseline specification was selected (without enacting down-selection procedures)  the baseline with 100% approval. • The baseline is two optional PHYs consisting of: • UWB Impulse Radio (operating in unlicensed UWB spectrum) • Chirp Spread Spectrum (operating in unlicensed 2.4GHz spectrum). • The UWB Impulse Radio will be able to deliver communications and high precision ranging. Gian Mario Maggio (ST)

  6. 802.15.4a: Schedule Gian Mario Maggio (ST)

  7. TG4a Working Groups UWB-PHY (P. Rouzet – ST) CSS-PHY (J. Lampe – Nanotron) Sub-GHz (P. Houghton – AetherWire) Ranging (V. Brethour – Time Domain) Channel modeling (A. Molisch – MERL) MAC (J. Bain – Fearn Consulting ) Gian Mario Maggio (ST)

  8. UWB-PHY Sub-groups Bandplan TSE: Saeid Safavi Pulse modulation TSE: Phil Orlik Pulse compression TSE: Ismail Lakkis Simulation TSE: Matt Wellborn Sub-GHz UWB-PHY TSE: Mark Jamtgaard Liaison to IEEE 802.19 Patricia Martigne Gian Mario Maggio (ST)

  9. UWB-PHY: Introduction • Impulse-radio based (pulse-shape independent) • Support for different receiver architectures (coherent/non-coherent) • Flexible modulation format • Support for multiple rates • Support for SOP Gian Mario Maggio (ST)

  10. Pulse Shaping a) Gaussian b) Raised cosine c) Chaotic d) Chirp … Optional: • Variable pulse shapes with SSA (Soft Spectrum Adaptation) • Linear pulse combination Gian Mario Maggio (ST)

  11. Modulation Format(s) • Simple, scalable modulation format • One mandatory mode plus one or more optional modulation modes • Modulation compatible with multiple coherent/non-coherent receiver schemes  Flexibility for system designer • Time hopping (TH) to achieve multiple access Gian Mario Maggio (ST)

  12. Definitions Gian Mario Maggio (ST)

  13. PRF Definition: Example Pulse Repetition Interval 1 2 3 4 5 6 7 8 N-1 N ………………………… Non-inverted pulses are blue, Inverted pulses are green. Pulse Width, Tc ~ 4ns @ 500MHz BW ………………………................. …………… Quiet time Active time Symbol Interval Gian Mario Maggio (ST)

  14. Minimum PRF Requirements Gian Mario Maggio (ST)

  15. Band-Plan Gian Mario Maggio (ST)

  16. Bandplan: Status • The list of criteria for Bandplan Selection has been approved (doc 05/0355r03 with 11 criteria), after discussion and approval of a couple of modifications • The Bandplan approved at Cairn’s has been confirmed after voting (selection among a list of proposed bandplans presented in doc 05/0389r02, 78 % in favor ). Gian Mario Maggio (ST)

  17. Frequency Plan Gian Mario Maggio (ST)

  18. Frequency Plan Band No. 4 111 MHz 207 MHz 1 2 3 3 4 5 GHz 3.25 3.5 3.75 4.25 4.5 4.75 Gian Mario Maggio (ST)

  19. Above 6GHz Frequency Plan (proposal) Band No. 8 5 6 7 6 8 10 GHz 6.5 7 7.5 8.5 9 9.5 Gian Mario Maggio (ST)

  20. Pulse Compression(Preamble) Gian Mario Maggio (ST)

  21. Pulse Compression: Status • The list of criteria for Pulse Compression has been approved by unanimous consent (doc 05/0379r02 Pulse Compression Criteria for UWB PHY. ) • A motion has been unanimously approved to adopt the format of preamble S field as defined in document 0456 01 • It is confirmed that this S preamble format is applicable for communication and ranging, in all 3 modes (coherent, diff. coherent, non coherent) • New work will start to define the data symbol format: • Place of the start delimiter • Order of the +, - symbols in the code sequence • Usage of the proposed sequence for ranging messages (variable length preamble) • Spectral lines in long sequences? Gian Mario Maggio (ST)

  22. -S 0 -S 0 S S S S -S 0 -S 0 S S S S Preamble Structure Preamble Header Payload • SYNC : Synchronization Field • SFD : Start Frame Delimiter Field • CE : Channel Estimation Field • NOTE : Only the content of S field is specified (not the polarity or placement within the preamble) • Preamble length : 50 us, or 500 us or 4 ms SYNC/CE SYNC SFD S S S S S S or -S -S -S S S S Gian Mario Maggio (ST)

  23. The PBTSs (Length 127) Gian Mario Maggio (ST)

  24. The PBTSs (Length 31) Gian Mario Maggio (ST)

  25. Autocorrelation & Crosscorrelation (L = 31) Gian Mario Maggio (ST)

  26. Preamble length is an integer multiple of the S field • MandatoryLow PRF Mode • Adaptive Peak PRF (mechanism TBD) : 30.875 MHz & 7.71875MHz • All devices should support both PRFs • Codes : the set of 6 PBTSs (1) of length 31 (within a cyclic shift) • Optional High PRF • Peak PRF : 247 MHz • Codes : the set of 5 PBTSs of length 127 (within a cyclic shift) (1) Perfect Balanced Ternary Sequences Gian Mario Maggio (ST)

  27. Modulation Gian Mario Maggio (ST)

  28. Pulse Modulation: Status • The list of criteria for Modulation has been presented, 1 technical modification has been discussed and accepted, then the list has been approved by unanimous consent (doc 05/0424r1 ) • New presentations of possible modulations have been shown by their authors (3 presentations): 5/0231r7, 05/0428r0 , 05/0429r00 • Remain to be determined: • PRF and symbol duration • FEC options Gian Mario Maggio (ST)

  29. Proposed Selection Criteria (in decreasing priority order) • PER (packet error rate) performance @1Mb/s with 15.4a channel models, rate ½ convolutional code (constraint length up to 5; more needs justification): 1.a) Coherent receiver 1.b) Diff. coherent receiver 1.c) Non-coherent receiver • SOP isolation (at least 2 SOP/band; up to 6 SOP) • Peak-to-peak voltage shall be specified, 1Vpp or Less is preferable • Spectrum: SPAR (spectral peak-to-average ratio) • Receiver flexibility: Support for coherent, diff. coherent and non-coherent RX • Scalability: Trade-off performance vs. complexity • Resilience to NBI (narrow-band interference) Gian Mario Maggio (ST)

  30. Simulation Guidelines • PER (packet error rate) performance @1Mb/s vs. Eb/N0 • AWGN • Performance Coherent, Diff. Coherent, Non-coherent receive • 4a channel models • Order of importance: CM1, CM8, then others • Show PER performance without receiver enhancements (e.g. a single rake finger for coherent receivers) • Show PER performance with proposal's enhancements • SOP isolation • Desired signal set at 6dB above sensitivity (Eb/N0 where 1% PER was achieved in the channel model.) • Vary SINR compute PER. Multiple interferer scenarios should use equal power. • Spectrum: SPAR (spectral peak-to-average ratio) • State/show what back-off will be required. Gian Mario Maggio (ST)

  31. Modulation: PRF 62 & 494 MHz Gian Mario Maggio (ST)

  32. Modulation: PRF 31 & 247 MHz Gian Mario Maggio (ST)

  33. S = +--+-++- = S 1 chip ~ 2 ns burst duration = TB = 8 chips ~ 16 ns symbol duration ~ 1.0us = 512 chips = 64 TB (FEC 5 option) Modulation: Bursts and Peak PRF • Proposed peak PRF of 494 MHz, with S code of length 8 (TBC) • S code duration = 8 / peak PRF ~ 16 ns • Chip duration is 1/peak PRF Gian Mario Maggio (ST)

  34. 47 47 47 47 48 48 48 48 0 0 0 0 1 1 1 1 31 31 31 31 32 32 32 32 33 33 33 33 63 63 63 63 15 15 15 15 16 16 16 16 burst PPI = 32 bursts = 512ns symbol duration ~ 1.0us = 64 TB (FEC 5 option) Modulation PPM bit (seen by coherent and non coherent receiver) BPSK bit (seen by coherent receiver only) S -S S -S Gian Mario Maggio (ST)

  35. S S S S 47 47 47 47 48 48 48 48 0 0 0 0 1 1 1 1 31 31 31 31 32 32 32 32 33 33 33 33 63 63 63 63 15 15 15 15 16 16 16 16 -S -S -S -S S S S -S -S -S Scrambling possible positions obtained through scrambling Guard time for channel delay spread (260ns) S -S S -S • Remark: S value is also changed at each symbol Gian Mario Maggio (ST)

  36. Modulation Symbol Structure • Assumptions • Bit rate after decoding is 1Mbps • # of chips/symbol = 256 • Chip rate 494 Mcps (most of these are zeros; only 8 pulses/symbol) • Chip duration ≈ 2 ns (2.024291 ns) • Symbol duration 518.2186 ns • Average PRF = 8/518.2186 = 15.4375 MHz • Peak PRF • Determined by the “packing” of pulses 2. 024291ns - - - - + + + + 0 0 0 0 0 0 0 0 0 0 0 0 0 0 … 0 2. 024291ns - - - - + 0 + 0 0 0 + 0 0 + 0 0 0 0 0 0 0 0 … 0 Gian Mario Maggio (ST)

  37. -S Modulation: Peak PRF 247 MHz • Chip duration ≈ 2 ns (2.024291 ns) • Burst sequence of 8 pulses over 16 chips (alternating zeros) • Burst length ≈ 32.4 ns • BPSK + 2PPM • 1 bit modulates burst polarity1 bit modulates position. • 8 possible scrambling positions for each burst 518.2186 ns 32.4 ns 10 S 0 00 -S 0 11 S 1 01 1 1 2 3 4 5 6 7 8 S = +0+-0-+0-0+0-0+ Gian Mario Maggio (ST)

  38. Modulation: Peak PRF 494 MHz • Chip duration ≈ 2 ns (2.024291 ns) • Burst sequence of 8 pulses over 8 chips (NO zero insertion) • Burst length ≈ 16.2 ns • BPSK + 2PPM • 1 bit modulates burst polarity1 bit modulates position. • 16 possible scrambling positions for each burst 518.2186 ns 16.2ns 10 S 0 00 -S 0 11 S 1 01 -S 1 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 S = +0+0-0-+0-0+0-0+ (typo: no zeros!) Gian Mario Maggio (ST)

  39. Transmitter Architecture Gian Mario Maggio (ST)

  40. Receiver Structure Gian Mario Maggio (ST)

  41. Modulation-Extra Gian Mario Maggio (ST)

  42. S S S S S S S S 23 23 23 23 23 23 23 23 24 24 24 24 24 24 24 24 39 39 39 39 39 39 39 39 40 40 40 40 40 40 40 40 47 47 47 47 47 47 47 47 48 48 48 48 48 48 48 48 56 56 56 56 56 56 56 56 57 57 57 57 57 57 57 57 0 0 0 0 0 0 0 0 31 31 31 31 31 31 31 31 32 32 32 32 32 32 32 32 63 63 63 63 63 63 63 63 7 7 7 7 7 7 7 7 8 8 8 8 8 8 8 8 15 15 15 15 15 15 15 15 16 16 16 16 16 16 16 16 -S -S -S -S -S -S -S -S Proposal 6 : 4-PPM + BPSK Guard time for channel delay spread (130ns) Gian Mario Maggio (ST)

  43. S S S S S S S S 23 23 23 23 23 23 23 23 24 24 24 24 24 24 24 24 39 39 39 39 39 39 39 39 40 40 40 40 40 40 40 40 47 47 47 47 47 47 47 47 48 48 48 48 48 48 48 48 56 56 56 56 56 56 56 56 57 57 57 57 57 57 57 57 0 0 0 0 0 0 0 0 31 31 31 31 31 31 31 31 32 32 32 32 32 32 32 32 63 63 63 63 63 63 63 63 7 7 7 7 7 7 7 7 8 8 8 8 8 8 8 8 15 15 15 15 15 15 15 15 16 16 16 16 16 16 16 16 -S -S -S -S -S -S -S -S Proposal 6 : 4-PPM + BPSK PPM bits (seen by both receivers) BPSK bit (seen by coherent receiver only) Gian Mario Maggio (ST)

  44. -S -S -S S S S -S S S -S -S -S S S S -S S -S -S S S -S S -S S -S S -S S -S S -S 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 11 11 11 11 11 11 11 11 11 11 11 11 11 11 11 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 13 13 13 13 13 13 13 13 13 13 13 13 13 13 13 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 17 17 17 17 17 17 17 17 17 17 17 17 17 17 17 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 21 21 21 21 21 21 21 21 21 21 21 21 21 21 21 22 22 22 22 22 22 22 22 22 22 22 22 22 22 22 23 23 23 23 23 23 23 23 23 23 23 23 23 23 23 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 26 26 26 26 26 26 26 26 26 26 26 26 26 26 26 27 27 27 27 27 27 27 27 27 27 27 27 27 27 27 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 29 29 29 29 29 29 29 29 29 29 29 29 29 29 29 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 31 31 31 31 31 31 31 31 31 31 31 31 31 31 31 Guard time (120 ns) Scrambling Range (120 ns) Modulation : 8-PPM + BPSK Gray coded Gian Mario Maggio (ST)

  45. FEC Options Gian Mario Maggio (ST)

  46. FEC Options Coherent Receiver: True Rate = ¼ Non Coherent Receiver: Equivalent to Rate = ½ (Rate ¼ with erasures) SOC code K= 3,4 or 5 R = 1/4 FEC 1 Coherent Receiver: True Rate = ¼ Non Coherent Receiver: Equivalent to Rate = ½ (Rate ¼ with erasures) Convolutional Encoder K= 3,4 or 5 R= 1/4 FEC 2 Systematic Convolutional Encoder K= 3,4 or 5 R = 1/2 Convolutional Encoder K=3, R= 1/2 Coherent Receiver: Concatenated code, Rate = ¼ Non Coherent Receiver: Convolutional code, Rate = ½ FEC 3 Systematic Convolutional Encoder K= 3,4 or 5 R = 1/2 BCH or RS GF(28): RS(40,32) GF(26): RS(53,43) Coherent Receiver: Concatenated code Rate = 0.4 Non Coherent Receiver: RS code, Rate = 0.8 FEC 4 Systematic Convolutional Encoder K= 3,4 or 5 R= 1/2 Coherent Receiver: Convolutionalcode Rate = ½ Non Coherent Receiver: Uncoded FEC 5 Convolutional Encoder K= 3,4 or 5 R= 1/3 Coherent Receiver: Convolutionalcode Rate = 1/3 Non Coherent Receiver: Convolutionalcode Rate = 1/2 FEC 6 Gian Mario Maggio (ST)

  47. Viterbi 1/3 Convolutional 1/3 Viterbi 1/2 Example: FEC 6 Common Rb at PHY SAP + Coder + Modulation Mapping Non Coherent Receiver (only 4-PPM) Non Coherent Receiver (4-PPM + Polarity) Gian Mario Maggio (ST)

  48. Example: FEC 6  Perfect compatibility between Tx and coherent and non-coherent Rx Gian Mario Maggio (ST)

  49. Summary of Rates Options we intend to simulate and compare Gian Mario Maggio (ST)

  50. Simulation Results Gian Mario Maggio (ST)