Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs) Submission Title: DBO-CSS PHY Presentati - PowerPoint PPT Presentation

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Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs) Submission Title: DBO-CSS PHY Presentati

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  1. Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs) Submission Title:DBO-CSS PHY Presentation for 802.15.4a Date Submitted: March 07, 2005 Source: [(1) John Lampe, et al, (2) Kyung-Kuk Lee, et al] Company: [(1) Nanotron Technologies, (2) Orthotron Co., Ltd.] Address: [(1) Alt-Moabit 61, 10555 Berlin, Germany, (2) 709 Kranz Techono, 5442-1 Sangdaewon-dong, Jungwon-gu, Sungnam-si, Kyungki-do, Korea 462-120] Voice: [(1) +49 30 399 954 135, (2) 82-31-777-8198 ], E-Mail: [(1)j.lampe@nanotron.com, (2) kyunglee@orthotron.com] Re: This is in response to the TG4a Call for Proposals, 04/0380r2 Abstract: The Nanotron - Orthotron DBO-CSS is described and the detailed response to the Selection Criteria document is provided Purpose: Submitted as the candidate proposal for TG4a Alt-PHY 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. Lampe, Hach, Menzer, Nanotron; Lee, Orthotron

  2. Differentially Bi-OrthogonalChirp-Spread-SpectrumPHY Proposal for 802.15.4a by John Lampe, Rainer Hach, and Lars Menzer Nanotron Technologies GmbH, Germany j.lampe@nanotron.com Kyung-Kuk Lee / Jong-Wha Chong Orthotron Co., Ltd. / Hanyang Univ., Korea kyunglee@orthotron.com Lampe, Hach, Menzer, Nanotron; Lee, Orthotron

  3. Contents • DBO-CSS System Overview • Selection Criteria Document Topics • PAR and 5C Requirement Checklist • Summary Lampe, Hach, Menzer, Nanotron; Lee, Orthotron

  4. DBO-CSS System Overview • Chirp Property • Concept of Sub-Chirps • Block-diagram ♣ DBO-CSK: Differentially Bi-Orthogonal Chirp-Spread-Spectrum Lampe, Hach, Menzer, Nanotron; Lee, Orthotron

  5. t Correlation Property of Chirp Signal 1 0.8 1 0.6 0.8 0.6 Amplitude 0.4 0.4 0.2 0 -0.2 0.2 -0.4 -0.6 -0.8 0 -1 -200 -150 -100 -50 0 50 100 150 200 DBO-CSS System Overview Chirp Properties Linear Chirp: Rectangular Window t Linear Chirp: Raised-Cosine Window Lampe, Hach, Menzer, Nanotron; Lee, Orthotron

  6. Freq. - Time I II III IV t t t t DBO-CSS System Overview Concept of Sub-Chirps Spectrum 0 Fbw = 7.0 MHz rolloff = 0.25; Fdiff = 6.3 MHz; Tc = 4.8usec -10 -20 -30 -40 -50 -20 -10 fc 10 20 (MHz) Same Spectrum with IEEE802.11a / 11b Lampe, Hach, Menzer, Nanotron; Lee, Orthotron

  7. Freq. - Time I II III IV t t t t DBO-CSS System Overview Concept of Sub-Chirps Waveform Lampe, Hach, Menzer, Nanotron; Lee, Orthotron

  8. DBO-CSS System Overview Block-diagram: DBO-CSSTransmitter Digital MOD Low-Pass Filter I/Q Modulator LP I fT = f ± 10 MHz LP Q LO fc Lampe, Hach, Menzer, Nanotron; Lee, Orthotron

  9. DBO-CSS System Overview Block-diagram: DBO-CSSReceiver 3 2 Low-Pass Filter I/Q Demodulator DDDL 1 Up LP ADC I Down Digital DEMOD LP ADC Q LO fR = fLO ± 10 MHz RSSI DBO-CSS pulse 1 fc Correlation pulse 2 Trigger signal with adaptive threshold 3 Lampe, Hach, Menzer, Nanotron; Lee, Orthotron

  10. Differentially Bi-Orthogonal Symbol Binary Data …010011100110001101… Bi-Orthogonal Symbol Binary Symbol Symbol Mapper Scram -bler FEC r=1, 1/2 S/P 4 1 3 4 P/S 8-ary DBO-CSK CSK Gen. DBO-CSS System Overview Block-diagram: 8-ary DBO-CSSModulator Lampe, Hach, Menzer, Nanotron; Lee, Orthotron

  11. Selection Criteria Document Topic • Band in Use • Signal Robustness interference mitigation techniques. Interference Susceptibility Coexistence • Technical Feasibility Manufacturability Time to Market Regulatory Impact Backward Compatibility • Scalability • Mobility • MAC Protocol Supplement • PHY Layer Criteria Unit Manufacturing Cost/Complexity (UMC) Size and Form Factor Payload Bit Rate and Data Throughput • Simultaneously Operating Piconets • Signal Acquisition • Clear Channel Assessment • System Performance Error rate Receiver sensitivity • Ranging • Link Budget • Power Management Modes • Power Consumption • Antenna Practicality Lampe, Hach, Menzer, Nanotron; Lee, Orthotron

  12. Spectrum 0 Fbw = 7.0 MHz rolloff = 0.25; Fdiff = 6.3 MHz; Tc = 4.8usec -10 -20 -30 -40 -50 -20 -10 fc 10 20 (MHz) Same Spectrum with IEEE802.11b Selection Criteria Document Topic Band in Use: • 2.4GHz ISM Band with 802.11b channel scheme • 20MHz Bandwidth: Consists of 4 sub-chirp signals per Carrier Lampe, Hach, Menzer, Nanotron; Lee, Orthotron

  13. Selection Criteria Document Topic Signal Robustness: • Co-existence / Interference Mitigation Technique - Orthogonal / Quasi-Orthogonal Signal Set - High Spectral Processing Gain: Chirp - Near-Far Problem: FDM Channels (7ch @2.4GHz) • Interference Susceptibility - Low Cross-Correlation property with Existing Signal • Robustness: - Heavy Multi-path Environment - SOP • Low Sensitivity for Component Tolerance - Crystal : ± 40ppm • Mobility - Wide-band Chirp: Insensitive for Fading & Doppler Shift - Easily Maintaining Timing Sync. of Received Signal Lampe, Hach, Menzer, Nanotron; Lee, Orthotron

  14. Selection Criteria Document Topic Signal Robustness: Interference Mitigation Techniques • The proposed DBO-CSS PHY is designed to operate in a hostile environment • Multipath • Narrow and broadband intentional and unintentional interferers • Since a chirp transverses a relatively wide bandwidth it has an inherent immunity to narrow band interferers • Multipath is mitigated with the natural frequency diversity of the waveform • Broadband interferer effects are reduced by the receiver’s correlator • Forward Error Correction (FEC) can further reduce interference and multipath effects. • Three non-overlapping frequency channels in the 2.4 GHz ISM band • This channelization allows this proposal to coexist with other wireless systems such as 802.11 b, g and even Bluetooth (v1.2 has adaptive hopping) via DFS • DBO-CSS proposal utilizes CCA mechanisms of Energy Detection (ED) and Carrier Detection • These CCA mechanisms are similar to those used in IEEE 802.15.4-2003 • In addition to the low duty cycle for the applications served by this standard sufficient arguments were made to convince the IEEE 802 sponsor ballot community that coexistence was not an issue. Lampe, Hach, Menzer, Nanotron; Lee, Orthotron

  15. Selection Criteria Document Topic Signal Robustness: Interference Susceptibility Support for Interference Ingress • Example (without FEC): • Bandwidth B of the chirp = 20 MHz • Duration time T of the chirp = 4.8 µs • Center frequency of the chirp (ISM band) = 2.437 GHz • Processing gain, BT product of the chirp = 19.8 dB • Eb/N0 at detector input (BER=10E-4) = 12.5 dB • In-band carrier to interferer ratio (C/I @ BER=10-4)= 12.5 – 19.8 = -7.3 dB Lampe, Hach, Menzer, Nanotron; Lee, Orthotron

  16. Selection Criteria Document Topic Signal Robustness: Coexistence Low interference egress • IEEE 802.11b receiver • More than 30 dB of protection in an adjacent channel • Almost 60 dB in the alternate channel • These numbers are similar for the 802.11g receiver Lampe, Hach, Menzer, Nanotron; Lee, Orthotron

  17. Selection Criteria Document Topic Technical Feasibility: Manufacturability Lampe, Hach, Menzer, Nanotron; Lee, Orthotron

  18. Selection Criteria Document Topic Technical Feasibility: Time to Market • No regulatory hurdles • DBO-CSS based chips are available on the market • No research barriers – no unknown blocks • Normal design and product cycles will apply • Can be manufactured in all CMOS Lampe, Hach, Menzer, Nanotron; Lee, Orthotron

  19. Selection Criteria Document Topic Technical Feasibility: Regulatory Impact • Devices manufactured in compliance with the DBO-CSS proposal can be operated under existing regulations in all significant regions of the world - Including but not limited to North and South America, Europe, Japan, China, Korea, and most other areas - There are no known limitation to this proposal as to indoors or outdoors • The DBO-CSS proposal would adhere to the following worldwide regulations: - United States Part 15.247 or 15.249 - Canada DOC RSS-210 - Europe ETS 300-328 - Japan ARIB STD T-66 Lampe, Hach, Menzer, Nanotron; Lee, Orthotron

  20. Selection Criteria Document Topic Technical Feasibility: Backward Compatibility • Due to the similarities with DSSS it is possible to implement this proposal in a manner that will allow backward-compatibility with the 802.15.4 2.4 GHz standard. • The transmitter changes are relatively straightforward. • Changes to the receiver would include either dual correlators or a superset of DBO-CSS and DSSS correlators. • Optional methods for backward-compatibility could be left up to the implementer - mode switching - dynamic change (on-the-fly) technique • This backward-compatibility would be a significant advantage in the marketplace by allowing these devices to communicate with existing deployed 802.15.4 infrastructure and eliminating customer confusion. Lampe, Hach, Menzer, Nanotron; Lee, Orthotron

  21. Selection Criteria Document Topic Scalability: Data-rate • Mandatory rate = 1 Mb/s • Optional rates = 500 Kb/s, 250 Kb/s • Lower data rates achieved by using interleaved FEC • Lower chirp rates would yield better performance - longer range, less retries, etc. in an AWGN environment or a multipath limited environment • It should be noted that these data rates are only discussed here to show scalability, if these rates are to be included in the draft standard the group must revisit the PHY header such as the SFD. Lampe, Hach, Menzer, Nanotron; Lee, Orthotron

  22. Selection Criteria Document Topic Scalability: Frequency Bands • The proposer is confident thatthe DBO-CSSproposal would alsowork well in other frequency bands • Ex) Including the 5 GHz UNII / ISM bands Lampe, Hach, Menzer, Nanotron; Lee, Orthotron

  23. Selection Criteria Document Topic Scalability: Power Levels • For extremely long ranges the transmit power may be raised to each country’s regulatory limit, for example: • The US would allow 30 dBm of output power with up to a 6 dB gain antenna • The European ETS limits would specify 20 dBm of output power with a 0 dB gain antenna • Note that even though higher transmit power requires significantly higher current it doesn’t significantly degrade battery life since the transmitter has a much lower duty cycle than the receiver, typically 10% or less of the receive duty cycle. Lampe, Hach, Menzer, Nanotron; Lee, Orthotron

  24. Communication No system inherent restrictions are seen for this proposal The processing gain of chirp signals is extremely robust against frequency offsets such as those caused by the Doppler effect when there is a high relative speed vrel between two devices. The Doppler effect must also be considered when one device is mounted on a rotating machine, wheel, etc. The limits will be determined by other, general (implementation-dependent) processing modules (AGC, symbol synchronization, etc.). Ranging The ranging scheme proposed in this document relies on the exchange of two hardware acknowledged data packets One for each direction between two nodes The total time for single-shot (2 data, 2 Ack) ranging procedure between the two nodes is the time trangingwhich, depending on the implementation, might be impacted by the uC performance. During this time the change of distance should stay below the accuracy da required by the application. The worst case is: For da = 1m tranging= 2 ms this yields vrel << 1000 m/s Selection Criteria Document Topic Mobility Lampe, Hach, Menzer, Nanotron; Lee, Orthotron

  25. Selection Criteria Document Topic MAC Protocol Supplement • There are very minimal anticipated changes to the 15.4 MAC to support the proposed Alt-PHY. • Three channels are called for with this proposal and it is recommended that the mechanism of channel bands from the proposed methods of TG4b be used to support the new channels. • There will be an addition to the PHY-SAP primitive to include the choice of data rate to be used for the next packet. This is a new field. • Ranging calls for new PHY-PIB primitives are expected to be developed by the Ranging subcommittee. Lampe, Hach, Menzer, Nanotron; Lee, Orthotron

  26. Selection Criteria Document Topic PHY Layer Criteria: Manufacturing Cost/Complexity Lampe, Hach, Menzer, Nanotron; Lee, Orthotron

  27. Selection Criteria Document Topic PHY Layer Criteria: Manufacturing Cost/Complexity • Target process:RF-CMOS, 0.18 µm feature size Lampe, Hach, Menzer, Nanotron; Lee, Orthotron

  28. Selection Criteria Document Topic PHY Layer Criteria: Manufacturing Cost/Complexity • Target process:RF-CMOS, 0.13 µm feature size Lampe, Hach, Menzer, Nanotron; Lee, Orthotron

  29. Selection Criteria Document Topic PHY Layer Criteria: Size and Form Factor • The implementation of the DBO-CSS proposal will be much less than SD Memory at the onset • Following the form factors of Bluetooth and IEEE 802.15.4 / ZigBee • The implementation of this device into a single chip is relatively straightforward • As evidenced in the “Unit Manufacturing Complexity” slides Lampe, Hach, Menzer, Nanotron; Lee, Orthotron

  30. RF Base band Pattern Antenna (24mm X 14mm) Button Cell Battery Button Cell Battery Pattern Antenna (12mm X 9mm) RF + + Base band 5.1/5.7 GHz Selection Criteria Document Topic PHY Layer Criteria: Size and Form Factor SD Memory (32mm X 24 mm) SD Memory (32mm X 24 mm) 2.4 GHz • Ex) • Battery Capacity: 3V x 30mAh (324Joule) • Dimension: 10 x 2.5 (Dia. x Ht. mm) Lampe, Hach, Menzer, Nanotron; Lee, Orthotron

  31. Selection Criteria Document Topic PHY Layer Criteria: Bit Rate and Data Throughput Payload Bit-rate: • Data-rate: 1MHz / 500Kbps / 250Kbps per piconet • Aggregated Data-rate: Max. 4Mbps (4 X 1Mbps) per FDM Channel • FDM Channels: 7 CH. (2.4GHz) • Data Throughput: • Payload bit-rate 1Mbps / 500Kbps / 250Kbps : Throughput 446 Kbps / 293 Kbps/173.7 Kbps Payload: 32byte 5byte DATA Frame ACK Frame DATA Frame TLIFT TACK 114 / 156 / 240 μsec 330 / 588 / 1104 μsec 574 / 874 / 1474 μsec TACK + TLIFT = 130usec Lampe, Hach, Menzer, Nanotron; Lee, Orthotron

  32. Selection Criteria Document Topic PHY Layer Criteria: Bit Rate and Data Throughput Data Frame: Payload bit-rate : 1Mbps (r=1) / 500Kbps (r=1) / 250Kbps (r=1/2) 5Chirp 1Chirp 6Chirp 43chirps (1Mbps) / 86chirps (500Kbps) or 172chirps (250Kbps) Preamble Delimiter Length + Rate MPDU (8 + 1)bit (32X8 +2) bit 330 μsec (1Mbps) / 588 μsec (500Kbps) / 1104 μsec (250Kbps) ACK Frame: Payload bit-rate : 1Mbps(r=1) / 500Kbps (r=1)/ 250Kbps (r=1/2) 5Chirp 1Chirp 6Chirp 7chirps (1Mbps) / 14chirps (500Kbps) / 28chirps (250Kbps) Preamble Delimiter Length + Rate MPDU (8 + 1)bit (5X8 +2) bit 114 μsec (1Mbps) / 156 μsec (500Kbps) / 240 μsec (250Kbps) Lampe, Hach, Menzer, Nanotron; Lee, Orthotron

  33. Selection Criteria Document Topic PHY Layer Criteria: Bit Rate and Data Throughput • The SFD structure has different values for, and determines, the effective data rate for PHR and PSDU • The Preamble is 32 bits in duration (a bit time is 1 µs) • In this proposal, the PHR field is used to describe the length of the PSDU that may be up to 256 octets in length • In addition to the structure of each frame, the following shows the structure and values for frames including overhead not in the information carrying frame Lampe, Hach, Menzer, Nanotron; Lee, Orthotron

  34. 797 Kb/s 330 Kb/s 245 Kb/s 155 Kb/s 267 Kb/s plot 1 Mb/s plot Tack= 192 µs SIFS= 192 µs Selection Criteria Document Topic PHY Layer Criteria: Bit Rate and Data Throughput Lampe, Hach, Menzer, Nanotron; Lee, Orthotron

  35. Selection Criteria Document Topic Simultaneously Operating Piconets • Separating Piconets by frequency division • This DBO-CSS proposal includes a mechanism for FDMA by including the three frequency bands used by 802.11 b, g and also 802.15.3 • It is believed that the use of these bands will provide sufficient orthogonality • The proposed chirp signal has a rolloff factor of 0.25 which in conjunction with the space between the adjacent frequency bands allows filtering out of band emissions easily and inexpensively. Lampe, Hach, Menzer, Nanotron; Lee, Orthotron

  36. I II III IV Selection Criteria Document Topic Simultaneously Operating Piconets Correlation Power (For Preamble Detection) t CSKSignal : Quasi-Orthogonal Property Correlation Property between the piconet Does not need Synchronization inter-piconet Each of CSKSignal consists of 4 sub-chirp signals. Lampe, Hach, Menzer, Nanotron; Lee, Orthotron

  37. Selection Criteria Document Topic Simultaneously Operating Piconets Complex Amplitude (for Data Demod) I II III IV CSKSignal : Quasi-Orthogonal Property Correlation Property between piconet Each of CSKSignal consists of 4 sub-chirp signals. Lampe, Hach, Menzer, Nanotron; Lee, Orthotron

  38. Duration of 2 Symbols (12 usec) I II III IV 0.3usec 2.1usec d11 d12 0.6usec 1.8usec d21 d22 0.9usec 1.5usec d31 d32 1.2usec 1.2usec d41 d42 4.8 usec Selection Criteria Document Topic Simultaneously Operating Piconets • SOP: Assigning Different Time-Gap between the Chirp-Shift-Keying Signal • Minimize ISI for CM8 NLOS: Assign the Time-Gap between symbol more then 200nsec Lampe, Hach, Menzer, Nanotron; Lee, Orthotron

  39. Selection Criteria Document Topic Simultaneously Operating Piconets Interference Testedby Packet (32 bytes Random Data) I II III IV Differential Detection Property between piconet Each of CSKSignal consists of 4 sub-chirp signals. Lampe, Hach, Menzer, Nanotron; Lee, Orthotron

  40. System Performance in 1 interf. piconet System performance with 2 interf. piconet 0 0 10 10 AWGN AWGN CM8 CM8 CM1 CM1 CM5 CM5 -1 -1 10 10 -2 -2 10 PER 10 PER -3 -3 10 10 -4 -4 10 10 0 0.5 1 1.5 2 2.5 3 0.5 1 1.5 2 2.5 3 3.5 Dint/Dref Dint/Dref System performance with 3 interf. piconet 0 10 AWGN CM8 CM1 CM5 -1 10 -2 10 PER -3 10 -4 10 1 1.5 2 2.5 3 3.5 4 Dint/Dref Selection Criteria Document Topic Simultaneously Operating Piconets Available SOPs • 2.4GHz: 4[piconets/FDM Ch.] x 7[FDM Ch.] = 28 SOPs • 5.2GHz: 4[piconets/FDM Ch.] x 8[FDM Ch.] = 32 SOPs • 5.7GHz: 4[piconets/FDM Ch.] x 6[FDM Ch.] = 24 SOPs Lampe, Hach, Menzer, Nanotron; Lee, Orthotron

  41. Selection Criteria Document Topic Signal Acquisition: Block-diagram Differential Detector (T1) Select Largest A/D Symbol De-Mapper Data Differential Detector (T2) Lampe, Hach, Menzer, Nanotron; Lee, Orthotron

  42. Selection Criteria Document Topic Signal Acquisition: Miss Detection Probability n=2 Preamble Detection Lampe, Hach, Menzer, Nanotron; Lee, Orthotron

  43. Selection Criteria Document Topic Signal Acquisition • Although DBO-CSS could use a shorter preamble, for consistency with IEEE 802.15.4-2003 this DBO-CSS proposal is based upon a preamble of 32 symbols which at 1MS/s is 32 µs • Existing implementations demonstrate that modules, which might be required to be adjusted for reception (gain control, frequency control, peak value estimation, etc.), can settle in this time Lampe, Hach, Menzer, Nanotron; Lee, Orthotron

  44. Selection Criteria Document Topic Clear Channel Assessment Lampe, Hach, Menzer, Nanotron; Lee, Orthotron

  45. Selection Criteria Document Topic System Performance • Since this proposal refers to the 2.4GHz ISM band, only channel models with complete parameter sets covering this frequency range can be considered: • These are LOS Residential (CM1) and NLOS Residential (CM2). • The SCD requirements on the payload size to be simulated seem to be somewhat inconsistent. At some point 10 packets with 32 bytes are mentioned which would be a total of 2560 bits. On the other hand a PER of 1% is required which mean simulating much more than 100 packets or 25600 bits. • Accurate results are obtained when large number of independent transmissions of symbols are simulated. • BER is , with N = number bits. • For example, with PER=1% and N=256 (32 octets) we get BER=3.9258E-5 Lampe, Hach, Menzer, Nanotron; Lee, Orthotron

  46. Selection Criteria Document Topic Channel Model: LOS Residential (CM1) Lampe, Hach, Menzer, Nanotron; Lee, Orthotron

  47. Selection Criteria Document Topic Channel Model: NLOS Residential (CM2) Lampe, Hach, Menzer, Nanotron; Lee, Orthotron

  48. Selection Criteria Document Topic System Performance: PER (CM2) • Transmit power of 10 dBm • 1 MBit / sec • No FEC Lampe, Hach, Menzer, Nanotron; Lee, Orthotron

  49. Selection Criteria Document Topic System Performance • Simulation over 100 channel impulse responses (as required in the SCD) were performed for channel model 1 and channel model 2. • No bit errors could be observed on channel model 1 (simulated range was 10 to 2000m). This is not really surprising because this model has a very moderate increase of attenuation over range (n=1.79) • The results for channel model 2 are presented. The parameter n=4.48 indicates a very high attenuation for higher ranges. The results were interpreted as PER respectively and for convenience were plotted twice (linear and log y scale). Lampe, Hach, Menzer, Nanotron; Lee, Orthotron

  50. Data Rate : 1Mbps (QPSK) / 500kbps (BPSK) System Performance 0 10 AWGN CM8 CM1 CM5 -1 10 -2 PER 10 -3 10 -4 10 10 12 14 16 18 20 22 Eb/No Selection Criteria Document Topic System Performance • This figure shows the analytical BER values for 2-ary orthogonal coherent and non coherent detection and the corresponding simulation results (1E7 symbols) for up down chirp (using the chirp signals defined above) • The performance loss due to the non-orthogonality of up and down chirps is very small. Lampe, Hach, Menzer, Nanotron; Lee, Orthotron