1. doc.: IEEE 802.15-05-0240-02-004a Submission May 2005 Welborn (Freescale) Slide 1 Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs) Submission Title: [ TG4a Frequency Band Proposal] Date Submitted: [May 2004] Source: [Matt Welborn] Company [Freescale Semiconductor, Inc] Address [8133 Leesburg Pike, Vienna VA 22182] Voice:[703-269-3000], FAX: [], E-Mail:[matt.welborn @ freescale.com] Re: [Response to Call for Proposals] Abstract:[This document describes a frequency band proposal for the TG4a baseline draft standard.] Purpose:[Proposal Presentation for the IEEE802.15.4a 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.

2. doc.: IEEE 802.15-05-0240-02-004a Submission May 2005 Welborn (Freescale) Slide 2 Design Consideration TG4a is committed to support both coherent and non- coherent receiver architectures –Supports a wide range of applications that require different balances of complexity and performance –Provides flexibility to address evolving applications Areas of tension –PRF –Peak power – NC benefits from higher peak power –Higher peak power leads to higher complexity/cost –Ranging – precisely resolve details of multipath response (“leading edge” detection) Processing gain – Impulse radio

3. doc.: IEEE 802.15-05-0240-02-004a Submission May 2005 Welborn (Freescale) Slide 3 Advantages Meets requirements of TG4a baseline draft Uses non-uniform bandwidths for mandatory and two optional narrow bands –Allows same pass-band pulse shape to be used in each band (simplifies pulse generation) –Provides more uniform performance for each of three narrow bands PRF would also scale with changing center frequency to allow fixed (integer) relationship between center frequency, BW and chip rate

4. doc.: IEEE 802.15-05-0240-02-004a Submission May 2005 Welborn (Freescale) Slide 4 Details of proposed system Proposed waveform is similar to others proposed by Samsung, Mitsubishi, Time Domain and I2R –Should make it easier to get group support Data symbols are transmitted using short sequences of pulses with “silent” periods –Allows coherent reception and also “energy collector” or “energy detector” architecture as well –Should support implementing low-power, low-complexity devices and still provide good performance in multipath

5. doc.: IEEE 802.15-05-0240-02-004a Submission May 2005 Welborn (Freescale) Slide 5 Next potential active time 32 chip sequence 32 One Bit The Other Bit Always Empty Only 160 ns of channel multipath tolerance in this case. We transmit one or the other of these patterns to carry data. Always Empty 32 Optionally Empty Next potential active time 32 chip times 32 Always Empty 32 Optionally Empty Signals already proposed by Others (Mitsubishi, TDC, I2R, etc)

6. doc.: IEEE 802.15-05-0240-02-004a Submission May 2005 Welborn (Freescale) Slide 6 Use a Systematic Code to Compute a Redundant Bit Rate-½ convolutional encoder –Produce multiple coded bits from each data bit –Encoder itself is very low complexity Special case of convolutional code is a “systematic” code –First coded bit is same as input data bit –Second coded bit is computed by encoder –Code can be chosen to have desired constraint length (TBD) & code gain (not limited to a specific constraint length) Mapping coded bits to waveform –Map first coded bit (systematic bit) into position for BPPM –Map second coded bit into phase Can be extended to more general (non-systematic) codes very easily x2x2 x 1 =b k bkbk Convolutional Encoder

7. doc.: IEEE 802.15-05-0240-02-004a Submission May 2005 Welborn (Freescale) Slide 7 X 1 = 0, X 2 = 0 X 1 = 1, X 2 = 1 X 1 = 1, X 2 = 0 X 1 = 0, X 2 = 1 Non-coherent receiver only sees position –Demodulates only x 1 –No Viterbi decoding required (easy since x 1 =b k ) –Achieves no coding gain, assumes b k = x 1  Done. Coherent receiver demodulates position and phase –Decodes x 1 & x 2 –Viterbi decoding used to estimate original bit, b k –Achieves coding gain of original rate ½ code Non-Coherent and Coherent Demodulation

8. doc.: IEEE 802.15-05-0240-02-004a Submission May 2005 Welborn (Freescale) Slide 8 Another way to look at this Mapping Encoding two coded bits requires a 4-point signal constellation –Each axis represents one of two possible positions (orthogonal axes) –Phase of pulse determines sign of constellation point on axis  4-BOK Non-coherent receiver is insensitive to phase – see only two points in constellation  2-PPM Support for OOK receiver is possible by demodulating only one of the two dimensions (i.e. just look at first position: pulse or not?) OOK constellation 2-PPM constellation 2-PPM constellation 4-BOK (coherent) constellation Non-coherent receiver cannot see these

9. doc.: IEEE 802.15-05-0240-02-004a Submission May 2005 Welborn (Freescale) Slide 9 Multipath can Degrade the Symbol Orthogonality 2-PPM Constellation In multipath 2-PPM Constellation in AWGN

10. doc.: IEEE 802.15-05-0240-02-004a Submission May 2005 Welborn (Freescale) Slide 10 Choosing the Chip Rate and Symbol Rate Resulting waveform has “uniformly” spaced pulses (underlying chip-rate clock is constant), but exactly one-half of pulses have non-zero amplitude –PSD should be same as pulse spectrum (flat), since pulse phase is i.i.d. (TBD) Chip rate can be chosen to allow effective non-coherent demodulation in multipath –Choose T chip = (1/F chip ) > ~delay spread –Above waveform shown with (one symbol) = (two chips) [not to scale] –In general, (one symbol) = N x (2 chips) in order to spread symbol –N is chosen to achieve desired lower data rates Allows fully coherent BPSK receiver, with NO LOSS in performance Also allows non-coherent receiver using PPM or OOK demodulation T chip T symbol

11. doc.: IEEE 802.15-05-0240-02-004a Submission May 2005 Welborn (Freescale) Slide 11 Expanded View of 24-chip Burst Sequence Similar signal using 24-pulse sequence Can use coherent or non-coherent receiver T s = 109 ns T m = ~218 ns Can use PPM/OOK by sending pulse burst in Either first or second bit location 24-chip codes sent at 221 MHz rate (~4.5 ns per pulse) The “burst” rate is an average 2.3 MHz for the 2-PPM mode One BPPM symbol

12. doc.: IEEE 802.15-05-0240-02-004a Submission May 2005 Welborn (Freescale) Slide 12 Proposed Signal uses 24-chip pulse sequence, similar to original “Chaotic” noise signals and can support Non- coherent Receivers Original signal proposed by Samsung for non-coherent receiver Similar signal using 24-pulse sequence Can use coherent or non-coherent receiver T s = 109 ns T m = ~218 ns T s = 100 ns T m = 400 ns Can use PPM/OOK by sending pulse burst in Either first or second bit location

13. doc.: IEEE 802.15-05-0240-02-004a Submission May 2005 Welborn (Freescale) Slide 13 Frequency Plan Band No.Bandwidth (MHz) Low Freq. (MHz) Center Freq. (MHz) High Freq. (MHz) 1(optional)500+316434323700 2 (Mandatory)500+370239784254 3 (optional)500+424145244807 4 (optional)1500+314939784806 3 45 GHz 3.54.53.253.754.254.75 123 Band No. 4

14. doc.: IEEE 802.15-05-0240-02-004a Submission May 2005 Welborn (Freescale) Slide 14 Frequency Factorization Center Frequency Fine Chip Rate Factorization 3432 MHz190.67 MHz2x2x2x3x11x13 3978 MHz221 MHz2x3x3x13x17 4524 MHz251.33 MHz2x2x3x13x29

15. doc.: IEEE 802.15-05-0240-02-004a Submission May 2005 Welborn (Freescale) Slide 15 PLL Reference Diagram Oscillator Reference Divider ( R ) Divider, N Phase Det. XTAL fXfX f Comp f X (MHZ) R (MHz) f comp (MHz) 26213 19.2320.6 1226 LPFVCO output

16. doc.: IEEE 802.15-05-0240-02-004a Submission May 2005 Welborn (Freescale) Slide 16 Higher Band Frequency Plan Band No.Bandwidth (MHz) Low Freq. (MHz) Center Freq. (MHz) High Freq. (MHz) 5(optional)1000+638768647341 6 (optional)1000+740479568509 7 (optional)1000+842090489676 8 (optional)~3000629879569615 6 810 GHz 796.57.58.59.5 567 Band No. 8

17. doc.: IEEE 802.15-05-0240-02-004a Submission May 2005 Welborn (Freescale) Slide 17 One possible mapping of pulses to bits: Use 31-chip Codes Symb ol Cyclic shift to right by n chips, n= 31-Chip value 000+ - - 0 0 0 + - 0 + + + 0 + 0 - 0 0 0 0 + 0 0 - 0 - + 0 0 - - 018- 0 - + 0 0 - - + - - 0 0 0 + - 0 + + + 0 + 0 - 0 0 0 0 + 0 0 1116- 0 0 0 0 + 0 0 - 0 - + 0 0 - - + - - 0 0 0 + - 0 + + + 0 + 0 1024- 0 + + + 0 + 0 - 0 0 0 0 + 0 0 - 0 - + 0 0 - - + - - 0 0 0 + 1.Can support both coherent and non-coherent pulse compression 2.Add 33 zero chips to get baseline mode for non-coherent receivers 3.However, these codes have poor spectral properties (see following slides)

18. doc.: IEEE 802.15-05-0240-02-004a Submission May 2005 Welborn (Freescale) Slide 18 Signal structure using a 31-chip Burst Sequence Hypothetical signal using 31-pulse sequence Can use coherent or non-coherent receiver T s = 140 ns T m = ~290 ns Can use PPM/OOK by sending pulse burst in Either first or second bit location Based on same 31-chip sequences proposed by Francois Chin of I2R at ~4.5 ns T c spacing These codes need to be further analyzed to make sure spectral properties are acceptable

19. doc.: IEEE 802.15-05-0240-02-004a Submission May 2005 Welborn (Freescale) Slide 19 PSD plots for Proposed 31-chip codes – These codes cost 5 dB or more in Tx power

20. doc.: IEEE 802.15-05-0240-02-004a Submission May 2005 Welborn (Freescale) Slide 20 The Impact of a PSD As we see, the PSD using the 31-chip codes results in about 5 dB Tx power reduction Result is reduced range and/or robustness An alternative is to consider similar length codes that have better spectral properties –One example would be length-24 ternary codes with two “zeros” per code Codes exist that could provide only a 2 dB penalty on Tx power (see next page) Other codes exist, including “hierarchical codes”, analysis is ongoing Code Set NumberL=24 Codes 1 -1, 0, 1, -1, -1, -1, 1, 1, 0, 1, 1, 1, 1, -1, 1, -1, 1, 1, 1, -1, 1, -1, -1, 1 2 -1, -1, -1, -1, 1, -1, 1, -1, 1, -1, -1, 1, -1, 1, 1, -1, -1, 1, 1, 0, -1, 0, 1, 1 3 -1, 1, -1, -1, 1, -1, -1, 1, -1, 0 -1, 0, -1, -1, 1, 1, 1, -1, 1, 1, 1, -1, -1, -1 4 0, -1, -1, -1, -1, -1, -1, 1, 1, 0, -1, 1, 1, -1, 1, -1, -1, 1, 1, -1, 1, -1, 1, -1 5 -1, 1, -1, 1, 1, -1, 1, 0, 1, 1, 1, -1, -1, 1, 1, -1, 1, 1, 1, -1, -1, -1, 0, -1 6 0, -1, -1, 0, 1, -1, -1, 1, -1, -1, 1, 1, 1, 1, -1, -1, 1, -1, 1, -1, 1, 1, 1, 1

21. doc.: IEEE 802.15-05-0240-02-004a Submission May 2005 Welborn (Freescale) Slide 21 PSD plots for Proposed 24-chip codes Multiple codes are available with only ~2 dB backoff

22. doc.: IEEE 802.15-05-0240-02-004a Submission May 2005 Welborn (Freescale) Slide 22 PSD plots for Barker 11 & 13 codes (for reference) 23456 x 10 9 -70 -65 -60 -55 -50 -45 -40 -35 Barker-13 Back-off = -2.8395 dB 23456 x 10 9 -70 -65 -60 -55 -50 -45 -40 -35 Barker-11 Back-off = -1.1789 dB

23. doc.: IEEE 802.15-05-0240-02-004a Submission May 2005 Welborn (Freescale) Slide 23 Expanded View of 24-chip Burst Sequence Similar signal using 24-pulse sequence Can use coherent or non-coherent receiver T s = 109 ns T m = ~218 ns Can use PPM/OOK by sending pulse burst in Either first or second bit location 24-chip codes sent at 221 MHz rate (~4.5 ns per pulse) The “burst” rate is an average 2.3 MHz for the 2-PPM mode One BPPM symbol

24. doc.: IEEE 802.15-05-0240-02-004a Submission May 2005 Welborn (Freescale) Slide 24 Bandwidth*552 MHz [= 442 MHz @ 3-dB * 1.25 for excess BW] Pulse Burst Frequency (symbol rate)2.3 MHz [= 1/(2*T m )] # Chip / symbol (Code length)24-chip sequence + 24-chip “zero” padding (silence) “Chip rate” inside burst221 MHz (= F center / 18) Channel codingConvolutional code K = 4, r=3/4 (low complexity) Symbol RateSame as Pulse burst frequency above Mandatory bit rate3/4 x 2.3 MSymbols/s = 1.73 Mbps Optional bit rates (others possible) (For “coherent-only” higher rate modes, no zero padding is used so the symbol rate is 1/T m) 3/4 x 1.15 MSps = 0.86 Mbps (non-coherent) 3/4 x 4.6 MSps = 3.45 Mbps (non-coherent ) 3/4 x 9.2 MSps = 6.9 Mbps (coherent) 3/4 x 18.4 MSps = 13.8 Mbps (coherent) Lower bit rate scalabilitySymbol Repetition Modulation{+1,-1} bipolar and PPM/OOK of ternary pulse train Total # simultaneous piconets supported 6 per FDM band Multiple access for piconetsCDM (fixed code) + FDM (fixed band) Proposed System Parameters (Mandatory Center Band) Bandwidth: Optional bands #1 & 3 are slightly different BW and frequency as noted on previous slides Wide band #4 uses narrower pulses to achieve higher bandwidth

25. doc.: IEEE 802.15-05-0240-02-004a Submission May 2005 Welborn (Freescale) Slide 25 PRF and Data Rate Details FrefMultFcenter (MHz)DivideFchip (MHz) Seq Len (chip s)"Burst" Duration (nsec)"Gap" Len (chips)"Burst" Duration (nsec)Tot Time# PPM Slots Symbol rate (MH z)FEC Data rate (Mbp s) Low Band 1326434323695.3324251.7524251.75503.5020.991 13264343218190.6724125.8724125.87251.7521.991 1326434329381.332462.942462.94125.8723.971 1326434329381.332462.942462.94125.8717.940.755.96 1326434329381.332462.9400.0062.94115.890.7511.92 Middle Band (mandatory) 13306397836110.5024217.1924217.19434.3921.151 13306397818221.0024108.6024108.60217.1922.301 1330639789442.002454.302454.30108.6024.601 1330639789442.002454.302454.30108.6019.210.756.91 1330639789442.002454.3000.0054.30118.420.7513.81 High Band 13348452436125.6724190.9824190.98381.9621.311 13348452418251.332495.492495.49190.9822.621 1334845249502.672447.752447.7595.4925.241 1334845249502.672447.752447.7595.49110.470.757.85 1334845249502.672447.7500.0047.75120.940.7515.71

26. doc.: IEEE 802.15-05-0240-02-004a Submission May 2005 Welborn (Freescale) Slide 26 RFD and FFD Class Devices TG4 Standard contains the concept of Reduced Functionality and Full-functionality devices (RFD & FFD) Proposal is to allow RFD to have only non-coherent receiver Will have reduced operating range, but also potentially lower complexity RFD may have slightly lower ranging capabilities –TOA ranging (when SNR is adequate) –Maybe only Tx for TDOA-2 ranging FFD can form and coordinate piconet for low cost/low complexity RFD radios –RFD-only piconets at short range? RFD can use simple non-coherent receiver for OOK or PPM FFD Coherent Receiver = FFD

27. doc.: IEEE 802.15-05-0240-02-004a Submission May 2005 Welborn (Freescale) Slide 27 Possible Techniques to Optimize Radio Operations for Dynamic Conditions RFD/FFD  FFD: Must transmit signal that provided FFD- RX performance FFD/RFD  RFD: can transmit non- coherent only signal Every link will connect a transmitter and a receiver – these may be a different mix of capability for each link Applications that are sensitive to power and/or cost may want to match their operation to dynamic conditions such as –Capabilities of the intended receiver (coherent vs. non-coherent) –Dynamic channel, noise, interference or path loss conditions Example: a small homogeneous cluster of low-complexity (non- coherent) radios want to operate at short range – can they operate in a lower complexity Dynamically changing –Transmit power –Non-coherent vs. coherent pulses Example: –Preamble length –PRF –Spectral shape

28. doc.: IEEE 802.15-05-0240-02-004a Submission May 2005 Welborn (Freescale) Slide 28 TOA Ranging for both FFD and RFD Mobile (x m,y m ) Anchor 2 (x A2,y A2 ) Anchor 3 (x A3,y A3 ) Anchor 1 (x A1,y A1 ) Positioning from TOA 3 anchors with known positions (at least) are required to retrieve a 2D-position from 3 TOAs Measurements Estimated Position Specific Positioning Algorithms

29. doc.: IEEE 802.15-05-0240-02-004a Submission May 2005 Welborn (Freescale) Slide 29 TDOA Ranging Requires FFDs to Act as “Reference Nodes” Key: Sync Pulse Location Pulse TDOA backhaul Mode 2 - Active Controller: Can be wired or wireless connection to FFDs Needs protocol to allow synchronizing clocks SOI = RFD – only needs to transmit signal when TDOA ranging FFD reference node = FFD