January 2005 IEEE15 05 0002 00 004 a

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January 2005 IEEE-15 -05 -0002 -00 -004 a Project: IEEE P 802. 15 Working

January 2005 IEEE-15 -05 -0002 -00 -004 a Project: IEEE P 802. 15 Working Group for Wireless Personal Area Networks (WPANs) Submission Title: Chirp Spread Spectrum (CSS) PHY Presentation for 802. 15. 4 a Date Submitted: January 04, 2005 Source: John Lampe Company: Nanotron Technologies Address: Alt-Moabit 61, 10555 Berlin, Germany Voice: +49 30 399 954 135, FAX: +49 30 399 954 188, E-Mail: j. lampe@nanotron. com Re: This is in response to the TG 4 a Call for Proposals, 04/0380 r 2 Abstract: The Nanotron Technologies Chirp Spread Spectrum is described and the detailed response to the Selection Criteria document is provided Purpose: Submitted as the candidate proposal for TG 4 a Alt-PHY Notice: This document has been prepared to assist the IEEE P 802. 15. It is offered as a basis for discussion and is not binding on the contributing individual(s) or organization(s). The material in this document is subject to change in form and content after further study. The contributor(s) reserve(s) the right to add, amend or withdraw material contained herein. Release: The contributor acknowledges and accepts that this contribution becomes the property of IEEE and may be made publicly available by P 802. 15. Submission 1 J. Lampe, R. Hach, L. Menzer, Nanotron

January 2005 IEEE-15 -05 -0002 -00 -004 a Chirp Spread Spectrum (CSS) PHY Presentation

January 2005 IEEE-15 -05 -0002 -00 -004 a Chirp Spread Spectrum (CSS) PHY Presentation for 802. 15. 4 a by John Lampe, Rainer Hach, & Lars Menzer Nanotron Technologies Gmb. H Berlin, Germany www. nanotron. com Submission 2 J. Lampe, R. Hach, L. Menzer, Nanotron

January 2005 IEEE-15 -05 -0002 -00 -004 a General Properties of Chirp Signals •

January 2005 IEEE-15 -05 -0002 -00 -004 a General Properties of Chirp Signals • Simplicity – Basically a 2 ary baseband transmission – The ‘windowed chirp’ is a linear frequency sweep with a total duration of 1 us Submission 3 J. Lampe, R. Hach, L. Menzer, Nanotron

January 2005 IEEE-15 -05 -0002 -00 -004 a Chirp Properties (cont. ) • Real

January 2005 IEEE-15 -05 -0002 -00 -004 a Chirp Properties (cont. ) • Real part of a windowed up-chirp signal with a total duration of 1 us Submission 4 J. Lampe, R. Hach, L. Menzer, Nanotron

January 2005 IEEE-15 -05 -0002 -00 -004 a Chirp Properties (cont. ) • Figure

January 2005 IEEE-15 -05 -0002 -00 -004 a Chirp Properties (cont. ) • Figure shows the autocorrelation function (acf) and cross-correlation function (ccf) of the signal described above – Note that the ccf has a constant low value (compared to DS sequences). Submission 5 J. Lampe, R. Hach, L. Menzer, Nanotron

January 2005 IEEE-15 -05 -0002 -00 -004 a Chirp Properties (cont. ) • This

January 2005 IEEE-15 -05 -0002 -00 -004 a Chirp Properties (cont. ) • This figure shows the PSD of the signal with a power of 10 d. Bm • By padding the signal with zeros the “frequency resolution” has been set to 100 k. Hz so that the plot is similar to what a spectrum analyzer would measure. • At 12 MHz offset from the center is below -30 d. Bm (which is the ETSI requirement for out of band emissions) Submission 6 J. Lampe, R. Hach, L. Menzer, Nanotron

January 2005 IEEE-15 -05 -0002 -00 -004 a Chirp Properties (cont. ) • Further

January 2005 IEEE-15 -05 -0002 -00 -004 a Chirp Properties (cont. ) • Further processing of the signals Sig A and Sig B for symbol detection could be done in coherent (real part processing) or non coherent manner (envelope filtering). – Since the analytical results are well known for AWGN channels we will mention these – Simulations over other channels will all refer to the non coherent system as drawn below. Submission 7 J. Lampe, R. Hach, L. Menzer, Nanotron

January 2005 IEEE-15 -05 -0002 -00 -004 a Chirp Properties (cont. ) • This

January 2005 IEEE-15 -05 -0002 -00 -004 a Chirp Properties (cont. ) • This figure shows the analytical BER values for 2 ary orthogonal coherent and non coherent detection and the corresponding simulation results (1 E 5 symbols) for up down chirp (using the chirp signals defined above) • The performance loss due to the non-orthogonality of up and down chirp is very small. Submission 8 J. Lampe, R. Hach, L. Menzer, Nanotron

January 2005 IEEE-15 -05 -0002 -00 -004 a Signal Robustness • The proposed CSS

January 2005 IEEE-15 -05 -0002 -00 -004 a Signal Robustness • The proposed 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 (v 1. 2 has adaptive hopping) via DFS • • 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. Submission 9 J. Lampe, R. Hach, L. Menzer, Nanotron

January 2005 IEEE-15 -05 -0002 -00 -004 a Support for Interference Ingress • Example

January 2005 IEEE-15 -05 -0002 -00 -004 a Support for Interference Ingress • Example (w/o FEC): – – – Bandwidth B of the chirp = 20 MHz Duration time T of the chirp = 1 µs Center frequency of the chirp (ISM band) = 2. 442 GHz Processing gain, BT product of the chirp = 13 d. B Eb/N 0 at detector input (BER=10 -4) = 12 d. B In-band carrier to interferer ratio (C/I @ BER=10 -4) = 12 - 13 = -1 d. B – Implementation Loss = 2 d. B Submission 10 J. Lampe, R. Hach, L. Menzer, Nanotron

January 2005 IEEE-15 -05 -0002 -00 -004 a Support for Interference Egress • Low

January 2005 IEEE-15 -05 -0002 -00 -004 a Support for Interference Egress • Low interference egress • IEEE 802. 11 b receiver – More than 30 d. B of protection in an adjacent channel – Almost 60 d. B in the alternate channel • these numbers are similar for the 802. 11 g receiver Submission 11 J. Lampe, R. Hach, L. Menzer, Nanotron

January 2005 IEEE-15 -05 -0002 -00 -004 a Regulatory • Devices manufactured in compliance

January 2005 IEEE-15 -05 -0002 -00 -004 a Regulatory • Devices manufactured in compliance with the 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 CSS proposal would adhere to the following worldwide regulations: – – Submission United States Part 15. 247 or 15. 249 Canada DOC RSS-210 Europe ETS 300 -328 Japan ARIB STD T-66 12 J. Lampe, R. Hach, L. Menzer, Nanotron

January 2005 IEEE-15 -05 -0002 -00 -004 a Scalability – Data Rate • Mandatory

January 2005 IEEE-15 -05 -0002 -00 -004 a Scalability – Data Rate • Mandatory rate = 1 Mb/s • Optional rate = 267 Kb/s • Other possible data rates include 2 Mb/s to allow better performance in a burst type, interference limited environment or a very low energy consumption application • 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. Submission 13 J. Lampe, R. Hach, L. Menzer, Nanotron

January 2005 IEEE-15 -05 -0002 -00 -004 a Scalability – Frequency Bands • The

January 2005 IEEE-15 -05 -0002 -00 -004 a Scalability – Frequency Bands • The proposer is confident that the CSS proposal would also work well in other frequency bands – Including the 5975 to 7250 MHz band • Mentioned in the new FCC operating rules “SECOND REPORT AND ORDER AND SECOND MEMORANDUM OPINION AND ORDER” released December 16, 2004 Submission 14 J. Lampe, R. Hach, L. Menzer, Nanotron

January 2005 IEEE-15 -05 -0002 -00 -004 a Scalability – Data Whitener • Additionally,

January 2005 IEEE-15 -05 -0002 -00 -004 a Scalability – Data Whitener • Additionally, the group may consider the use of a data whitener, similar to those used by Bluetooth and IEEE 802. 11 to produce a more “noise-like” spectrum and allow better performance in synchronization and ranging. Submission 15 J. Lampe, R. Hach, L. Menzer, Nanotron

January 2005 IEEE-15 -05 -0002 -00 -004 a Scalability – Power Levels • For

January 2005 IEEE-15 -05 -0002 -00 -004 a Scalability – Power Levels • For extremely long ranges the transmit power may be allowed to rise to each country’s regulatory limit – For example the US would allow 30 d. Bm of output power with up to a 6 d. B gain antenna – The European ETS limits would specify 20 d. Bm of output power with a 0 d. B gain antenna • Note that even though higher transmit 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 • In this manner the averaged transmitter current drain will be less than the averaged receiver current drain. Submission 16 J. Lampe, R. Hach, L. Menzer, Nanotron

January 2005 IEEE-15 -05 -0002 -00 -004 a Scalability – Backward Compatibility • Due

January 2005 IEEE-15 -05 -0002 -00 -004 a Scalability – Backward Compatibility • Due to some of 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 CSS and DSSS correlators • It is anticipated that this backward compatibility could be achieved via mode switching versus a dynamic change on-thefly technique – left up to the implementer • This backward compatibility would be a significant advantage to the marketplace by allowing these devices to communicate with existing 802. 15. 4 infrastructure and eliminating customer confusion Submission 17 J. Lampe, R. Hach, L. Menzer, Nanotron

January 2005 IEEE-15 -05 -0002 -00 -004 a Mobility Values • Communication – No

January 2005 IEEE-15 -05 -0002 -00 -004 a Mobility Values • 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 due to high relative speed vrel between two devices • Such situations also occur when one device is mounted on a rotating machine • The limits will be determined by other, general processing modules (AGC, symbol synchronization, . . . ) • 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 • We assume that the longest time in this procedure is the turnaround time tturn between the two nodes which will be determined by the respective u. C performance. During this time the change of distance should stay below the accuracy da required by the application. • • • Submission 18 For da =1 m tturn =10 ms this yields vrel << 100 m/s J. Lampe, R. Hach, L. Menzer, Nanotron

January 2005 IEEE-15 -05 -0002 -00 -004 a MAC Enhancements and Modifications • There

January 2005 IEEE-15 -05 -0002 -00 -004 a MAC Enhancements and Modifications • There are no 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 TG 4 b be used to support the new channels. There will be an addition to the PHYSAP 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 that are expected to be developed by the Ranging subcommittee. Submission 19 J. Lampe, R. Hach, L. Menzer, Nanotron

January 2005 IEEE-15 -05 -0002 -00 -004 a Channel Models • Since this proposal

January 2005 IEEE-15 -05 -0002 -00 -004 a Channel Models • Since this proposal refers to the 2. 4 GHz ISM band, only channel models with complete parameter set covering this frequency range can be considered – • • At the time being these are LOS Residential (CM 1) and NLOS Residential (CM 2). The 100 realizations for each channel model were bandpass filtered with +-15 MHz around 2. 437 GHz which corresponds to the second of the three sub-bands proposed. The filtered impulse responses were down converted to complex baseband. The magnitudes over time are shown in the following plots Furthermore some graphs of the function H_tilde as described and required in the SCD are shown For now we assume that the neighbor sub-bands will not differ significantly from the center sub-band that we restrict simulations on the center sub-band 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 more than 100 packets or 25600 bits. Since the delay spread and thus the time in which subsequent symbols can influence each other of all given channel impulse responses are well below the symbol duration of 1 us suggested by this proposal we believe that we get the best results when we simulate a large number of independent transmissions of symbols. Assuming an equal probability of error for all bits of a packet we can give the relationship between the BER and PER by With N being the number of payload bits. • Thus we can calculate the BER which is required for any PER: • For PER=1% and N=256 we get BER=3. 9258 E-5 Submission 20 J. Lampe, R. Hach, L. Menzer, Nanotron

January 2005 IEEE-15 -05 -0002 -00 -004 a Channel Model 1 Submission 21 J.

January 2005 IEEE-15 -05 -0002 -00 -004 a Channel Model 1 Submission 21 J. Lampe, R. Hach, L. Menzer, Nanotron

January 2005 IEEE-15 -05 -0002 -00 -004 a Channel Model 2 Submission 22 J.

January 2005 IEEE-15 -05 -0002 -00 -004 a Channel Model 2 Submission 22 J. Lampe, R. Hach, L. Menzer, Nanotron

January 2005 IEEE-15 -05 -0002 -00 -004 a Size and Form Factor • The

January 2005 IEEE-15 -05 -0002 -00 -004 a Size and Form Factor • The implementation of the CSS proposal will be much less than SD Memory at the onset – following the form factors of Bluetooth and IEEE 802. 15. 4/Zig. Bee • The implementation of this device into a single chip is relatively straightforward – As evidenced in the “Unit Manufacturing Complexity” slides Submission 23 J. Lampe, R. Hach, L. Menzer, Nanotron

January 2005 IEEE-15 -05 -0002 -00 -004 a PHY SAP Payload Bit Rate &

January 2005 IEEE-15 -05 -0002 -00 -004 a PHY SAP Payload Bit Rate & Data Throughput • The PPDU is composed of several components as shown in the figure below • The following figure shows in greater detail, the component parts of each PPDU. Octets: 4 1 Preamble SFD SHR Submission 1 Frame length (8 bits) PHR 24 Variable (up to 256) PHY payload PSDU J. Lampe, R. Hach, L. Menzer, Nanotron

January 2005 IEEE-15 -05 -0002 -00 -004 a PHY SAP Payload Bit Rate &

January 2005 IEEE-15 -05 -0002 -00 -004 a PHY SAP Payload Bit Rate & Data Throughput (cont) • • 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 us) 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 Submission 25 J. Lampe, R. Hach, L. Menzer, Nanotron

January 2005 IEEE-15 -05 -0002 -00 -004 a PHY SAP Payload Bit Rate &

January 2005 IEEE-15 -05 -0002 -00 -004 a PHY SAP Payload Bit Rate & Data Throughput (cont) • The figures show the structure, as defined in the IEEE Standard 802. 15. 4 and the SCD – cases of acknowledged transmissions as used in section 3. 2. 1 values and for unacknowledged transmissions. • For this proposal, the value of Tack and SIFS are retained from the IEEE Standard 802. 15. 4 and are each 192 microseconds • The value of LIFS is also shown as 192 microseconds. – Additional revisions of this proposal may show a different value as the authors discuss the need for longer LIFS values with members of TG 4 b – The values of SIFS and LIFS have a MAC dependency above the value of 192 u. S required for PHY turn around – SIFS has a value of 192 us (12 symbols) in the current standard and LIFS has a value of 40 symbols. Submission 26 J. Lampe, R. Hach, L. Menzer, Nanotron

January 2005 IEEE-15 -05 -0002 -00 -004 a Simultaneous Operating Piconets • Separating Piconets

January 2005 IEEE-15 -05 -0002 -00 -004 a Simultaneous Operating Piconets • Separating Piconets by frequency division – This 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 chirp signal defined earlier 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. Submission 27 J. Lampe, R. Hach, L. Menzer, Nanotron

January 2005 IEEE-15 -05 -0002 -00 -004 a Signal Acquisition • The signal acquisition

January 2005 IEEE-15 -05 -0002 -00 -004 a Signal Acquisition • The signal acquisition is basically determined by the structure and duration of the preamble – In contrast to ‘always on’ systems like DECT or GSM – Low duty rate systems must be able to acquire a signal without any prior knowledge about that signal’s level or timing – While the IEEE 802. 15. 4 -2003 uses a preamble duration of 32 symbols (128 µs at 2. 4 GHz) other commercially available transceiver chips (e. g. nano. NET TRX from Nanotron) use 30 symbols at 1 MS/s (i. e. 30µs). • • For consistency with IEEE 802. 15. 4 -2003 this CSS proposal is based upon a preamble of 32 symbols which at 1 MS/s turns out as 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 be setup in such a time duration The probability of missing a packet is then simply determined by the probability that the SFD is received correctly As shown before, the BER required for a PER of 1%, is BER=3. 9258 E-5 Submission 28 J. Lampe, R. Hach, L. Menzer, Nanotron

January 2005 IEEE-15 -05 -0002 -00 -004 a Clear Channel Assessment • A combination

January 2005 IEEE-15 -05 -0002 -00 -004 a Clear Channel Assessment • A combination of symbol detection (SD) and energy detection (ED) has proven to be useful in practice. The duration of the preamble can be used as upper bound for the duration for both detection mechanism. By providing access to the threshold for ED the system allows the application to adjust its behavior (false alarm vs. miss probability) according to its needs. Submission 29 J. Lampe, R. Hach, L. Menzer, Nanotron

January 2005 IEEE-15 -05 -0002 -00 -004 a System Performance • Simulation over 100

January 2005 IEEE-15 -05 -0002 -00 -004 a 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 2000 m). 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 displayed below. The parameter n=4. 48 indicates a very high attenuation for higher ranges. The results were interpreted as BER and PER respectively and for convenience were plotted twice (linear and log y scale). Submission 30 J. Lampe, R. Hach, L. Menzer, Nanotron

January 2005 IEEE-15 -05 -0002 -00 -004 a System Performance Submission 31 J. Lampe,

January 2005 IEEE-15 -05 -0002 -00 -004 a System Performance Submission 31 J. Lampe, R. Hach, L. Menzer, Nanotron

January 2005 IEEE-15 -05 -0002 -00 -004 a System Performance Submission 32 J. Lampe,

January 2005 IEEE-15 -05 -0002 -00 -004 a System Performance Submission 32 J. Lampe, R. Hach, L. Menzer, Nanotron

January 2005 IEEE-15 -05 -0002 -00 -004 a System Performance Submission 33 J. Lampe,

January 2005 IEEE-15 -05 -0002 -00 -004 a System Performance Submission 33 J. Lampe, R. Hach, L. Menzer, Nanotron

January 2005 IEEE-15 -05 -0002 -00 -004 a TOA Estimation for Ranging Noise and

January 2005 IEEE-15 -05 -0002 -00 -004 a TOA Estimation for Ranging Noise and Jitter of Band-Limited Pulse Given a band-limited pulse with noise σu we want to estimate how the jitter (timing error) σt with which the passing of the rising edge of the pulse through a given threshold can be detected is effected by the bandwidth B. We approximate the impact of σu by the simple formula: The assume the rising speed of a the signal being proportional to the signal bandwidth: Since the power σ2 of band-filtered AWGN is proportional to the bandwidth we know that: Which leads to: Submission 34 J. Lampe, R. Hach, L. Menzer, Nanotron

January 2005 IEEE-15 -05 -0002 -00 -004 a Symmetrical Double-Sided Two-Way Ranging (SDS TWR)

January 2005 IEEE-15 -05 -0002 -00 -004 a Symmetrical Double-Sided Two-Way Ranging (SDS TWR) Tround. A Treply. A Node A Tprop t Node B Treply. B Tround. . . round trip time Treply. . . reply time Double-Sided: Each node executes a round trip measurement. Tprpp. . . propagation of pulse Symmetrical: Reply Times of both nodes are identical (Treply. A =Treply. B). Results of both round trip measurements are used to calculate the distance. Submission 35 J. Lampe, R. Hach, L. Menzer, Nanotron t

January 2005 IEEE-15 -05 -0002 -00 -004 a Ranging - Effect of Time Base

January 2005 IEEE-15 -05 -0002 -00 -004 a Ranging - Effect of Time Base Offset Errors Assuming offset errors e. A, e. B of the timebases of node A and B we get: On the condition that the two nodes have almost equal behavior, we can assume: This has the effect that timebase offsets are canceled out: Calculations show that for 40 ppm crystals and 20 us max difference between Tround. A and Tround. B and between Treply. A and Treply. B an accuracy below 1 ns can easily be reached! Submission 36 final measurement error J. Lampe, R. Hach, L. Menzer, Nanotron

January 2005 IEEE-15 -05 -0002 -00 -004 a Influence of Symmetry Error: Calculation of

January 2005 IEEE-15 -05 -0002 -00 -004 a Influence of Symmetry Error: Calculation of an SDS TWR Example System • Example System Et. A = ± 40 ppm, Et. B = ± 40 ppm (worst case combination selected): ∆d (ΔTreply = 20 ns) d • ∆d (ΔTreply = 200 ns) ∆d (ΔTreply = 2 µs) ∆d (ΔTreply = 200 µs) 10 cm ± 0. 012 cm ± 0. 12 cm ± 120 cm 10 m ± 0. 05 cm ± 0. 12 cm ± 120 cm 100 m ± 0. 4 cm ± 1. 2 cm ± 120 cm 1 km ± 4 cm ± 120 cm 10 km ± 40 cm ± 120 cm Conclusion: Even 20 µs Symmetry Error allows excellent accuracy of distance ! Symmetry Error below 2 µs can be guaranteed in real implementations ! Submission 37 J. Lampe, R. Hach, L. Menzer, Nanotron

January 2005 IEEE-15 -05 -0002 -00 -004 a Principle of Dithering and Averaging pulse

January 2005 IEEE-15 -05 -0002 -00 -004 a Principle of Dithering and Averaging pulse to transmit • Dithering: Ti PHY packet to transmit Ti transmitted pulse PHY packet transmitted ΔTi 1 ΔTi 2 ΔTi 3 t ΔTin • Averaging: ΔTi. RX 1 ΔTi. RX 2 Ti Ti ΔTi. RX 3 Ti ΔTi. RXn t Ti t. To. A’ Submission 38 J. Lampe, R. Hach, L. Menzer, Nanotron

January 2005 IEEE-15 -05 -0002 -00 -004 a Simulation of a SDS TWR System

January 2005 IEEE-15 -05 -0002 -00 -004 a Simulation of a SDS TWR System Example system: Simulates SDS TWR + Dithering & Averaging Crystal Errors ± 40 ppm Single shot measurements @ 1 MBit/s data rate (DATA-ACK) Transmit Jitter = ± 4 ns (systematic/pseudo RN-Sequence) Pulse detection resolution = 4 ns Pulses averaged per packet = 32 Symmetry error = 4 µs (average) Distance = 100 m Results of Distance Error ∆d: |∆d. WC| < 50 cm |∆d. RMS| < 20 cm (ideal channel without noise) Submission 39 J. Lampe, R. Hach, L. Menzer, Nanotron

January 2005 IEEE-15 -05 -0002 -00 -004 a Link Budget footnotes [1] Rx noise

January 2005 IEEE-15 -05 -0002 -00 -004 a Link Budget footnotes [1] Rx noise figure: in addition the proposer can select other values for special purpose (e. g. 15 d. B for lower cost lower performance system) [2] The minimum Rx sensitivity level is defined as the minimum required average Rx power for a received symbol in AWGN, and should include effects of code rate and modulation. Submission 40 J. Lampe, R. Hach, L. Menzer, Nanotron

January 2005 IEEE-15 -05 -0002 -00 -004 a Sensitivity • The sensitivity to which

January 2005 IEEE-15 -05 -0002 -00 -004 a Sensitivity • The sensitivity to which this CSS proposal refers is based upon non-coherent detection – It is understood that coherent detection will allow 2 - 3 d. B better sensitivity but at the cost of higher complexity (higher cost? ) and poorer performance in some multipath limited environments • The sensitivity for the 1 Mb/s mandatory data rate is -92 d. Bm for a 1% PER in an AWGN environment with a front end NF of 7 d. B • The sensitivity for the optional 267 kb/s data rate is -97 d. Bm for a 1% PER in an AWGN environment with a front end NF of 7 d. B Submission 41 J. Lampe, R. Hach, L. Menzer, Nanotron

January 2005 IEEE-15 -05 -0002 -00 -004 a Power Management Modes • Power management

January 2005 IEEE-15 -05 -0002 -00 -004 a Power Management Modes • Power management aspects of this proposal are consistent with the modes identified in the IEEE 802. 15. 4: 2003 standard • There are no modes lacking nor added • Once again, attention is called to the 1 Mbit/s basic rate of this proposal and resulting shorter “on” times for operation Submission 42 J. Lampe, R. Hach, L. Menzer, Nanotron

January 2005 IEEE-15 -05 -0002 -00 -004 a Power Consumption The typical DSSS receivers,

January 2005 IEEE-15 -05 -0002 -00 -004 a Power Consumption The typical DSSS receivers, used by 802. 15. 4, are very similar to the envisioned CSS receiver • The two major differences are the modulator and demodulator – The modulator of the CSS is much simpler than the DSSS however since the major power consumption is the transmitter and the difference is negligible – The power consumption for a 10 d. Bm transmitter should be 198 m. W or less • The receiver for the CSS is remarkably similar to that of the DSSS with the major difference being the correlator – The correlator for the CSS uses a frequency dispersive mechanism while the DSSS uses a chip additive correlator – The difference in power consumptions between these correlators is negligible so the power consumption for a 6 d. B NF receiver should be 40 m. W or less • The power consumed during the CCA is basically similar to the receiver power consumption – All of the receiver circuits are being used during the CCA (correlator is used for the carrier detect function) Submission 43 J. Lampe, R. Hach, L. Menzer, Nanotron

January 2005 IEEE-15 -05 -0002 -00 -004 a Power Consumption (cont. ) • Power

January 2005 IEEE-15 -05 -0002 -00 -004 a Power Consumption (cont. ) • Power save mode is used most of the time for this device and has the lowest power consumption – Typical power consumptions for 802. 15. 4 devices are 3 µW or less • Energy per bit is the power consumption divided by the bit rate – The energy per bit for the 10 d. Bm transmitter is less than 0. 2 µJ – The energy per bit for the receiver is 40 n. J • As an example, the energy consumed during an exchange of a 32 octet PDU between two devices (including the transmission of the PDU, the tack, and the ack) would be 70. 6 µJ for the sender device while the receiving device consumed 33. 2 µJ – As a reference point it should be noted that according to the Duracell web site, a Duracell AA alkaline cell contains more than 12, 000 Joules of energy. Submission 44 J. Lampe, R. Hach, L. Menzer, Nanotron

January 2005 IEEE-15 -05 -0002 -00 -004 a Antenna Practicality • The antenna for

January 2005 IEEE-15 -05 -0002 -00 -004 a Antenna Practicality • The antenna for this CSS proposal is a standard 2. 4 GHz antenna such as widely used for 802. 11 b, g devices and Bluetooth devices. These antennas are very well characterized, widely available, and extremely low cost. Additionally there a multitude of antennas appropriate for widely different applications. The size for these antennae is consistent with the SCD requirement. Submission 45 J. Lampe, R. Hach, L. Menzer, Nanotron

January 2005 IEEE-15 -05 -0002 -00 -004 a Time To Market • No regulatory

January 2005 IEEE-15 -05 -0002 -00 -004 a Time To Market • No regulatory hurdles • No research barriers – no unknown blocks, CSS chips are available in the market • Normal design and product cycles will apply • Can be manufactured in CMOS Submission 46 J. Lampe, R. Hach, L. Menzer, Nanotron

January 2005 IEEE-15 -05 -0002 -00 -004 a Unit Manufacturing Complexity • Target process:

January 2005 IEEE-15 -05 -0002 -00 -004 a Unit Manufacturing Complexity • Target process: RF-CMOS, 0. 18 µm feature size Pos. Block description Estimated Area Unit 1 Receiver with high-end LNA 2. 00 mm² 2 Transmitter, Pout = + 10 d. Bm 1. 85 mm² 3 Digitally Controlled Oscillator + miscellaneous blocks 0. 62 mm² 4 Digital and MAC support 0. 60 mm² 5 Digital Dispersive Delay Line (DDDL) for selected maximum chirp duration 0. 32 mm² 6 Chirp generator for selected maximum chirp duration 0. 08 mm² 7 Occupied chip area for all major blocks required to build complete transceiver chip utilizing CSS technology 5. 47 mm² Submission 47 J. Lampe, R. Hach, L. Menzer, Nanotron

January 2005 IEEE-15 -05 -0002 -00 -004 a Unit Manufacturing Complexity • Target process:

January 2005 IEEE-15 -05 -0002 -00 -004 a Unit Manufacturing Complexity • Target process: RF-CMOS, 0. 13 µm feature size Pos. Block description Estimated Area Unit 1 Receiver with high-end LNA 1. 90 mm² 2 Transmitter, Pout = + 10 d. Bm 1. 71 mm² 3 Digitally Controlled Oscillator + miscellaneous blocks 0. 59 mm² 4 Digital and MAC support 0. 38 mm² 5 Digital Dispersive Delay Line (DDDL) for selected maximum chirp duration 0. 21 mm² 6 Chirp generator for selected maximum chirp duration 0. 06 mm² 7 Occupied chip area for all major blocks required to build complete transceiver chip utilizing CSS technology 4. 85 mm² Submission 48 J. Lampe, R. Hach, L. Menzer, Nanotron

January 2005 IEEE-15 -05 -0002 -00 -004 a Summary Chirp Spread Spectrum (CSS) is

January 2005 IEEE-15 -05 -0002 -00 -004 a Summary Chirp Spread Spectrum (CSS) is simple, elegant, efficient • Combines DSSS and UWB strengths • Adds precise location-awareness • Robustness – multipath, interferers, correlation, FEC, 3 channels, CCA • Can be implemented with today’s technologies – Low-complexity – Low-cost – Low power consumption • • • Globally certifiable Scalability with many options for the future Backward compatible with 802. 15. 4 -2003 Mobility enhanced No MAC changes (minimal for ranging) Size and Form Factor – meets or exceeds requirements Excellent throughput SOPs – FD channels Signal Acquisition – excellent Link Budget and Sensitivity – excellent Power Management and Consumption - meets or exceeds requirements Antenna – many good choices Submission 49 J. Lampe, R. Hach, L. Menzer, Nanotron

January 2005 IEEE-15 -05 -0002 -00 -004 a Summary Chirp Spread Spectrum (CSS) Proposal

January 2005 IEEE-15 -05 -0002 -00 -004 a Summary Chirp Spread Spectrum (CSS) Proposal Meets the PAR and 5 C: ü Precision ranging capability accurate to one meter or better ü Extended range over 802. 15. 4 -2003 ü Enhanced robustness over 802. 15. 4 -2003 ü Enhanced mobility over 802. 15. 4 -2003 ü International standard ü Ultra low complexity (comparable to the goals for 802. 15. 4 -2003) ü Ultra low cost (comparable to the goals for 802. 15. 4 -2003) ü Ultra low power consumption (comparable to the goals for 802. 15. 42003) ü Support coexisting networks of sensors, controllers, logistic and peripheral devices in multiple compliant co-located systems. Submission 50 J. Lampe, R. Hach, L. Menzer, Nanotron