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Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANS) Submission Title: [Staccato UWB PHY Proposal for TG4a] Date Submitted:

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Presentation on theme: "Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANS) Submission Title: [Staccato UWB PHY Proposal for TG4a] Date Submitted:"— Presentation transcript:

1 Project: IEEE P Working Group for Wireless Personal Area Networks (WPANS) Submission Title: [Staccato UWB PHY Proposal for TG4a] Date Submitted: [January 2005] Revised: [] Source: [Roberto Aiello, Ph.D., Torbjorn Larsson, Ph.D.] Company [Staccato Communications] Re: [ a Call for proposal] Abstract: [This presentation represents Staccato Communications proposal for the a PHY standard, based on UWB] Purpose: [Response to WPAN a Call for Proposals] Notice: This document has been prepared to assist the IEEE P It is offered as a basis for discussion and is not binding on the contributing individual or organization. The material in this document is subject to change in form and content after further study. The contributor reserves 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 January 2005 doc.: IEEE /xxxr0

2 doc.: IEEE /704r0 Submission January 2005 Roberto Aiello, Staccato CommunicationsSlide 2 Staccato Communications UWB PHY Proposal for TG4a Roberto Aiello, Ph.D. Torbjorn Larsson, Ph.D. Staccato Communications

3 doc.: IEEE /704r0 Submission January 2005 Roberto Aiello, Staccato CommunicationsSlide 3 Goals Good use of UWB unlicensed spectrum Good system design Path to low complexity CMOS design Path to low power consumption Scalable to future standards Graceful co-existence with other services Graceful co-existence with other UWB systems

4 doc.: IEEE /704r0 Submission January 2005 Roberto Aiello, Staccato CommunicationsSlide 4 Introduction Staccato is MBOAs founding member, promoter BOD member This proposal is based on band limited impulse radio OFDM is optimal solution for high performance systems Impulse radio has attractive features for 15.4a applications

5 doc.: IEEE /704r0 Submission January 2005 Roberto Aiello, Staccato CommunicationsSlide 5 Features Meet all system requirements Low signal repetition frequency to reduce ISI and need for high speed digital circuits (lower power consumption) Narrow UWB bandwidth to reduce complexity

6 doc.: IEEE /704r0 Submission January 2005 Roberto Aiello, Staccato CommunicationsSlide 6 Summary Band limited UWB system Compliant with FCC 02-48, UWB Report & Order 4.752GHz, 5.252GHz center frequency, 500MHz bandwidth at -10dB Varies symbol rate, from 12.5kbps to 1.6Mbps at PHY-SAP Due to time constraints this presentation addresses –Modulation scheme –Performance in AWGN channel Remaining material will be presented at the next opportunity in March 2005 –Performance in multipath –Channelization –Implementation feasibility –Self evaluation criteria –Other issues that will emerge from groups feedback

7 doc.: IEEE /704r0 Submission January 2005 Roberto Aiello, Staccato CommunicationsSlide 7 FCC compliant FCC compliant according to FCC UWB R&O In this proposal the transmit signal occupies 500MHz at all times: frequency change is used to reduce ISI, not to spread the spectrum Thus, as long as the transmission system complies with the fractional bandwidth or minimum bandwidth requirements at all times during its transmission, we agree that it should be permitted to operate under the UWB regulations. [FCC UWB R&O, B-32]

8 doc.: IEEE /704r0 Submission January 2005 Roberto Aiello, Staccato CommunicationsSlide 8 System description code length longer than 16 is required to define a reasonable number of codes with good cross- correlation properties different piconets use different spreading codes PRF (chip rate), 3.2 MHz is fairly high –Disadvantages some impact of interchip interference with channel model 8 (industrial NLOS), –Advantages it allows use of rate 1/2 coding at 100 kbps (we consider this one of the most important data rates) It also allows implementation without frequency offset correction (with some performance loss) it removes the need for frequency offset correction during acquisition, which leads to faster acquisition and a shorter preamble After acquisition, frequency offset correction can be switched on to improve the performance If the frequency offset estimate is good enough, it is possible to use partially coherent detection (with a coherent integration interval equal to the spreading code duration) instead of differential detection for further improved performance. Pulse shape: 3rd-order Butterworth FEC: 16-state convolutional code, with optional puncturing.

9 doc.: IEEE /704r0 Submission January 2005 Roberto Aiello, Staccato CommunicationsSlide 9 Packet structure

10 doc.: IEEE /704r0 Submission January 2005 Roberto Aiello, Staccato CommunicationsSlide 10 Spreading codes Spreading codes of length 16 with minimal autocorrelation and cross-correlation, essential for acquisition, were found

11 doc.: IEEE /704r0 Submission January 2005 Roberto Aiello, Staccato CommunicationsSlide 11 Throughput The length of the data PSDU (payload) is 32 octets. The data rate is 100 kbps (this is X0 in this proposal) Assumptions (refer to the figure on page 20 in the PHY selection criteria document) –aMinLIFSPeriod = 40 symbol periods –aTurnaroundTime = 12 symbol periods –aUnitBackoffPeriod = 20 symbol periods –Length of ACK PSDU = 5 octets t_ack is the time between the end of the data frame and the beginning of the ACK frame –worst case, is t_ack = aTurnaroundTime + aUnitBackoffPeriod = 32 –best case, t_ack is t_ack = aTurnaroundTime = 12

12 doc.: IEEE /704r0 Submission January 2005 Roberto Aiello, Staccato CommunicationsSlide 12 Transceiver architecture (digital) differential detection for acquisition and non-coherent demodulation for data demodulation differential detection for both acquisition and data demodulation A. B.

13 doc.: IEEE /704r0 Submission January 2005 Roberto Aiello, Staccato CommunicationsSlide 13 More on receiver acquisition is based on differential detection, which allows shorter preamble both differential and non-coherent detection are carried out separately for the different multipath components Architecture A. differential detection for both acquisition and data demodulation. Architecture B. differential detection for acquisition non-coherent demodulation (with coherent combining across one codeword) for data demodulation requires frequency offset estimation (during acquisition) and correction (during data demodulation) –differential detection without frequency offset correction. This is possible since the maximum frequency offset is roughly 220 kHz, which leads to a phase shift of / *360 = 25 degrees across one chip period. –differential detection with frequency correction (after acquisition). This will remove the 25 degrees phase shift, leading to some performance improvement. –non-coherent demodulation (with coherent combining across one codeword), which requires frequency offset correction. This should lead to a significant performance improvement, since we are now summing energy coherently across a whole codeword (which for data rates <= 100 kbps is 16 chips long).

14 doc.: IEEE /704r0 Submission January 2005 Roberto Aiello, Staccato CommunicationsSlide 14 Differential combining

15 doc.: IEEE /704r0 Submission January 2005 Roberto Aiello, Staccato CommunicationsSlide 15 Alternative analog transceiver architecture Minimum receiver configuration Potential sub-optimal performance Potential low cost and power implementation

16 doc.: IEEE /704r0 Submission January 2005 Roberto Aiello, Staccato CommunicationsSlide 16 Link budget

17 doc.: IEEE /704r0 Submission January 2005 Roberto Aiello, Staccato CommunicationsSlide 17 System simulation parameters Frequency band: 4.752GHz, GHz (MB-OFDM band 4) 10 dB bandwidth: 500 MHz Transmit power: dBm Transmit filter: 3rd order Butterworth, corner frequency 180 kHz Receive filter: 3rd order Butterworth, corner frequency 160 kHz A/D converter: 528 MHz, 3 bits Noise figure: 7 dB Data rate: 100 kbps PSDU size: 32 bytes PRF (chip rate): 3.2 MHz Length of DS spreading code: 16 Length of preamble: 48 bits Length of SFD: 32 bits Length of PHR: 48 bits Modulation: DBPSK Demodulation method: differential detection No frequency offset

18 doc.: IEEE /704r0 Submission January 2005 Roberto Aiello, Staccato CommunicationsSlide 18 PER vs. distance

19 doc.: IEEE /704r0 Submission January 2005 Roberto Aiello, Staccato CommunicationsSlide 19 PER vs. Eb/No

20 doc.: IEEE /704r0 Submission January 2005 Roberto Aiello, Staccato CommunicationsSlide 20 PER vs. received power

21 doc.: IEEE /704r0 Submission January 2005 Roberto Aiello, Staccato CommunicationsSlide 21 Conclusions UWB band limited system Meet all system requirements Low signal repetition frequency to reduce ISI and need for high speed digital circuits (lower power consumption) Narrow UWB bandwidth to reduce complexity Remaining material will be presented at the next opportunity

22 doc.: IEEE /704r0 Submission January 2005 Roberto Aiello, Staccato CommunicationsSlide 22 Staccato Communications is actively collaborating with others Objectives: Best Technical Solution ONE Solution Excellent Business Terms Fast Time To Market We encourage participation by any party who can help us reach our goals a Early Merge Work


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