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Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs) Submission Title: [FEC and modulations options and proposal for TG4a ] Date Submitted: [30-Sep-2005] Source: [Laurent Ouvry, Samuel Dubouloz] Company [CEA-Leti] Address [17 rue des Martyrs 38054 Grenoble]
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Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs) Submission Title: [FEC and modulations options and proposal for TG4a ] Date Submitted: [30-Sep-2005] Source: [Laurent Ouvry, Samuel Dubouloz] Company [CEA-Leti] Address [17 rue des Martyrs 38054 Grenoble] Voice:[+33-4-38-38-93-88 ], FAX: [+ 33-4-38-38-51-59 ], E−Mail: [laurent.ouvry@cea.fr; samuel.dubouloz@cea.fr] Re: [802.15.4a.] Abstract: [Gives the current FEC and modulation proposals for TG4a] Purpose: [To promote discussion in 802.15.4a.] 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. L. Ouvry, S. Dubouloz, CEA-Leti
Outline • Reference documents • Baseline • What we propose • Simulations L. Ouvry, S. Dubouloz, CEA-Leti
Reference documents to build this one • IEEE.802.15-05-0XXX-0Y-004a • XXXrY (…) • 424r1 (simulation framework) • 389r2 (band plan) • 456r1 and 456r2 (preamble) • 466r0 (amendment to the preamble) • 428r0 (PRF and peak power) • 528r0 (modulation and scrambler structure) • 600r0 (FEC options and their numbering !) L. Ouvry, S. Dubouloz, CEA-Leti
Modulation(from 582r0) L. Ouvry, S. Dubouloz, CEA-Leti
Scrambler example (from 582r0) L. Ouvry, S. Dubouloz, CEA-Leti
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 L. Ouvry, S. Dubouloz, CEA-Leti
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 : base is FEC 5see slide 12 or 600r0 PPM bit (seen by coherent and non coherent receiver) BPSK bit (seen by coherent receiver only) S -S S -S L. Ouvry, S. Dubouloz, CEA-Leti
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 (TBC) 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 L. Ouvry, S. Dubouloz, CEA-Leti
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) L. Ouvry, S. Dubouloz, CEA-Leti
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) L. Ouvry, S. Dubouloz, CEA-Leti
Viterbi 1/3 Convolutional 1/3 Viterbi 1/2 FEC 6 Details Common Rb at PHY SAP + Coder + Modulation Mapping Non Coherent Receiver (only 4-PPM) Non Coherent Receiver (4-PPM + Polarity) L. Ouvry, S. Dubouloz, CEA-Leti
FEC Options (from 600r0) 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 L. Ouvry, S. Dubouloz, CEA-Leti
So what we propose in FEC 6 is: Perfect compatibility between Tx and coherent and non-coherent Rx L. Ouvry, S. Dubouloz, CEA-Leti
Summary of rates (modifed from 600r0) Options we intend to simulate and compare L. Ouvry, S. Dubouloz, CEA-Leti
Simulations under work Options 3, 5 and 6 : • For coherent and non coherent • With soft and hard decisions • With K=3 and 5 Then with : • Scrambling and peak PRFs of 494 & 247 MHz • Checking of spectrum compliance with FCC (thanks to15-05-0354-01-004a-UWB-Power-Measurements.zip) L. Ouvry, S. Dubouloz, CEA-Leti