Nov 2004 doc IEEE 802 15 04 0525

Nov 2004 doc. : IEEE 802. 15 -04 -0525 -02 -004 b Project: IEEE P 802. 15 Working Group for Wireless Personal Area Networks (WPANs) Submission Title: [Proposed Code Sequences for IEEE 802. 15. 4 a Alt-PHY] Date Submitted: [9 Nov, 2004] Source: [Francois Chin, Sam Kwok, Xiaoming Peng, Kannan, Yong- Huat Chew, Chin-Choy Chai, Hongyi Fu, Manjeet, Tung-Chong Wong, T. T. Tjhung, Zhongding Lei, Rahim] Company: [Institute for Infocomm Research, Singapore] Address: [21 Heng Mui Keng Terrace, Singapore 119613] Voice: [65 -68745687] FAX: [65 -67744990] E-Mail: [chinfrancois@i 2 r. a-star. edu. sg] Re: [Response to the call for proposal of IEEE 802. 15. 4 b, Doc Number: 15 -04 -0239 -00 -004 b] Abstract: [This presentation compares all proposals for the IEEE 802. 15. 4 b PHY standard. ] Purpose: [Proposal to IEEE 802. 15. 4 b Task Group] 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 Francois Chin, Institute for Infocomm Research (I 2 R)

Nov 2004 doc. : IEEE 802. 15 -04 -0525 -02 -004 b Proposed Code Sequences for IEEE 802. 15. 4 a Alt-PHY Francois Chin Institute for Infocomm Research Singapore Submission 2 Francois Chin, Institute for Infocomm Research (I 2 R)

Nov 2004 doc. : IEEE 802. 15 -04 -0525 -02 -004 b Proposed System Parameters Chip rate 16 Mcps Pulse Rep. Freq. 16 MHz Symbol Rate 0. 5 MHz Min. info. bit / sym. 4 bit / symbol Max bit rate 4 x 0. 5 = 2. 0 Mbps # Chip / symbol (Code length) 32 #Code Sequences/ piconet 16 (4 bit/symbol) Code position modulation (CPM) Lower bit rate Pulse Repetition Modulation On-Off Keying (OOK) Total # simultaneous piconets supported 6 Multple access for piconets Fixed band sequence for each piconet Submission 3 Francois Chin, Institute for Infocomm Research (I 2 R)

Nov 2004 doc. : IEEE 802. 15 -04 -0525 -02 -004 b UWB Pulse & Spectrum • 1. 5 ns rectified cosine shape • ~1400 MHz 10 -d. B bandwidth • Centre frequency 4 GHz Submission 4 Francois Chin, Institute for Infocomm Research (I 2 R)

Nov 2004 doc. : IEEE 802. 15 -04 -0525 -02 -004 b Code Sequence Set Seq 1 111000110101000010010110011 Seq 2 1011100010101101000011001001111 Seq 3 110111110100101011000011100 Seq 4 010110001111100110100100001 Seq 5 1111001001100001011010100011101 Seq 6 001110000110101001011111011 • 31 -chip M-Sequence set • Only one sequence and one fixed band (no hopping) will be used by all devices in a piconet • Logical channels for support of multiple piconets • 6 sequences = 6 logical channels (e. g. overlapping piconets) Submission 5 Francois Chin, Institute for Infocomm Research (I 2 R)

Nov 2004 doc. : IEEE 802. 15 -04 -0525 -02 -004 b Gray Coded Code Position Modulation (CPM) Symbol Cyclic shift to right by n chips, n= 32 -Chip value To obtain 32 -chip per symbol, cyclic shift first, then extend 1 -chip 0000 0 111000110101000010010110011 1 0001 2 111110001101010000100101100 0 0011 4 001111100011010100001001011 0 0010 6 110011111000110101000010010 1 0110 8 101100111110001101010000100 1 0111 10 001011001111100011010100001 0 0101 12 010010110011111000110101000 0 0100 14 000100101100111110001101010 0 1100 16 100001001011001111100011010 1 1101 18 1010000100101100111110001101110 1 1111 20 1010100001001011001111100011011 1 1110 22 1110101000010010110011111000110 1 1010 24 1011101010000100101100111110001 1 1011 26 011010100001001011001111100 0 1001 28 000110101000010010110011111 0 1000 30 000110101000010010110011111 0 Submission 6 Francois Chin, Institute for Infocomm Research (I 2 R)

Nov 2004 doc. : IEEE 802. 15 -04 -0525 -02 -004 b Cyclic Extended Chip • To avoid / reduce inter-symbol interference in channels with excess delay spread Submission 7 Francois Chin, Institute for Infocomm Research (I 2 R)

Nov 2004 doc. : IEEE 802. 15 -04 -0525 -02 -004 b Properties of M-Sequences • Cyclic auto-correlation of any antipodal sequence gives peak value of 31 and sidelobe value of -1 throughout • Cyclic correlation of any antipodal sequence with its corresponding uni-podal sequence give peak value of 16 and zero sidelobe throughout Submission 8 Francois Chin, Institute for Infocomm Research (I 2 R)

Nov 2004 doc. : IEEE 802. 15 -04 -0525 -02 -004 b Synchronisation Preamble Correlator output for synchronisation • Code sequence has excellent autocorrelation properties • Preamble is constructed by repeating base Code Sequence • Unique – no symbol & spreading combination can construct this preamble • Unlike 15. 4, where preamble is constructed by 8 x ‘ 0000’ symbols Submission 9 Francois Chin, Institute for Infocomm Research (I 2 R)

Nov 2004 doc. : IEEE 802. 15 -04 -0525 -02 -004 b Comparison with other Sequences Say 31 -chip Gold Sequences as follows: Seq 1 101000011110011101101010110 Seq 2 0000011101001001111010 Seq 3 0110101111000000110111000 Seq 4 001001010110110010101100001 Seq 5 0010000111101010001101001001111 Seq 6 110001011011110100011001000 Grey coded CPM is also employed Submission 10 Francois Chin, Institute for Infocomm Research (I 2 R)

Nov 2004 doc. : IEEE 802. 15 -04 -0525 -02 -004 b Comparison with other Sequences • Using square envelop detector, integrate – dump & soft despreading, M-Sequence has better multipath performance in Residential LOS & NLOS than Gold Sequences, by ~1. 5 d. B • CM 2 (NLOS) performance is slightly worst than CM 1 (LOS) Submission 11 Francois Chin, Institute for Infocomm Research (I 2 R)

Nov 2004 doc. : IEEE 802. 15 -04 -0525 -02 -004 b Comparison with other Sequences M-Sequence has better single isolated piconet performance due to its excellent cross correlation between mapping sequences Submission 12 Francois Chin, Institute for Infocomm Research (I 2 R)

Nov 2004 doc. : IEEE 802. 15 -04 -0525 -02 -004 b Inter-Piconet Interference Suppression Let investigate the false alarm probability in the presence of one & two overlapping piconets with asynchronous operation, all piconets using sequences from either M-Sequence Code Set or Gold Sequence Code Set for all piconets False Interference Alarm suppression at Probability corr output (1 interfering piconet) Interference suppression at corr. output (2 interfering piconets) M-Sequence 2. 0 x 10 -3% 15. 0 d. B 11. 8 d. B Gold sequence 1. 2 x 10 -2% 14. 5 d. B 11. 4 d. B M-Sequence Code Set gives lower false alarm probability and better suppression Submission 13 Francois Chin, Institute for Infocomm Research (I 2 R)

Nov 2004 doc. : IEEE 802. 15 -04 -0525 -02 -004 b Summary M-Sequence Codes is recommended for low rate low-power UWB: • Low cyclic auto-correlation • One sequence for the entire piconet for • Better synchronisation / acquisition performance due to low autocorrelation properties; • Simple and robust symbol-to-chip mapping using cyclic shifts; • One code set for simultaneous operating piconets with Good interference suppression capability among the piconets Submission 14 Francois Chin, Institute for Infocomm Research (I 2 R)