doc.: IEEE 802.15-<doc#> <month year> doc.: IEEE 802.15-<doc#> Jan 2005 Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs) Submission Title: [Proposed Code Sequences for IEEE 802.15.4a Alt-PHY] Date Submitted: [Jan 2005] 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@i2r.a-star.edu.sg] Re: [Response to the call for proposal of IEEE 802.15.4a, Doc Number: 15-04-0380-02-004a ] Abstract: [I2R’s Proposal to IEEE 802.15.4a Task Group] Purpose: [For presentation and consideration by the IEEE802.15.4a committee] 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. Francois Chin, Institute for Infocomm Research (I2R) <author>, <company>

doc.: IEEE 802.15-<doc#> <month year> doc.: IEEE 802.15-<doc#> Jan 2005 Proposed Code Sequences, Modulation & Coding for IEEE 802.15.4a Alt-PHY Francois Chin Institute for Infocomm Research Singapore Francois Chin, Institute for Infocomm Research (I2R) <author>, <company>

Jan 2005 Proposal Motivation To satisfy IEEE 802.15.4a technical requirements, low power consumption is crucial Conventional coherent UWB system based on correlator in the receiver can provide fairly good performance, but at the expense of implementation complexity, and consequently power consumption and system cost To meet low power and low cost requirement, UWB system with OOK (On-Off Keying) modulation and noncoherent detection is proposed In the proposed UWB OOK system, the signal demodulation is performed by simply integrating signal energy, thus omitting signal / pulse generator, significantly relieve the strict synchronization requirement and greatly simplify transceiver structure with the minimal power and cost demand However, some challenges of such OOK system are threshold setting, simultaneous operating piconets (SOP) & timing boundaries estimation This proposal contains techniques that will overcome such limitation, and improve the overall system performance of the UWB OOK system Francois Chin, Institute for Infocomm Research (I2R)

doc.: IEEE 802.15-<doc#> <month year> doc.: IEEE 802.15-<doc#> Jan 2005 Proposed System Parameters Chip rate 11 Mcps ** # Pulse / Chip Period 12 Pulse Rep. Freq. 11 x 12 MHz = 132 MHz # Chip / symbol (Code length) 32 Symbol Rate 11/32 MHz = 343.75 kHz Min. info. bit / sym. 4 bit / symbol Max bit rate 4 x 343.75 kHz = 1.375 Mbps Mandatory bit rate 1.375 Mbps / 5 (x Symbol Repetition) = 275kbps #Code Sequences/ piconet 16 (4 bit/symbol) Code position modulation (CPM) Lower bit rate scalability Symbol Repetition Modulation / Demodulation Ternary {+1,-1,0} pulse train / On-Off Keying (OOK) Total # simultaneous piconets supported 6 Multple access for piconets Fixed sequence for each piconet ** Proposed chip rate of 11 MHz is a common denominator in the clock rate of 11a/b/g, MB-OFDM and DS-UWB Francois Chin, Institute for Infocomm Research (I2R) <author>, <company>

doc.: IEEE 802.15-<doc#> <month year> doc.: IEEE 802.15-<doc#> Jan 2005 UWB Pulse & Spectrum 1.5 ns rectified cosine shape ~1400 MHz 10-dB bandwidth Centre frequency ~4 GHz Francois Chin, Institute for Infocomm Research (I2R) <author>, <company>

Modulation & Coding Jan 2005 Binary data From PPDU Bit-to- Symbol Scrambling {+1,-1} Sequence {0,1} Sequence Bit-to- Symbol Symbol- to-Chip Chip Repetition Chip Scrambler Pulse Generator {0,+1,-1} Sequence Bit to symbol mapping: group every 4 bits into a symbol Symbol-to-chip mapping: Each symbol is mapped to a 32-chip {0,1} sequence, according to Gray Coded Code Position Modulation (CPM) Chip Repetition (11 Mcps): Factor of K=5 corresponds to 275 kbps (Mandatory Mode) Chip Scrambling (11 Mcps): the K x 32-chip {0,1} sequence is mutliplied with random scrambing {+1,-1} sequence this is to avoid spectral spikes Pulse Generator (11 x 12 = 132 MHz): Chips are repetited and Ternary -modulated chip = ‘+1'  12 +ve pulse are transmitted @ 132 MHz chip = ‘-1'  12 -ve pulse are transmitted @ 132 MHz chip = '0'  no pulse Francois Chin, Institute for Infocomm Research (I2R)

Multiple access Multiple access within piconet: same as 15.4. Jan 2005 Multiple access Multiple access within piconet: same as 15.4. Multiple access across piconets: CDMA. Different Piconet uses different Base Sequence Francois Chin, Institute for Infocomm Research (I2R)

doc.: IEEE 802.15-<doc#> <month year> doc.: IEEE 802.15-<doc#> Jan 2005 Base Sequence Set Seq 1 1 1 1 0 0 0 1 1 0 1 1 1 0 1 0 1 0 0 0 0 1 0 0 1 0 1 1 0 0 1 1 Seq 2 1 0 1 1 1 0 0 0 1 0 1 0 1 1 0 1 0 0 0 0 1 1 0 0 1 0 0 1 1 1 1 Seq 3 1 1 0 1 1 1 1 1 0 1 0 0 0 1 0 0 1 0 1 0 1 1 0 0 0 0 1 1 1 0 0 Seq 4 0 1 0 1 1 1 0 1 1 0 0 0 1 1 1 1 1 0 0 1 1 0 1 0 0 1 0 0 0 0 1 Seq 5 1 1 1 1 0 0 1 0 0 1 1 0 0 0 0 1 0 1 1 0 1 0 1 0 0 0 1 1 1 0 1 Seq 6 0 0 1 1 1 0 0 0 0 1 1 0 1 0 1 0 0 1 0 0 0 1 0 1 1 1 1 1 0 1 1 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) The same base sequence will be used to construct the symbol-to-chip mapping table Francois Chin, Institute for Infocomm Research (I2R) <author>, <company>

doc.: IEEE 802.15-<doc#> <month year> doc.: IEEE 802.15-<doc#> Jan 2005 Symbol-to-Chip Mapping: Gray Coded Code Position Modulation (CPM) Symbol Cyclic shift to right by n chips, n= 32-Chip value 0000 1 1 1 0 0 0 1 1 0 1 1 1 0 1 0 1 0 0 0 0 1 0 0 1 0 1 1 0 0 1 1 1 0001 2 1 1 1 1 1 0 0 0 1 1 0 1 1 1 0 1 0 1 0 0 0 0 1 0 0 1 0 1 1 0 0 1 0011 4 0 0 1 1 1 1 1 0 0 0 1 1 0 1 1 1 0 1 0 1 0 0 0 0 1 0 0 1 0 1 1 0 0010 6 1 1 0 0 1 1 1 1 1 0 0 0 1 1 0 1 1 1 0 1 0 1 0 0 0 0 1 0 0 1 0 1 0110 8 1 0 1 1 0 0 1 1 1 1 1 0 0 0 1 1 0 1 1 1 0 1 0 1 0 0 0 0 1 0 0 1 0111 10 0 0 1 0 1 1 0 0 1 1 1 1 1 0 0 0 1 1 0 1 1 1 0 1 0 1 0 0 0 0 1 0 0101 12 0 1 0 0 1 0 1 1 0 0 1 1 1 1 1 0 0 0 1 1 0 1 1 1 0 1 0 1 0 0 0 0 0100 14 0 0 0 1 0 0 1 0 1 1 0 0 1 1 1 1 1 0 0 0 1 1 0 1 1 1 0 1 0 1 0 0 1100 16 1 0 0 0 0 1 0 0 1 0 1 1 0 0 1 1 1 1 1 0 0 0 1 1 0 1 1 1 0 1 0 1 1101 18 1 0 1 0 0 0 0 1 0 0 1 0 1 1 0 0 1 1 1 1 1 0 0 0 1 1 0 1 1 1 0 1 1111 20 1 0 1 0 1 0 0 0 0 1 0 0 1 0 1 1 0 0 1 1 1 1 1 0 0 0 1 1 0 1 1 1 1110 22 1 1 1 0 1 0 1 0 0 0 0 1 0 0 1 0 1 1 0 0 1 1 1 1 1 0 0 0 1 1 0 1 1010 24 1 0 1 1 1 0 1 0 1 0 0 0 0 1 0 0 1 0 1 1 0 0 1 1 1 1 1 0 0 0 1 1 1011 26 0 1 1 0 1 1 1 0 1 0 1 0 0 0 0 1 0 0 1 0 1 1 0 0 1 1 1 1 1 0 0 0 1001 28 0 0 0 1 1 0 1 1 1 0 1 0 1 0 0 0 0 1 0 0 1 0 1 1 0 0 1 1 1 1 1 0 1000 30 1 1 0 0 0 1 1 0 1 1 1 0 1 0 1 0 0 0 0 1 0 0 1 0 1 1 0 0 1 1 1 1 To obtain 32-chip per symbol, cyclic shift the Base Sequence first, then extend 1-chip Base Sequence #1 Francois Chin, Institute for Infocomm Research (I2R) <author>, <company>

doc.: IEEE 802.15-<doc#> <month year> doc.: IEEE 802.15-<doc#> Jan 2005 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 correlation with other 15 uni-podal sequences with give zero sidelobe throughout i.e. Each transmit OOK sequence will give a peak correlator output at a correlator with its corresponding antipodal sequence & ZERO at other 15 correlators Francois Chin, Institute for Infocomm Research (I2R) <author>, <company>

doc.: IEEE 802.15-<doc#> <month year> doc.: IEEE 802.15-<doc#> Jan 2005 Cyclic Extended Chip To avoid / reduce inter-symbol interference in channels with excess delay spread To ensure zero inter-chip interference in receiver correlator output Francois Chin, Institute for Infocomm Research (I2R) <author>, <company>

doc.: IEEE 802.15-<doc#> <month year> doc.: IEEE 802.15-<doc#> Jan 2005 Synchronisation Preamble Correlator output for synchronisation Code sequences has excellent autocorrelation properties Preamble is constructed by repeating Sequence ‘0000’ Francois Chin, Institute for Infocomm Research (I2R) <author>, <company>

The transmitter Guide Line : Keep it Simple Jan 2005 The transmitter Guide Line : Keep it Simple Main Goal : "Low cost & low consumption" Pulses are generated in baseband No mixer, no VCO but pulse shaping Simple control logic and "reasonable" clock frequency (Crystal) PSDU Data Clock F = 132MHz Control Logic BaseBand signal RF Signal Pulse Generator PA (option) Pulse shaper Francois Chin, Institute for Infocomm Research (I2R)

Jan 2005 The receiver Fc=5.5MHz BPF ( )2 LPF ADC Soft Despread Energy detection technique rather than coherent receiver, for relaxed synchronization constraints Soft chip values gives best results Oversampling & sequence correlation is used to recovery chip timing recovery Synchronization fully re-acquired for each new packet received (=> no very accurate timebase needed) Low cost, low complexity 22 MHz Sample Rate Francois Chin, Institute for Infocomm Research (I2R)

doc.: IEEE 802.15-<doc#> <month year> doc.: IEEE 802.15-<doc#> Jan 2005 Frame Format Octets: 2 1 0/4/8 n 2 MAC Sublayer Frame Cont. Data Payload Seq. # Address CRC MHR MSDU MFR Octets: TBD 1 1 Data: 32 (n=23) For ACK: 5 (n=0) PHY Layer Frame Length Preamble SFD MPDU SHR PHR PSDU PPDU Francois Chin, Institute for Infocomm Research (I2R) <author>, <company>