doc.: IEEE 802.15-<doc#> <month year> doc.: IEEE 802.15-<doc#> Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs) Submission Title: [Merged DSSS Proposal for TG4g] Date Submitted: [September 18, 2009] Source: [Kuor Hsin Chang, Scott Weikel, Clint Powell, & Rick Enns, Seong-Soon Joo, Tae-Joon Park, Wun-Cheol Jeong, Jong-Suk Chae] Company: [Elster Electricity, Consultants, ETRI] Address: [] Voice: [KC:+1.919.901.2377, SW:+1.919.212.4866, CP:+1.480.586.8457, RE:+1.650.327.9708, SSJ: +82-42-860-6333, TJP: +82-42-860-6902, WCJ: +82-42-860-5104, JSC: +82-42-860-6480] E-Mail:[kuor-hsin.chang@us.elster.com, scott.j.weikel@us.elster.com, cpowell@ieee.org, enns@stanfordalumni.org, ssjoo@etri.re.kr, tjpark@etri.re.kr, wjeong@etri.re.kr, jschae@etri.re.kr] Re: [] Abstract: Merged Proposal for a 802.15.4 radio based on a flexible DSSS Purpose: Presented to the 802.15.4g SUN Task Group for consideration 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. <author>, <company>

Merged Proposal for DSSS to TG4g <month year> doc.: IEEE 802.15-<doc#> Merged Proposal for DSSS to TG4g Merged proposals : 09-295, 09-301 Kuor Hsin Chang1 , Scott Weikel1 Clint Powell2, Rick Enns2 Seong-Soon Joo3 , Tae-Joon Park3, Wun-Cheol Jeong3, Jong-Suk Chae3 Elster Electricity1, Consultant2, ETRI3 <author>, <company>

doc.: IEEE 802.15-<doc .....> <May,2009> doc.: IEEE 802.15-<doc .....> Agenda Motivation Proposed Solution Flexible DSSS for 2.4GHz Flexible DSSS for 900MHz PPDU Format Benefits Compliance to the PAR Benefits of Flexible DSSS Summary and conclusions <author>, <company>

Motivation Maintain compatibility to the legacy devices Extend the existing 802.15.4-2006 PHY to serve the application in SUN network Improve the existing 802.15.4-2006 PHY for outdoor communications Keep principle of simple, low cost, low energy

Flexible DSSS for 2.4GHz (1) Provide configuration options for the number of chips per symbol and bits per symbol while keeping the chip rate constant at 1Mcps/2Mcps Optimize performance for range and data rate – long range at reduced data rate and short range at high data rate

Flexible DSSS for 2.4 GHz (2) Chip rate (cps) Chips per symbol Bits per symbol Data rate (bps) Coding gain (dB) Notes 2 M 32 1 62.5 K* 15.05 rural application 2 125 K* 12.04 4 250 K 9.03 16 500 K 6.02 Urban application * Under Review

PN Codes & Chip to Symbol Mapping: Data Rate of 62.5 kbps Data Rate of 125 kbps Data Rate of 250 kbps (2.4 GHz PHY in IEEE 802.15.4-2006) Data symbol (decimal) (binary) (b0) Chip values (c0 c1 … c30 c331) Note 1 1 0 1 1 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 0 PN Code 0 in Table 24 1 1 0 0 0 1 1 0 0 1 0 0 1 0 1 1 0 0 0 0 0 0 1 1 1 0 1 1 1 1 0 1 1 PN Code 8 in Table 24 Data symbol (decimal) (binary) (b0 b1) Chip values (c0 c1 … c30 c331) Note 00 1 1 0 1 1 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 0 PN Code 0 in Table 24 1 10 0 1 0 1 0 0 1 0 0 0 1 0 1 1 1 0 1 1 0 1 1 0 0 1 1 1 0 0 0 0 1 1 PN Code 4 in Table 24 2 01 1 0 0 0 1 1 0 0 1 0 0 1 0 1 1 0 0 0 0 0 0 1 1 1 0 1 1 1 1 0 1 1 PN Code 8 in Table 24 3 11 0 0 0 0 0 1 1 1 0 1 1 1 1 0 1 1 1 0 0 0 1 1 0 0 1 0 0 1 0 1 1 0 PN Code 12 in Table 24

PN Codes & Chip to Symbol Mapping (cont’d.) Data Rate of 500 kbps Data symbol (decimal) (b0 b1 b2 b3) Chip values (c0 c1 … c14 c15) 0 0 0 0 0 0 1 1 1 1 1 0 0 0 1 0 0 1 0 1 1 1 0 0 0 0 1 0 0 1 1 1 1 1 0 0 0 1 0 0 1 2 0 1 0 0 0 1 0 1 0 0 1 1 1 1 1 0 0 0 1 0 3 1 1 0 0 1 0 0 1 0 1 0 0 1 1 1 1 1 0 0 0 4 0 0 1 0 0 0 1 0 0 1 0 1 0 0 1 1 1 1 1 0 5 1 0 1 0 1 0 0 0 1 0 0 1 0 1 0 0 1 1 1 1 6 0 1 1 0 1 1 1 0 0 0 1 0 0 1 0 1 0 0 1 1 7 1 1 1 0 1 1 1 1 1 0 0 0 1 0 0 1 0 1 0 0 8 0 0 0 1 0 1 1 0 1 0 1 1 0 1 1 1 0 0 0 0 9 1 0 0 1 0 0 0 1 1 0 1 0 1 1 0 1 1 1 0 0 10 0 1 0 1 0 0 0 0 0 1 1 0 1 0 1 1 0 1 1 1 11 1 1 0 1 1 1 0 0 0 0 0 1 1 0 1 0 1 1 0 1 12 0 0 1 1 0 1 1 1 0 0 0 0 0 1 1 0 1 0 1 1 13 1 0 1 1 1 1 0 1 1 1 0 0 0 0 0 1 1 0 1 0 14 0 1 1 1 1 0 1 1 0 1 1 1 0 0 0 0 0 1 1 0 15 1 1 1 1 1 0 1 0 1 1 0 1 1 1 0 0 0 0 0 1

Flexible DSSS for 900MHz (1) Improve the existing 802.15.4-2006 PHY for outdoor communications Simple and reasonable approach to combat multipath fading Adopt Constant Amplitude - Code Division Multiplex (CA-CDM)

Flexible DSSS for 900 MHz (2) Chip rate (cps) Chips per symbol Bits per symbol Data rate (bps) Symbol duration Notes 1 M 128 9 62.5 K (70.3K) 128us rural application 64 125 K (140.6K) 64us 16 4 250 K 16us IEEE802.15.4 500 K (562.5K) Urban application

Spreading sequence for 64 chips per symbol (125/62.5 Kbps) Data symbol (decimal) (binary) (b0) Chip values (c0 c1 … c30 c331) Note 1 1 1 0 1 1 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 0 1 0 0 0 1 1 0 0 1 0 0 1 0 1 1 0 0 0 0 0 0 1 1 1 0 1 1 1 1 0 1 1 PN Code 0/8 in Table 24 Data Rate of 250 kbps (900 MHz PHY in IEEE 802.15.4-2006) Spreading sequence for 16 chips per symbol(500Kbps) Data symbol (decimal) (b0 b1 b2 b3) Chip values (c0 c1 … c14 c15) Note 0 0 0 0 0 0 1 1 1 1 1 0 0 0 1 0 0 1 0 1 PN Code 0 in Table 37 ∙

PPDU Format Proposal Extend the Frame Length Field (PHR) of 802.15.4 packet from one byte to two bytes in order to support the packet length to be up to 1500 bytes. Use bit 15 (bit 7 of the Frame Control Field) of the PHR to determine long packet (≥127 bytes) or short packet (≤127 bytes)

Packet Length Field Maximum packet length of 2047 bytes. Use Bit 11-12 to determine data rate: Bit 11-12 00 01 10 11 Data Rate (k bps) 62.5 125 250 500

Packet Length Field (cont’d.) Bit 13: Parity Check bit for packet length to avoid unnecessary receiver power consumption due to errors in packet length Bit 15: 0: Short Packet (Packet Length to be ≤ 127 bytes) 1: Long Packet (127 bytes < Packet Length ≤ 2047 bytes)

Compliance to the PAR PAR requirement Comments Operation in license exempt bands  DSSS can be applied to the radios for the 868/915/2.4 GHz bands Data rate between 40 and 1,000 kbps Adjustable data rates available in this range Optimal link margins for rural and urban environments Coding trades off data rate for range Principally outdoor Basic radio proven 1500 octet frame size An extension to the radio synchronization At least 3 co-located networks Supported At least 1,000 neighbors

Advantages of Making DSSS Flexible (1) Easy chip design – keeps the chip rate set at what 802.15.4-2006 uses. The design of the front end of the current chips can be used. Simple- we know the radio and this is well understood extension to only the digital side. Known coexistence properties – transmissions look the same to other radios.

Advantages of Making DSSS Flexible (2) Mitigating the requirements for Power amplifier by reducing PAPR Minimizing the performance loss due to the two-level conversion by exploiting odd-parity check encoded data Long symbol duration (code (128,9))

Conclusions Merged proposal for flexible DSSS Compatible to the existing 802.15.4-2006 PHY Easy chip design – keeps the chip rate set at what 802.15.4-2006 uses. Simple and reasonable solution for multipath fading

Backup

CA-CDM Transmitter Block diagram of CA-CDM Transmitter

CA-CDM Transmitter Odd-Parity Check Code Encoder

CA-CDM Transmitter Hadamard Modulation (Reed-Muller Encoding) Symbol mapping

CA-CDM Transmitter (16,4) Hadamard Spreading

CA-CDM Transmitter Bitwise XOR

CA-CDM Receiver CA-CDM Receiver Block Diagram

62.5Kbps Simulation results in AWGN channel CA-CDM in AWGN channel (32,1) in AWGN channel

62.5Kbps Simulation results in Rayleigh channel CA-CDM in Rayleigh channel (32,1) in Rayleigh channel

Summary of simulation results In AWGN channel condition CA-CDM shows 4.5 dB of improvement comparing to IEEE802.15.4-2006 with (32,1) code In Rayleigh Fading channel condition CA-CDM shows 4.8 dB of improvement comparing to IEEE802.15.4-2006 with (32,1) code