1. doc.: IEEE 802.15-<doc#>
<month year>
<month year>
doc.: IEEE <doc#>
doc.: IEEE <doc#>
01/01/2019
Project: IEEE P Working Group for Wireless Personal Area Networks (WPANs)
Submission Title: [ Suggestions for Harmonization of the DSSS PHY]
Date Submitted: [ December 2009 ]
Source: [Michael Schmidt, David Howard, Liang Li,Tae-Joon Park, Seong-Soon Joo, Wun-Cheol Jeong, Jong-Suk Chae, Kuor Hsin Chang, Scott Weikel, Clint Powell, Rick Enns]
Company: [Atmel, On-Ramp Wireless, Vinno/Huawei, ETRI, Elster Electricity, Consultants]
Re: [ TG4g ]
Abstract:
Purpose: Suggestions for Harmonization of the DSSS PHY
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(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
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2. Goals DSSS proposal to meet requirements of TG4g PAR
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Goals
DSSS proposal to meet requirements of TG4g PAR
Support interoperability with 2.4 and sub GHz legacy
Explicit support for NA, Europe, Korea, China
Complement to FSK and OFDM proposals

3. (2) single spreading scheme for (SHR, PHR) (preamble)
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O-QPSK
Modulator
Binary Data
From PSDU
CC ½(1)
Interleaving(1)
DSSS
CA-CDM
(SHR,PHR)
Preamble
DSSS(2)
Notes:
(1) is optional for CA-CDM (Constant Amplitude Code Division Multiplex)
(2) single spreading scheme for (SHR, PHR) (preamble)

4. Agreements Support for 802.15.4-2006 OQPSK for 915 and 2450 MHz
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Agreements
Support for OQPSK for 915 and 2450 MHz
Reference modulator
Outer Forward Error Correction Coding & interleaving (optional for CA-CDM)
Single preamble for .4g modes
Frequency bands and channel plan

5. Further Efforts Harmonization spreading modes Mode selection mechanism
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Further Efforts
Harmonization spreading modes
Mode selection mechanism
Best method to support for OQPSK (915 and 2450 MHz)

6. 01/01/2019
IEEE OQPSK support
OQPSK with RC (raised cosine) shaping only
Nyquist so EVM requirements are not violated
In contrast to half-sine shaping, there are no MSK-like spectral side-lobes addressing issues with 915/2450 MHz IEEE OQPSK signals (reduced ACI, out-of-band emissions at band- edge).
No interoperability issues with legacy devices
Give up GMSK and Pre-coding
Simplify

7. Harmonization of Spreading Modes for legacy and non-legacy Modes
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Harmonization of Spreading Modes for legacy and non-legacy Modes
Pip Attribute called “phy{Name}SpreadingMode” with values “DSSS” or “CA-CDM”
Both non-legacy modes apply the same (SHR, PHR) structure with simple (N,1) spreading
Both non-legacy modes can be distinguished by a dedicated SFD value.
Both SFD values need to be defined
Problems related to IQ images are less relevant due to the PN nature of preamble (see doc #824)

8. Harmonization of Spreading Modes for legacy and non-legacy Modes
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Harmonization of Spreading Modes for legacy and non-legacy Modes

9. DSSS-Non-legacy Modes for 915 MHz
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DSSS-Non-legacy Modes for 915 MHz
Chip Rate: 1000 kchip/s
(SHR,PHR)
(64,1) spreading
PSDU Modes
RateMode
DSSS-Code
½ CC FEC + interleaver
Data rate [kbps]
(16,1)
yes
31.25 1
(16,4)
* Legacy code
125 2
(8,4)
250 3
none
500

10. 01/01/2019
DSSS-Modes for 915 MHz
The (16,4) DSSS code is equivalent to the IEEE legacy O-QPSK code for 915 MHz. So the legacy mode can be enabled by bypassing the CC-FEC and interleaver and prepending the legacy (SHR,PHR) with (16,4) spreading.
Preamble of legacy mode and non-legacy mode can be sensed at the same time since the RF-bandwidth is the same.
The (8,4) code is the code given in doc #738 with optimal Hamming distance of 4 (extended BCH code).

11. CA-CDM-Non-legacy Modes for 915 MHz
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CA-CDM-Non-legacy Modes for 915 MHz
Chip Rate: 1000 kchip/s
(SHR,PHR)
(64,1) spreading
PSDU Modes
RateMode
CA-CDM-Code(TPC+ Hadamard spreading)
½ CC FEC +
Interleaver
Data rate [kbps]
(64,8)
yes
62.5 1
(32,8)
125 2
none
250 3
(16,9)
500(562.5)

12. 01/01/2019
CA-CDM-Modes for 915 MHz
CA-CDM is composed of (4,3)x(4,3) TPC (Turbo Product Code) and Hadamard spreader
(4,3)x(4,3) TPC
The horizontal code is the first order Reed-Muller code (Hadamard code).
The vertical code is the odd parity check code.
Iterative decoding can be employed to enhance the code performance.
High spreading gain.
CA-CDM-Code
(4,3)x(4,3) TPC
Minimum Distance
Spreading gain (dB)
Data rate [kbps]
(64,8) 4
12.0
62.5
(32,8)
9.0
250 / 125
(16,9)
6.0
500(562.5)

13. DSSS-Non-legacy Modes for 2450 MHz
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DSSS-Non-legacy Modes for 2450 MHz
Chip Rate: kchip/s
(SHR,PHR)
(64,1) (128,1) spreading
PSDU Modes
RateMode
DSSS-Code
½ CC FEC + interleaver
Data rate [kbps]
(16,1) (32,1)
yes
31.25 1
(16,4) (32,4)
* Legacy code
125 2
(8,4) (16,4)
250 3
none (8,4)
500

14. 01/01/2019
DSSS-Modes for 2450 MHz
The (32,4) DSSS code is equivalent to the IEEE legacy O-QPSK code for 2450 MHz. So the legacy mode can be turned on by bypassing FEC and interleaver and prepending the legacy (SHR,PHR) with (32,4) spreading.
Preamble of legacy mode and non-legacy mode for this band can be sensed at the same time since the RF-bandwidth is the same.
The (16,4) code is the legacy code of 915 MHz.
The (8,4) code is the code given in doc #738 with optimal Hamming distance of 4 (extended BCH code).
Performance simulations of the non-legacy DSSS modes showed similar results for 915 MHz and 2450 MHz (AWGN, ITU-B) for a given RateMode.

15. CA-CDM-Modes for 2450 MHz Chip Rate: 2000 kchip/s (SHR,PHR)
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CA-CDM-Modes for 2450 MHz
Chip Rate: 2000 kchip/s
(SHR,PHR)
(128,1) spreading
PSDU Modes
RateMode
CA-CDM-Code(TPC+ Hadamard spreading)
½ CC FEC + interleaver
Data rate [kbps]
(128,8)
yes
62.5 1
(64,8)
125 2
none
250 3
(32,9)
500(562.5)

16. 01/01/2019
CA-CDM-Modes for 2450 MHz
CA-CDM is composed of (4,3)x(4,3) TPC (Turbo Product Code) and Hadamard spreader
(4,3)x(4,3) TPC
The horizontal code is the first order Reed-Muller code (Hadamard code).
The vertical code is the odd parity check code.
Iterative decoding can be employed to enhance the code performance.
High spreading gain.
CA-CDM-Code
(4,3)x(4,3) TPC
Minimum Distance
Spreading gain (dB)
Data rate [kbps]
(128,8) 4
15.0
62.5
(64,8)
12.0
250 / 125
(32,9)
9.0
500(562.5)

17. 01/01/2019
Name of the PHY
The name “SUN-DSSS PHY” is not appropriate for various reasons:
This PHY is a multi-rate PHY supporting various data rate by different spreading modes.
We have “DSSS” spreading, “CA-CDM” spreading or no spreading at all (e.g. refer to DSSS 915MHz mode 3 – 500kbps).
Spreading is not unique for this PHY, since it is also utilized by the OFDM PHY (frequency spreading).
“SUN” might be problematic with SUN micro systems.
A suggested name is MR-OQPSK PHY. This is in accordance with
the name "MR-FSK PHY“ (MR = Multi Rate).