1. Joint DSSS Proposal for 802.15.4g
Merged proposal : , ,
1Michael Schmidt, 2Y X Fu, 2J Shen, 2X Wang, 2Haituo Liu, 2L Li, 2Z Zhao, 2Z.F Zhao, 3Ted Myers, 3David Howard
1Atmel, 2Huawei/SIMIT/VINNO, 3On-Ramp Wireless

2. Bands included No bandwidth limitation in bands 780MHz (China)
868MHz (EU)
863 – 870 MHz
915MHz (US)
902 – 928 MHz
2450MHz (Intl)
2400 – MHz

3. DSSS benefits
Better sensitivity increases range for hard to reach meters and challenging environments, especially in-building
Good complement to Merge FSK Proposal
Trade-off between processing gain and data rate with fixed bandwidth – long range for reduced data rate and short range for high data rate
Different data rates can be obtained by simply changing the spreading gain, with same RF design

4. Merged proposal Atmel/Huawei/OnRamp/SIMIT/VINNO
Summary parameters
Merged proposal Atmel/Huawei/OnRamp/SIMIT/VINNO
Frequency
MHz
MHz
900MHz/ 2.4GHz
PSDU Format
8 octets
SFD
SFD: 8 bits
PHR
Date rate: 2 bits
Frame Length: 11 bits
Reserved: 2bits
Parity Check: 1bit
PSDU: octets
SFD Content
0xE5
Spreading factor
1/2/4/8
8/16/32/128
PSDU Date Rate(kbps)
200/100/50/25
500/250/125/62.5
125/62.5/31.2/7.8
Modulation
OQPSK/precoded GMSK (p/2 BPSK)
Channel Code
1/2 rate Convolutional code
Shape
Raised Cosine (OQPSK)/ Gaussian Pulse (GMSK)
Chip rate
200kchip/s
500kchip/s
1Mchip/s
Channel Spacing
400kHz
1MHz
200/400kHz
Sprading Factor (Code)
128
(128,1) 64 32
(32,1) 16
(16,1) 8
(32,4)
(32,4) 15.4 (8,1)? 4
(16,4) 2
(8,4) 1
(4,4)
CRC
CRC-32

5. Modulation O-QPSK GMSK Raised cosine shape r=0.8 Pre-coded
Equivalent to p/2 – BPSK (*)
(*) for example see: Draft P c/DF3, page 45: "a) The standard supports the use of MSK/GMSK modulations with appropriate filtering and pre-coding as an alternative way of generating π/2 BPSK waveform signals for the SC PHY mode."

6. Channel Code ½ rate convolution code Benefits Interleaver Complexity
Supports long frame requirements in PAR
Provides larger gain compared to spreading as decrease data rate by ½
Used in IS-95 and other systems
Consider interleave to improve resistance to burst interference
Interleaver
Max depth of 32 information octets
Complexity
Constraint length k=7

7. 779 – 787 MHz PHY Chip rate = 500kcps Channel center frequency (MHz)
779.5, 780.5, 781.5, 782.5, 783.5, 784.5, 785.5, 786.5
Spreading code
(4,4), (8,4), (16,4), (32,4)
PSDU Data rate (bps)
500k,250k, 125.5k, 62.5k
Preamble spreading
(32,1) 7

8. 863 – 870 MHz PHY Chip rate = 200kcps Channel center frequency (MHz)
863.4, , 864.2, 865, 865.4, 866, 866.6, 867,2, 867.8, 868.3,
Spreading code
(4,4), (8,4), (16,4), (32,4)
PSDU data rate (bps)
200k, 100k, 50k, 25k
Preamble spreading
(32,1) 8

9. 902 – 928 MHz PHY Chip rate = 1Mcps Channelization Spreading code
400kHz channels, like Merged FSK Proposal, but not all used
Spreading code
(128,1), (32,1), (16,1), (32,4)
PSDU data rate
125k, 62.5k, 31.25k, 7.8k
Preamble spreading
(32,1) 9

10. 2400 – 2483.5 MHz PHY Chip rate = 1Mcps Channelization Spreading code
400kHz channels, like Merged FSK Proposal, but not all used
Spreading code
(128,1), (32,1), (16,1), (32,4)
Data rate (bps)
125k, 62.5k, 31.25k, 7.8k
Preamble spreading
(32,1) 10

11. (N,1) - FEC Concatenation11

12. (N,4) - FEC Concatenation12

13. PPDU Format PHR Field 2 octets Frame Length(11 bits)
4~2047
Bits: 64 8 11
Preamble
SFD
Data Rate Mode
Frame Length
Reserved
Parity Check
PSDU
Includes FCS
PHR Field
2 octets
Frame Length(11 bits)
Indicate the frame length from 0 – 2047 bytes
Compatible with PPDU Format of
Date Rate Field (2 bits)
Indicate the spreading sequence to binary data of PSDU, RX adjust receive PN sequence according to this field
Parity Check Field (1 bit)
Check the PHR field