1. Date Submitted: [10−Nov−2007]
Project: IEEE P Working Group for Wireless Personal Area Networks (WPANs)
Submission Title: [MPSK Modulation for PHY Layer Proposal for Chinese Band]
Date Submitted: [10−Nov−2007]
Source: [Liang Li, T.T. Liu, ChenYang Yang, Pei Liu, Bill Zhang] Company: [Vinno Technologies Inc, BUAA, Hisilicon Inc. ASTRI Inc.]
Address: [Suite 402, Building D, No.2 Shangdi Xinxi Lu, Beijing , China]
Voice:[ ], FAX: [ ]
E−Mail:
Re: [ c]
Abstract: [ ]
Purpose: [To encourage discussion in c]
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
Liang Li (Vinno), C.Y. Yang (BUAA)

2. Nov 2007
Proposal
A new PHY Proposal for low-rate WPAN that employs the MPSK modulation scheme with new DSSS sequences:
MPSK is adopted as the basic modulation of communication for the LR-WPAN in the 780Mhz band.
New DSSS sequences: 16 sequences for 4-bit mapping.
Data rate = 250Kbps.
Channel separation = 2MHz. The 1st null-null bandwidth = 750KHz.
Pt < 10mw.
Liang Li (Vinno), C.Y. Yang (BUAA)

3. The Important Operating Coefficients
Nov 2007
The Important Operating Coefficients
Band (MHz)
Communication Coefficients
Chip Rate
(M chip/s)
Modulation
Bit Rate (Kbit/s)
Symbol Rate (K symbol/s) 1
MPSK
250
62.5
Fc=780, 782, 784, 786 MHz
The Transmit Path (I or Q Paths)
Liang Li (Vinno), C.Y. Yang (BUAA)

4. DSSS Mapping (Symbol to Chips)
Nov 2007
DSSS Mapping (Symbol to Chips)
The Direct Sequence Spread Spectrum (DSSS) tech is applied
16 orthogonal spreading sequences are designed to map 4 information bits. The base sequence is a 16-length chirp sequence and the other 15 sequences are its cyclic shifts.
Liang Li (Vinno), C.Y. Yang (BUAA)

5. The DC component of one base sequence is
Nov 2007
Pre-Processing
Remove DC component
The DC component of one base sequence is
Subtract ADC from each chip directly in the processing, all DC components of PPDU can be mitigated.
Liang Li (Vinno), C.Y. Yang (BUAA)

6. Nov 2007
PPDY Packet
The Preamble sequence is defined as: 8 symbols [0X00 0X00 0X00 0X00](128s),
The SFD sequence is defined as: 2 symbols [0XA7](32s).
Liang Li (Vinno), C.Y. Yang (BUAA)

7. Spread Sequences Advantage(1)
Nov 2007
Spread Sequences Advantage(1)
Distinguish auto-correlation property (Left: ones of 16-lenght Chirp sequence, Right: ones of 16-length Sequences in (915MHz) QPSK)
Obtain better synchronization performance.
Reduce inter-chip interference in multipath environments. -8 -6 -4 -2 2 4 6 8
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9 1
t/Tc
Auto-Correlation Property -8 -6 -4 -2 2 4 6 8
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9 1
t/Tc
Auto-Correlation Property
Liang Li (Vinno), C.Y. Yang (BUAA)

8. Spread Sequences Advantage(2)
Nov 2007
Spread Sequences Advantage(2)
The correlation characteristic with frequency offset
s(t) —preamble
— time delay
f—frequency offset
Liang Li (Vinno), C.Y. Yang (BUAA)

9. Spread Sequences Advantage(2)
Nov 2007
Spread Sequences Advantage(2)
Distinguish correlation characteristic
The Frequency offset consists of integral frequency offset and fractional frequency offset;
The correlation characteristic is repeated on integral frequency offsets;
The impact of integral frequency offset may be treated as that of the time delay, and has no effect on the timing;
Only the fractional frequency offset affects the correlation characteristic.
where kf1 is the integer frequency offset
Liang Li (Vinno), C.Y. Yang (BUAA)

10. Spread Sequences Property of OQPSK
Nov 2007
Spread Sequences Property of OQPSK
The correlation characteristic of OQPSK with frequency offset
s(t) —preamble
—time delay
f—frequency offset
Liang Li (Vinno), C.Y. Yang (BUAA)

11. Nov 2007
Pulse Shaping Filter
The Pulse Shaping Filter on I and Q paths is Raised-Cosine (α=0.5 ): -2
-1.5 -1
-0.5
0.5 1
1.5 2
-0.2
0.2
0.4
0.6
0.8
t [Tc]
Pluse Shape -2
-1.5 -1
-0.5
0.5 1
1.5 2
-60
-50
-40
-30
-20
-10
f [MHz]
PSD (dB)
Liang Li (Vinno), C.Y. Yang (BUAA)

12. Waveforms and PSD of Transmit Signals
Nov 2007
Waveforms and PSD of Transmit Signals
The Transmit Waveforms (I and Q) and Spectrum are:
( Condition: RC shaping filter, Random chip sequence, 100 kHz resolution band width, 0 dBm TX-power ) 2 4 6 8 10 12 14 16 -1
-0.5
0.5 1
Real
t / Tc
Imag
0.2
0.4
0.6
0.8 1
1.2
1.4
1.6
1.8 2
-50
-40
-30
-20
-10
f [MHz]
PSD
BW=100KHz
(f) [dBm]
MPSK RC-0.5
PSD MASK -36dBm
Liang Li (Vinno), C.Y. Yang (BUAA)

13. Minimum Receiver Jamming Resistance Requirement
Nov 2007
PSD in the Band
PSD Requirements in Band
Minimum Receiver Jamming Resistance Requirement
Liang Li (Vinno), C.Y. Yang (BUAA)

14. EVM, and Crest factor The Envelop is non-constant.
Nov 2007
EVM, and Crest factor
The Envelop is non-constant.
The EVM and Crest Factor are:
(RC-0.5-pulse shaping ):
EVM [%]
Crest factor [dB]
MPSK-RC-0.5
0 (Nyquist)
2.87
Liang Li (Vinno), C.Y. Yang (BUAA)

15. Performance: Synchronization Performance
Nov 2007
Performance: Synchronization Performance
Simulation Condition: In AWGN channel, 20 data octets in each packet,
sliding-correlation algorithm is used for sync . 4
4.5 5
5.5 6
6.5 7
7.5 8
8.5 9 10 -6 -5 -4 -3 -2 -1 E b /n
Sync Error Rate
Liang Li (Vinno), C.Y. Yang (BUAA)

16. Performance: Demodulation Performance
Nov 2007
Performance: Demodulation Performance
Simulation Condition: In AWGN channel, ideal synchronization,
Correlation demodulation, 20-octet data in each packet 4 5 6 7 8 9 10 -4 -3 -2 -1 E b /N
PER
MPSK (Coherent Detect)
MPSK (Non-Coherent Detect)
Liang Li (Vinno), C.Y. Yang (BUAA)

17. Performance Comparison
Nov 2007
Performance Comparison
Simulation Condition: In AWGN channel, Coherent Correlation demodulation,
20-octet data in each packet 4 5 6 7 8 9 10 -4 -3 -2 -1 E b /N
PER
Coherent Detect
MPSK (ideal)
MPSK (Sync)
O-QPSK (ideal)
O-QPSK (Sync)
Liang Li (Vinno), C.Y. Yang (BUAA)

18. Performance Comparison
Nov 2007
Performance Comparison
Simulation Condition: In AWGN channel, Non-coherent Correlation demodulation,
20-octe data in each packet 4 5 6 7 8 9 10 -4 -3 -2 -1 E b /N
PER
Non-Coherent Detect
MPSK (ideal)
MPSK (Sync)
O-QPSK (ideal)
O-QPSK (Sync)
Liang Li (Vinno), C.Y. Yang (BUAA)

19. Performance: Performance under Sync and Freq-offset
Nov 2007
Performance: Performance under Sync and Freq-offset
Simulation Condition: In AWGN channel, sliding correlation sync method and tranditional freq-offset estimation and correction, 20-octet data in each packet 4 5 6 7 8 9 10 -4 -3 -2 -1 E b /N
PER
MPSK 0ppm
MPSK 20ppm
MPSK 40ppm
MPSK 60ppm
Liang Li (Vinno), C.Y. Yang (BUAA)

20. Performance in Multipath Channel
Nov 2007
Performance in Multipath Channel
Tapped-Delay-Line Channel Model
IEEE P Working Group for WPANs, Multipath Simulation Models for Sub-GHz PHY Evaluation, b, Oct
Power delay profile is exponentially declined.
Each path is independently Rayleigh fading.
The average power of the channel response over many packets is 1, but in each packet the power is varied.
Flat Fading Channel
Without rake receiver
Frequency Selective Channel
Liang Li (Vinno), C.Y. Yang (BUAA)

21. Performance: in Flat Fading Channel
Nov 2007
Performance: in Flat Fading Channel
Simulation Condition: In the Rayleigh fading channel, Delay Spread RMS = 0ns,
with synchronization, 0ppm frequency offset, Non-coherent demodulation,
20-octet data in each packet 5 10 15 20 25 30 35 40 -4 -3 -2 -1 E b /N
PER
Liang Li (Vinno), C.Y. Yang (BUAA)

22. Performance: Under Multipath Channel
Nov 2007
Performance: Under Multipath Channel
Simulation Condition: In the Rayleigh multipath channel, Delay Spread RMS = 250ns,
with synchronization, 0ppm frequency offset, Non-coherent demodulation,
20-octet data in each packet 5 10 15 20 25 30 35 40 -4 -3 -2 -1 E b /N
PER
Liang Li (Vinno), C.Y. Yang (BUAA)

23. Performance Comparison
Nov 2007
Performance Comparison
Simulation Condition: In the Rayleigh multipath channel, Delay Spread RMS = 250ns,
with synchronization, 0ppm frequency offset, Non-coherent demodulation,
20-octet data in each packet 5 10 15 20 25 30 35 40 -4 -3 -2 -1 E b /N
PER
MPSK t
rms
= 0ns
= 250ns
O-QPSK
Liang Li (Vinno), C.Y. Yang (BUAA)

24. Performance: In Multipath Channel
Nov 2007
Performance: In Multipath Channel
Simulation Condition: In the Rayleigh multipath channel, Delay Spread RMS = 250ns,
with synchronization, Non-coherent demodulation,
20 data octets in each packet 5 10 15 20 25 30 35 40 -4 -3 -2 -1 E b /N
PER
MPSK (Rake)
O-QPSK (Rake)
MPSK (NoRake)
O-QPSK (NoRake)
Liang Li (Vinno), C.Y. Yang (BUAA)

25. PICS Item number Item description Reference Status Support N/A Yes No
Nov 2007
PICS
Table C.4 Radio Frequencies
Item number
Item description
Reference
Status
Support
N/A
Yes No
RF1
868 / 915 MHz PHY
O.3
RF1.1
Sub-1-Ghz 600kHz (20 kbit/s) M
RF1.2
Sub-1-Ghz 2 MHz (40 kbit/s)
RF1.3
Sub-1-Ghz 2 Mhz (250 kbit/s) O
RF1.4
Sub-1-Ghz 600 kHz (100 kbit/s)
RF1.5
Sub-1-Ghz 780 kHz (250 kbit/s)
RF2
2450 Mhz PHY 5 Mhz (250 kbit/s)
Liang Li (Vinno), C.Y. Yang (BUAA)

26. Nov 2007
Summary
Regulatory rules for China may require reduced side lobes: -36 dBm outside of the MHz Band.
The non-coherent demodulation of MPSK-RC can achieve same performance with differential MSK-type detectors, i.e. performance is same as the OQPSK 900 MHz.
RC shaping is recommended w.r.t. EVM < 35%
MPSK modulation is recommended as one of proposals to implement the PHY layer operation in LR-WPAN.
Liang Li (Vinno), C.Y. Yang (BUAA)

27. Nov 2007
Backup Slides
Liang Li (Vinno), C.Y. Yang (BUAA)

28. Promoted Communication Tech in LR-WPAN
Nov 2007
Promoted Communication Tech in LR-WPAN
The Transmit Waveforms (I and Q) and Spectrum are:
( Condition: RC shaping filter, Random chip sequence, 100 kHz resolution band width, 0 dBm TX-power ) 2 4 6 8 10 12 14 16 -1
-0.5
0.5 1
Real
t / Tc a
= 0.5
= 0.8
Imag
0.2
0.4
0.6
0.8 1
1.2
1.4
1.6
1.8 2
-50
-40
-30
-20
-10
f [MHz]
PSD
BW=100KHz
(f) [dBm]
MPSK RC-0.5
MPSK RC-0.8
PSD MASK -36dBm
MPSK-RC-0.5: Crest factor (2.87dB), MPSK-RC-0.8: Crest factor (3.05dB)
Liang Li (Vinno), C.Y. Yang (BUAA)

29. Performance Comparison
Nov 2007
Performance Comparison
Simulation Condition: In AWGN channel, with sync and freq-offset estimation and correction,20 data octets in each packet 4 5 6 7 8 9 10 -4 -3 -2 -1 E b /N
PER
MPSK 0ppm
MPSK 20ppm
MPSK 40ppm
MPSK 60ppm
O-QPSK 0ppm
O-QPSK 20ppm
O-QPSK 40ppm
O-QPSK 60ppm
Traditional freq-offset estimation method:
Liang Li (Vinno), C.Y. Yang (BUAA)

30. Performance under Non-linear Power Amplifier
Nov 2007
Performance under Non-linear Power Amplifier
Correlation property with non-linear power amplifier
The model of nonlinear PA was proposed by 15.4b group in 2004 -8 -6 -4 -2 2 4 6 8
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9 1
t/Tc
Correlation Property
In the linear area
In the saturated area
+1.0
-1.0
Vout
Vin
Linear area of PA
Saturated area of PA
Liang Li (Vinno), C.Y. Yang (BUAA)

31. Promoted Communication Tech in LR-WPAN
Nov 2007
Promoted Communication Tech in LR-WPAN
The PSD before and after PA:
Before PA
After PA
Liang Li (Vinno), C.Y. Yang (BUAA)