Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs)
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Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs) Submission Title: [MPSK Modulation for PHY Layer Proposal for Chinese Band] Date Submitted: [30−Aug−2007]

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Project ieee p802 15 working group for wireless personal area networks wpans

Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs)

Submission Title: [MPSK Modulation for PHY Layer Proposal for Chinese Band]

Date Submitted: [30−Aug−2007]

Source: [Liang Li, ChenYang Yang T.T. Liu, Pei Liu, Dixon Paul] Company: [Vinno Technologies Inc, BUAA, Hisilicon Inc. ]

Address: [Suite 402, Building D, No.2 Shangdi Xinxi Lu, Beijing 100085, China]

Voice:[8610-82782373], FAX: [8610-82893004]

E−Mail: [[email protected], [email protected]]

Re: [802.15.4c]

Abstract: [ ]

Purpose: [To encourage discussion in 802.15.4c]

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.

Liang Li (Vinno), C.Y. Yang (BUAA)


Proposal

Proposal

  • A new PHY Proposal for low-rate WPAN that employs the MSPK modulation scheme with new DSSS sequences:

  • The MPSK tech is adopted as the basic modulation of communication in LR-WPAN at 780mhz New DSSS sequences: 16 sequences for 4-bit mapping.

  • Data rate =250Kbps.

  • Channel separation = 2MHz.

  • The 1st null-null bandwidth = 750KHz.

Liang Li (Vinno), C.Y. Yang (BUAA)


The important operation coefficients

The Important Operation Coefficients

Fc=780, 782, 784, 786 MHz

The Transmit Path (I or Q Paths)

Liang Li (Vinno), C.Y. Yang (BUAA)


Dsss mapping symbol to chips

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)


Pre processing

Pre-Processing

  • Remove DC component

    The DC components 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)


Proposal for preamble

Proposal for preamble

  • SFD Processing

  • ---- The SFD sequence is the conjugate of the Preamble sequence

The Phase sequence of SFD is:

The Phase sequence of Preamble is:

Liang Li (Vinno), C.Y. Yang (BUAA)


Pulse shaping filter

0

1

0.8

-10

0.6

-20

Pluse Shape

0.4

PSD (dB)

-30

0.2

-40

0

-50

-0.2

-2

-1.5

-1

-0.5

0

0.5

1

1.5

2

-60

-2

-1.5

-1

-0.5

0

0.5

1

1.5

2

t [Tc]

f [MHz]

Pulse Shaping Filter

The Pulse Shaping Filter on I and Q path is Raise-Cosine ( t=0.5 ):

Liang Li (Vinno), C.Y. Yang (BUAA)


Modulation mpsk

Modulation MPSK

Liang Li (Vinno), C.Y. Yang (BUAA)


Proposal for preamble1

Proposal for preamble

The preamble field proposed here consists of at least 4octets, which is same as ones of OQPSK at 915MHz of IEEE 802.15.4-2006

Liang Li (Vinno), C.Y. Yang (BUAA)


Promoted communication tech in lr wpan 4

1

0.5

Real

0

20

-0.5

10

-1

0

2

4

6

8

10

12

14

16

0

t / Tc

-10

1

PSD

0.5

-20

Imag

0

-30

-0.5

-1

-40

0

2

4

6

8

10

12

14

16

t / Tc

-50

-60

-2

-1.5

-1

-0.5

0

0.5

1

1.5

2

f/MHz

Promoted Communication Tech in LR-WPAN(4)

  • 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 )

Liang Li (Vinno), C.Y. Yang (BUAA)


Psd in the band

PSD in the Band

  • PSD requirements in Band

  • Minimum Receiver Jamming Resistance Requirement

Liang Li (Vinno), C.Y. Yang (BUAA)


Evm crest fractor and constellation chart

1.5

1

0.5

Imag Rart

0

-0.5

-1

-1.5

-2

-1.5

-1

-0.5

0

0.5

1

1.5

Real Part

EVM, Crest fractor and Constellation Chart

MPSK Constellation Chart

(Nyquist sampling points)

Constellation chart

(RC-pulse shaping):

Liang Li (Vinno), C.Y. Yang (BUAA)


Performance synchronization performance

0

10

-1

10

-2

10

-3

Sync Error Rate

10

-4

10

-5

10

-6

10

4

4.5

5

5.5

6

6.5

7

7.5

8

8.5

9

E

/n

b

0

Performance: Synchronization Performance

Simulation Condition: In AWGN channel, ideal synchronization,

20 data octets in each packet, sync algorithm is sliding correlation.

Liang Li (Vinno), C.Y. Yang (BUAA)


Performance demodulation performance

0

10

-1

10

-2

PER

10

-3

10

-4

10

4

4.5

5

5.5

6

6.5

7

7.5

8

8.5

9

E

/n

b

0

Performance: Demodulation Performance

Simulation Condition: In AWGN channel, ideal synchronization,

Correlation demodulation, 20 data octets in each packet

Liang Li (Vinno), C.Y. Yang (BUAA)


Performance performance under sync and freq offset

0

10

AWGN

+/-20ppm

+/-40ppm

+/-80ppm

-1

10

+/-120ppm

-2

PER

10

-3

10

-4

10

4

4.5

5

5.5

6

6.5

7

7.5

8

8.5

9

E

/n

b

0

Performance: Performance under sync and freq-offset

Simulation Condition: In AWGN channel, with sync and freq-offset Estimation,

20 data octets in each packet

Liang Li (Vinno), C.Y. Yang (BUAA)


Performance in multipath channel 1

Performance in Multipath Channel (1)

  • Tapped-Delay-Line Channel Model

    • IEEE P802.15 Working Group for WPANs, Multipath Simulation Models for Sub-GHz PHY Evaluation, 15-04-0585-00-004b, Oct. 2004.

    • 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.

  • Short Delay Environments

    • Without rake receiver

  • Long Delay Environments

    • With 3-tap rake receiver

Liang Li (Vinno), C.Y. Yang (BUAA)


Performance in multipath channel 2

Performance in Multipath Channel (2)

  • Test Conditions

    • RMS delay spread 0~250ns

    • Tx nonlinear amplifier, Rapp’s model, p=3, backoff=1.5dB

    • Tx and Rx frequency offset ±80ppm, phase noise -110dBc/Hz @±1MHz

    • Tx and Rx IQ imbalance 2dB, 10o

    • 3bit AD sampling, 8bit baseband processing

    • Rx will implement time and frequency synchronization and data detection

    • 5000 packets are tested for each SNR, each packet comprises 20 octets

    • The packet error rate is counted for 90% coverage

Liang Li (Vinno), C.Y. Yang (BUAA)


Per in short delay environments without rake receiver

0.5

0 ns

0.45

50 ns

100 ns

0.4

250 ns

0.35

0.3

0.25

PER

0.2

0.15

0.1

0.05

0

10

11

12

13

14

15

16

17

18

19

20

E

/N

(dB)

b

0

PER in Short Delay Environments without Rake Receiver

Liang Li (Vinno), C.Y. Yang (BUAA)


Per in long delay environments with 3 tap rake receiver

0.5

0 ns

0.45

100 ns

200 ns

0.4

300 ns

400 ns

0.35

500 ns

600 ns

0.3

0.25

PER

0.2

0.15

0.1

0.05

0

10

11

12

13

14

15

16

17

18

19

20

E

/N

(dB)

b

0

PER in Long Delay Environments with 3-tap Rake Receiver

Liang Li (Vinno), C.Y. Yang (BUAA)


Project ieee p802 15 working group for wireless personal area networks wpans

PICS

Table C.4 Radio Frequencies

Liang Li (Vinno), C.Y. Yang (BUAA)


Project ieee p802 15 working group for wireless personal area networks wpans

Summary

  • Regulatory rules for China may require reduced side lobes: -36 dBm @ non specified distance from carrier

  • Robust non-coherent detection of MPSK-RC can be achieved with well-known differential MSK-type detectors with no loss in performance, i.e. performance is same as the OQPSK mode @ 900 MHz

  • RC shaping is recommended w.r.t. EVM < 35%

  • The MPSK modulation are recommended as one of proposals to implement the PHY layer operation in LR-WPAN.

Liang Li (Vinno), C.Y. Yang (BUAA)


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