January 2006

Ichihiko Toyoda, NTTSlide 1

doc.: IEEE 802.15-06/0007r0

Submission

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: [Single Carrier PHY for 60-GHz WPAN]Date Submitted: [January 13, 2006]Source: [Ichihiko Toyoda, Yasuo Suzuki, Kenjiro Nishikawa, and Tomohiro Seki] Company [NTT]Address [1-1 Hikari-no-oka, Yokosuka-shi, Kanagawa 239-0847, Japan]Voice:[+81-46-859-2366], FAX: [+81-46-855-1497], E-Mail:[toyoda.ichihiko@lab.ntt.co.jp]

Re: []

Abstract: [We discuss a modulation scheme for IEEE802.15.3c WPAN and evaluate a single carrier modulation using FSK/MSK and discriminator detection.]

Purpose: [To discuss suitable modulation scheme for IEEE802.15.3c PHY]

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.

January 2006

Ichihiko Toyoda, NTTSlide 2

doc.: IEEE 802.15-06/0007r0

Submission

Single Carrier PHY for 60-GHz WPAN

Ichihiko Toyoda,Yasuo Suzuki,

Kenjiro Nishikawa, andTomohiro Seki

(NTT)

January 2006

Ichihiko Toyoda, NTTSlide 3

doc.: IEEE 802.15-06/0007r0

Submission

Target Applications

• Simple high-speed connections between PCs and peripherals (GbE, IEEE1394, USB…)

• High-speed multimedia connections, heavy content downloads (video, music…)

• Office applications, ad-hoc meeting…

January 2006

Ichihiko Toyoda, NTTSlide 4

doc.: IEEE 802.15-06/0007r0

Submission

Application Requirements

• High speed connection (> 2 Gbit/s)• Low power consumption• Small size

January 2006

Ichihiko Toyoda, NTTSlide 5

doc.: IEEE 802.15-06/0007r0

Submission

Characteristics of 60-GHz Band

• Broad bandwidth available.• Practical small high-gain antennas.• Large propagation loss.• Underdeveloped mmW RF parts.

January 2006

Ichihiko Toyoda, NTTSlide 6

doc.: IEEE 802.15-06/0007r0

Submission

Comparison of Modulation Schemes

ASKFSK

(MSK)

PSK QAM

BPSK QPSK 8PSK 16QAM 64QAM

Frequency Efficiency

(bit/s/Hz)0.5 0.6 1.2 1.8 2.3 3.5

C/N

(dB)

(BER=10-5)

16.1(Envelope det.)

9.6(coherent det.)

10.3(differential det.,

discriminator det.)

9.6(coherent det.)

10.3(diff. det.)

12.6(coherent det.)

15.6(diff. det.)

17.9(coherent det.)

20.9(diff. det.)

22.1(coherent det.)

26.6(coherent det.)

TX amp.

Back-offSmall Non Small Large

January 2006

Ichihiko Toyoda, NTTSlide 7

doc.: IEEE 802.15-06/0007r0

Submission

Bandwidth or Power efficiency?

• Trade-off between frequency and power efficiency.• Power efficiency essential for WPAN applications.• Frequency efficiency not critical in 60-GHz band due

to broad bandwidth.

• Binary modulation suitable for WPAN applications.• FSK/MSK enables use of PAs in high-efficiency

regions.

January 2006

Ichihiko Toyoda, NTTSlide 8

doc.: IEEE 802.15-06/0007r0

Submission

SC-modulation or OFDM?

• Directional antennas essential in 60-GHz band due to large propagation loss. This results in less multi-path fading.

• Underdeveloped mmW RF parts, such as PA and LO. However, OFDM requires large back-off for PAs and high stability and low phase noise for LOs.

• OFDM requires complex signal processing which consumes more electricity.

January 2006

Ichihiko Toyoda, NTTSlide 9

doc.: IEEE 802.15-06/0007r0

Submission

Channel Plan

• Binary modulation requires wide bandwidth.• 4 independent channels cannot be allocated in 7

GHz.• Overlapped allocation is OK due to large propagation

loss and low power operation.• Another option is multi-value modulation like 4FSK

and QPSK.

59 66

January 2006

Ichihiko Toyoda, NTTSlide 10

doc.: IEEE 802.15-06/0007r0

Submission

Link BudgetTarget BER 1.00E- 05Oxygen attenuation 16 dB/ kmTemperature 300 K

Frequency 60 GHzData rate 2 GbpsAir rate 2.08 GbpsModulation MSKDemodulation Discriminator detectionEquivalent noise bandwidth 1.552 GHz

TX power 10 dBmTX antenna's gain 10 dBiRX antenna's gain 10 dBiNoise Figure 10 dB

January 2006

Ichihiko Toyoda, NTTSlide 11

doc.: IEEE 802.15-06/0007r0

Submission

Link Budget

0

5

10

15

20

25

30

35

40

45

0.0 2.0 4.0 6.0 8.0 10.0

Distance [m]

C/N

[d

B]

Received signal C/N (2 Gbps)

Theoretical C/N (BER=1E-5)

Required C/N

TX power: 10 dBmAntennas' gain: 10 dBi

Theoretical C/N

Required C/N

Required C/N = Theoretical C/N + Implementation loss (3 dB) + Inter Symbol Interference (3 dB)

January 2006

Ichihiko Toyoda, NTTSlide 12

doc.: IEEE 802.15-06/0007r0

Submission

Performance Evaluation

• Assume 2-ray model.• Delay time () much

greater than symbol period (T).

• Reflected level lower than -20 dB to direct signal. †

† T. Hirose, “Study of mm wave propagation modeling to realize WPANs,” IEEE802.15-03/0465-00-mmwi

t

>>T

Direct signalRicean (K=20 dB)

Delay signalRayleigh

20 dB

January 2006

Ichihiko Toyoda, NTTSlide 13

doc.: IEEE 802.15-06/0007r0

Submission

Performance Evaluation

• Directional antennas effectively reduce the effect of multi-path fading.

• Degradation by multi-path fading is less than 2 dB.

10-6

10-5

10-4

10-3

10-2

10-1

4 6 8 10 12 14 16

AWGNFading env.

BE

R

Eb/N

0 [dB]

GMSK (BbT=1.0)

Discriminator detectionRX filter BT=0.7fD=1000 Hz

January 2006

Ichihiko Toyoda, NTTSlide 14

doc.: IEEE 802.15-06/0007r0

Submission

Conclusion

• Power efficiency is the most important factor for mmW WPAN.

• Broad bandwidth is available in 60-GHz band.• Directional antennas are essential due to the

large propagation loss in 60-GHz band. These reduce multi-path fading effect.

• Single carrier modulation system is sufficient for WPAN system.