September 2004 Slide 1 doc.: IEEE 802.15- 04/514r0 Submiss ion Hiroyo Ogawa, NICT Project: IEEE P802.15 Working Group for Wireless Personal Area Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs) Networks (WPANs) Submission Title: [Simple Integrated Space Diversity System for mmW WPAN channel] Date Submitted: [14 September, 2004] Source: [Yozo Shoji, Kiyoshi Hamaguchi, and Hiroyo Ogawa] Company [National Institute of Information and Communications Technology, I.A.A.] Address [3-4, Hikarino-Oka, Yokosuka, Kanagawa, 234-0051, Japan] Voice:[+81.46.847.5070], FAX: [+81.46.847.5079], E-Mail: [ [email protected] ] Re: [] Abstract: [Description of diversity technology for mmW PAN channel model.] Purpose: [Contribution to mmW SG3c at September 2004 meeting.] 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
Transcript
September 2004
Slide 1
doc.: IEEE 802.15-04/514r0
Submission
Hiroyo Ogawa, NICT
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: [Simple Integrated Space Diversity System for mmW WPAN channel]Date Submitted: [14 September, 2004]Source: [Yozo Shoji, Kiyoshi Hamaguchi, and Hiroyo Ogawa] Company [National Institute of Information and Communications Technology, I.A.A.]Address [3-4, Hikarino-Oka, Yokosuka, Kanagawa, 234-0051, Japan]Voice:[+81.46.847.5070], FAX: [+81.46.847.5079], E-Mail:[ [email protected] ] Re: []
Abstract: [Description of diversity technology for mmW PAN channel model.]
Purpose: [Contribution to mmW SG3c at September 2004 meeting.]
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.
September 2004
Slide 2
doc.: IEEE 802.15-04/514r0
Submission
Hiroyo Ogawa, NICT
Simple Integrated Space Diversity System for mmW WPAN channel
September 2004
Slide 3
doc.: IEEE 802.15-04/514r0
Submission
Hiroyo Ogawa, NICT
Application of mmW PAN and Multipath Environment
mmW WPAN is useful for sharing the electrical handouts or presentation data among attendee in a small meeting.
Signal propagation on a desk causes multipath signal fading
Channel is modeled by 2-path model
D
Tx antenna d1
d2
Rx antenna
ht hr
September 2004
Slide 4
doc.: IEEE 802.15-04/514r0
Submission
Hiroyo Ogawa, NICT
Signal fading under 2-path channel modelPath loss seriously depends
on the height of transceiver’s antenna
When the height of transmission antenna is fixed, signal fading causes periodically
The higher the transmission antenna is, the shorter period signal fading causes
-85
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-75
-70
-65
-60
0 20 40 60 80 100Height of receiver antenna [mm]
Pa
th lo
ss P
r/P
t [d
B]
Tx antenna height = 85 mm
Tx antenna height = 200 mm
The use of Space Diversity Technique must be effective
September 2004
Slide 5
doc.: IEEE 802.15-04/514r0
Submission
Hiroyo Ogawa, NICT
Signal fading under 2-path channel model (cont’)
Path loss seriously depends on the transmission distance between transceivers
Signal fading causes but not at periodical distance.
The signal fading point depends on the height of antenna
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-50
0.5 1.0 1.5 2.0 2.5 3.0
Transmission distance [m]P
ath
loss
Pr/
Pt
[dB
]
Tx antenna height 85mmTx antenna height 200mm
The use of Space Diversity Technique must be effective
September 2004
Slide 6
doc.: IEEE 802.15-04/514r0
Submission
Hiroyo Ogawa, NICT
mmW Self-heterodyne Signal Transmission and Integrated Space Diversity Receiver
Receive signals with several receiver-modules integrated closely
Self-heterodyne technique reduces the received signal’s phase difference between Rx modules from （ 2πfRF )
into （ 2πfIF )
antennaSubharmonic Mixer
IF Inputport
BPF
Local Oscillator
Spectrum ofSSB type signal
LO RF
Spectrum of DSB type signal
LO RF
Antenna
LNA
BPF
Self-heterodyne MIX(Square-law detector)
Receiver module unitIF output port
21
Transmitter
Receiver
Transmit Local carrier along with RF modulated signal
Square-law detection of the both received signals
September 2004
Slide 7
doc.: IEEE 802.15-04/514r0
Submission
Hiroyo Ogawa, NICT
mmW Self-heterodyne Signal Transmission and Integrated Space Diversity Receiver (cont’)
antennaSubharmonic Mixer
IF Inputport
BPF
Local Oscillator
Spectrum ofSSB type signal
LO RF
Spectrum of DSB type signal
LO RF
Antenna
LNA
BPF
Self-heterodyne MIX(Square-law detector)
Receiver module unitIF output port
21
Transmitter
Receiver
Phase-noise and frequency offset free IF signal transmission without using expensive stable mmW local oscillator
Signals are combined approximately in the same phase for overall direction of signal arrival under the condition of ct << IF
Space diversity reception effect (including diversity gain effect) is expected
September 2004
Slide 8
doc.: IEEE 802.15-04/514r0
Submission
Hiroyo Ogawa, NICT
Developed Experimental mmW Transceiver with Integrated Spaced Diversity System
19 mm
September 2004
Slide 9
doc.: IEEE 802.15-04/514r0
Submission
Hiroyo Ogawa, NICT
Developed Experimental mmW Transceiver with Integrated Spaced Diversity System (Cont’)
RF Center Frequency 72.4 GHz
RF transmission scheme DSB Self-heterodyne
Communication scheme TDMA/TDD
Transmission power 10 mW
IF input frequency range 100 MHz ~ 800 MHz
Total receiver noise figure About 8 dB
Antenna gain 5 dBi
Type of Antenna Linear polarized wave-guide
Other notes Each receiver-module can be independently turned on/off
September 2004
Slide 10
doc.: IEEE 802.15-04/514r0
Submission
Hiroyo Ogawa, NICT
Improvement Effect on received CNR performance
Improves the detected IF power in proportion to the square of the number of receiver-modules
Also increases the noise power in proportion to the number of receiver-modules
Improves the received CNR in proportion to the number of receiver-module-array elements
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-30
-20
-10
0
10
0 1 2 3 4 5 6 7 8 9Number of receiver-modules
De
tec
ted
IF
po
we
r [d
Bm
]
-5
0
5
10
15
20
25
30
35
CN
R [
dB
/10
0M
Hz]
Signal (2m)Noise in 100MHz (2m)Signal (4m)Noise in 100MHz (4m)CNR (2m)CNR (4m)
Tx-Rx Distance = 2 m
September 2004
Slide 11
doc.: IEEE 802.15-04/514r0
Submission
Hiroyo Ogawa, NICT
Improvement Effect on received CNR performance (cont’)
Improves the received CNR in proportion to the number of receiver-module-array elements 2 elements >> 3 dB 8 elements >> 9 dB
Almost equal CNR improvement was obtained for the overall direction of signal arrival
-90 -60 -30 0 30 60 90
Direction of signal arrival [degree]
0
5
10
15
20
25
30
35
40
CN
R [
dB
/10
0M
Hz]
received by 8-eles.
received by 2-eles. (#1+#3)
received by 1-ele. (#1)
Tx-Rx Distance = 2 m
September 2004
Slide 12
doc.: IEEE 802.15-04/514r0
Submission
Hiroyo Ogawa, NICT
Slight change of antenna height with single antenna receiver seriously degrades the received signal level periodically
The use of several receiver-module can greatly compensate the signal fading height of receiver-module #1 [mm]
De
tec
ted
IF
po
we
r [d
Bm
]
#1#3 (height offset 38mm)Combination(#1+#3)
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-20
-10
0
10
20
40 60 80 100 120 140
Effect as a space-diversity receiver under multipath conditions
September 2004
Slide 13
doc.: IEEE 802.15-04/514r0
Submission
Hiroyo Ogawa, NICT
OFDM signal transmission experiment under multipath condition
IF center frequency 470 MHz
Access scheme TDMA/TDD (based on HyperLAN2)
Modulation BPSK, QPSK, 16QAM, 64QAM
FEC 1/2, 3/4, 9/16
Sampling rate Fs=1/T 20 MHz
Effective symbol time Tu 64T 3.2μS
Guard interval Tg 16T 0.8μS
Symbol length Ts 80T 4.0μS
Number of subcarrier N 52 = 48(data) + 4(pilot)
Subcarrier spacing 0.3125MHz (1/Tu)
Signal bandwidth 16.25MHz (N *)
September 2004
Slide 14
doc.: IEEE 802.15-04/514r0
Submission
Hiroyo Ogawa, NICT
OFDM signal transmission experiment under multipath condition (cont’)
Serious BER degradation occurred at some distances with single antenna receiver system
4 x 2 Receiver-module-arrayed system enabled error free transmission of OFDM signal over 1 ~ 4 m distance
0 1 2 3 4
Transmission Distance [m]
Bit
Err
or
Ra
te
1 element
8 elements
1.0E-07
1.0E-06
1.0E-05
1.0E-04
1.0E-03
1.0E-02
1.0E-01
1.0E+00
MOD=QPSKFEC=3/4
September 2004
Slide 15
doc.: IEEE 802.15-04/514r0
Submission
Hiroyo Ogawa, NICT
Conclusions The space diversity system is necessary
under mmW PAN channel, especially when the system is used on desk or table
Simple space diversity system based on self-heterodyne transmission technique, which can be integrated into small transceiver, was introduced
It was experimentally proved that diversity gain was obtained for all direction of signal arrival and that signal fading can be effectively avoided
