prof. jun-ichi takada propagation laboratory

MIMO-OFDM H/W evaluation

Prof. Jun-ichi Takada

Propagation Laboratory

Tokyo Institute of Technology

http://www.ap.ide.titech.ac.jp (Propagation lab), http://www.mcrg.ee.titech.ac.jp (MCRG)

Channel characterization and modeling for specific wireless communication systems

Advanced radio instrumentation and measurement techniques

Other topics

Wideband directional propagation channel analysis inside an arched tunnel Influence of Fresnel zone in Ray-tracing simulationComparison of directional channel measurement and Ray-tracing simulation in university campusIdentification of relevant clusters at an Urban MIMO macro cellPropagation characteristics in outdoor environment for MIMO systemScatter identification and stochastic modeling of street micro cellUltra wideband propagation channel measurement

Propagation measurement system for ETC gateRadio source localization using array antennas based on fingerprint techniques in outdoor environment

Performance Evaluation of Analog Adaptive Array Antennas for mobile applications

Cognitive radio coexisting with TV broadcasting services

Recent Research Projects of Propagation LaboratoryRecent Research Projects of Propagation Laboratory

MCRG @ Tokyo Tech.MCRG @ Tokyo Tech.

Weekly seminar is regularly held with membersOpen house is held every year to introduce our activities Outcomes are open to outside through annual report

IEEE802.16e MIMO prototype

Anechoic chamber

MIMO cellular/mesh network, SDR, Tree-Structure user scheduling algorithm, High speed Tx-reference UWBSystem Lab.

MIMO-OFDM Implementation, Reliable Signal Detection, CCI Canceller for MIMO-OFDM, Efficient Packet Protocol

Signal Processing Lab.

Slotted Waveguide Arrays, FWA, Millimeter wave, High Frequency Analysis for DiffractionAntenna Lab.

Channel characterization and modeling, Advanced radio instrumentation and measurement, Other related topics Propagation Lab.

Prof. H. Suzuki, Assoc. Prof. K. Fukawa and Assist. Prof. S. Suyama

Prof. K. Araki and Assist. Prof. K. Sakaguchi

Prof. M. Ando, Assoc. Prof. J. Hirokawa, Assist. Prof. K. Sakurai and Assist. Prof. H. Hirano

Prof. J. Takada and Assist. Prof. M. Kim

MCRG members





y

xnfnf−⎥⎦⎤

⎢⎣⎡ −++−−

=xnxnx Cfxfx

s eP22 )()( αα

⎥⎦⎤

⎢⎣⎡ −++++−−

=yynxynx Cyfxyfx

b eP2222 )()( αααα

BS MS

⎥⎦⎤

⎢⎣⎡ −++++−−

=yynxynx Cyfxyfx

b eP2222 )()( ααααbuilding zone

building zone

street zone

LoS zone

Physical PhenomenaIn a street microcell, multiscattering is dominant

compared to free space path loss.Locus of multiscatterings are parallel lines

symmetric to the middle line of the street.

Proposed ModelThe scattering power diminishes fast in the building zone, along y axis. The attenuation

across the x axis in the street zone has a slower rate.The scattering distribution for 3 zones: street zone, building zones and LoS component

are defined.

Single-bounce Scattering Power Distributions

Street Width =10m

Traditional

Likely

Ellipses

Locus ofScatterers

The scattering distribution for the LoS component is a circular disc in which the scattering power is decreasing exponentially from the center (Tx, here MS) along the radial lines. This is to consider the resolution in delay and AoAdomains.

0 90 180 270 360-60

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eive

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wer

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]

Azimuth-of-arrival [°]

Measurement 1Measurement 2GBSBEMProposed

0 5 10 15 20 25 30 35-50

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Normalized Delay [(τ-τ0)/Tw]

Measurement 1Measurement 2GEMProposed

Power Delay Profile

Street width=26 m

Azimuth Power Spread

Street width=26 m

(by Mir Ghoraishi)2-dimensional stochastic channel model for line-of-sight street microcell

(by Navarat Lertsirisopon )Comparison of directional channel measurement and Ray-tracing simulation

Location Street Width [m]1 262 183 10

xα3100.1 −×

yα4100.1 −×

3100.2 −×3100.3 −×

4100.2 −×4101.2 −×

Coefficients of the Model Obtained by Approximation to the Measurement Data

(BS-MS Separation of 60 m and BS and MS Height of 3 m)

The microcell measurement was carried out in O-okayamacampus of Tokyo Institute of Technology. The MedavRUSK Fujitsu channel sounder was employed to accomplish the measurements.

To simulate the measurement by using ray-tracing output,the array frequency response is constructed as

By incooperating 3D site-specific scenario information, the ray-tracing simulator called “Raplab” is used to predict detailed path parameters.

To trace rays from a source to the observation point, the image method is utilized to find ray paths and angle. The formulation of reflected and diffracted rays are carried out based on geometrical optics (GO), and the uniform theory of diffraction (UTD)

BS MS

Measurement Scenario and Equipment Path Determination using Ray-Tracing

Channel Data Processing Reconstruction

Beamforming is applied in every 6o for the azimuth range (from 0o

to 360o), and for the co-elevation range (from 30o to 150o) according to antenna limitations. The resultant spectrum

Beamforming and the matched filtering are conducted by using weight vector

Azi

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oele

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ectr

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uth-

Del

aySp

ectr

um





The need to model the collection of multipaths that lie in the “same” angle-delay domain, or clusters, is also one of the things needed to approach the full performance advantage of Multiple-Input Multiple-Output (MIMO) systems for future cellular communications.Properly characterizing clusters (collection of multipaths that lie in the “same” angle-delay domain) is also started by correctly

identifying them.A clustering method is being developed for identifying clusters in an urban macrocell, where wideband MIMO antennas were used.

(by Materum Lawrence)Identification of Relevant Clusters in an Urban MIMO Macrocell

(by Tomoshge Kan)Propagation characteristics in outdoor environment for MIMO system

Carrier frequency 4.5 GHzBandwidth 120 MhzBS Antenna Uniform Rectangular Array

V & H polarization4-x-2 patch antenna elements

MS Antenna Stacked Uniform Circular ArrayV & H polarization24-x-2 patch antenna elements

Tx Signal Wideband Multicarrier Spread SpectrumTx Power 40 dBmMaximum path delay 3.2 µs

We would like to thank National Institute of Information and Communications Technology of Japan (NICT) for supporting this research.

The propagation environment is important for effect of MIMO. Many studies pertaining to MIMO systems in indoor environments were conducted. A studies pertaining to MIMO system in outdoor environments such as cellular system is required. We plan measurement in outdoor environment for MIMO system.

Tx Rx

Rx

Txreflection

diffractionh11

h12h21

h22

1

2 2

1

sync sync

TRIG

10MHz 10MHz

(master) (master)

(slave) (slave)

TX RXTXh

11h

21

h12

h22

<A MIMO measurement block diagram >

< MIMO System > < Outdoor Environment >

The propagation environment isimportant for effect of MIMO.

< Channel Modeling >There are a lot of scatterers (buildings in outdoor environment). Rx receive a lot of waves by reflection, diffraction and etc...Propagation environment measurement experiment.

Propagation characteristics that a power profile, a path loss, ashadowing, a Doppler shift are measured.

The measurement experiment in an outdoor environment of urban area is conducted by setting up the antenna to outside or inside the vehicle.A measurement equipment for 2×2 MIMO system is like a TDM.A antenna setting is a space diversity.A center frequency is 3.35GHz.

< Measurement Scenario >

UWB signals have relative bandwidth larger than 20% or absolute bandwidth of more than 500MHz. This property allows extremely accurate location estimates using time-based techniques via UWB radios.The time of arrival (TOA) data fusion method is based on

combining estimates of the TOA of the MS signal when arriving at three different BSs. An important source of error is in the case where there is no

line of sight from the mobile station to the BSs.A geometrically constrained data fusion scheme could be used

to reduce the effect of such NLOS conditions. the constraint can be the distances between the BSs. xm

ym

xm

y m TOA

1xm

ym AoA

; i-th RX location coordinates ; TX location coordinates

x i , y i

xm , ym

(by Dashti Marzieh)UWB Localization

Hybrid localization method can be used to have a more accurate location estimate. linear combination of more than oneschemes (for example; ToA and AoA) can be done.

Radio source localization using array antennas based on fingerprint techniques inoutdoor environment



Advanced radio instrumentation and measurement techniquesAdvanced radio instrumentation and measurement techniques(by Assist. Prof. M. Kim)Propagation measurement system for ETC gate

(by Panarat Cherntanomwong)

Other related topicsOther related topics(by Po Kim Tho)

Cognitive radio coexisting with TV broadcasting services

Receiving point(Array antenna)

Reference Station 3

Reference station 2

Reference Station 1

0 degreesx

y(0,0,0)

Receiving point(Array antenna)

Reference Station 3

Reference station 2

Reference Station 1

0 degreesx

y(0,0,0)

P50 P60 P70 P80 P90

P50

P60

P70

P80

P90

Database location index

Estim

ated

loca

tion

inde

x

Signal subspace fingerprintProposed fingerprint: Measured usProposed fingerprint: Interpolated us

0 P100 P200 P300 P400 P500 P600 P7000

P100

P200

P300

P400

P500

P600

P700

Database location index

Estim

ated

loca

tion

inde

x

Signal subspace fingerprintProposed fingerprint: Measured usProposed fingerprint: Interpolated us

Estimated locations of transmitters at 50-m distance location

Estimated locations of transmitters at 10-m distance location

• The performance is verified by the outdoor experiment estimating the transmitter (car) position in the racing car circuit.

•For 10-m distance location, the accurate estimated location can be observed,while it is not so for 50-m distance location, in case of P150 and P250.

•The proposed method works well for interpolating in the short distance.

• Instead of using the measured signal subspace to construct the database, the interpolated signal subspaces obtained by priori known signal subspaces are used. (The subspace matching is an algorithm to estimate the transmitter location by matching two signal subspaces.)

• Most of today's radio systems are not aware of their radio spectrum environment and operate in a specific frequency band using a specific spectrum access system.

• Many channels in the TV band are significantly underutilized.

Cognitive Radio

IEEE 802.22Wireless Regional

Area Network

Solution

- Investigation of the applicability of IEEE 802.22 WRAN to Japan.- Study the impact of IEEE 802.22 WRAN system on TV systems- Study of spectrum sensing for cognitive radio.

Research Objectives

Spectrum Sensing• Energy detector• Replica-Correlation Detector• Cyclostationarity Detector

In order to allow CR for IEEE 802.22 system operate in TV band, probability of detection is greater than 0.9 and probability of false alarm is less than 0.1 should be met.

Energy Detector Model

RF block8ch receiver with coherent LO

ADC block8ch synchronous A/D converter

DSP blockHybrid FPGA and DSP architecture

CPU blockWindows PC

theta [deg]

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• Electronic Toll Collection (ETC), an application of Dedicated Short Range Wireless Communication (DSRC), had suffer from wrong operations due to multi-path problems. To specify the multi-path characteristics useful propagation measurement system was devised.

< Multi-path problem of ETC >

< Processing Flow > < System specifications >< Simulated spectrum by

beamforming in 4-path mode > ⎪⎭

⎪⎬⎫

⎪⎩

⎪⎨⎧

++−= −

20

20

20

010

)(cos

zyxx

zθ

• The vehicle for measurement performs burst-wise data capture with constant time interval passing through the ETC gates at around 20km/h and.• The triggers at start and end points of burst data capture are issued by laser sensors lorded in the vehicle.• After data capturing, the power spectra are generated by beamforming with burst data along X-axis.• From the resulting spectrum we can determine the DOA at the position x as

• This system can estimate not only spatial power distribution but the scattering process and the intensity of incident signals with real ETC signals.• The measurement can be conducted driving the vehicle that load this system without closing the ETC lane for the measurement.

Features of proposed system

E-1070(KODEN)

Measurement principle< Communication area of ETC >

prof. jun-ichi takada propagation laboratory

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