UWB Channel Model for Indoor Residential Environment

1
Project IEEE P802.15 Working Group for Wireless
Personal Area Networks (WPANs) Submission Title
UWB Channel Model for Indoor Residential
Environment Date Submitted 16 September,
2004 Source Chia-Chin Chong, Youngeil Kim,
SeongSoo Lee Company Samsung Advanced
Institute of Technology (SAIT) Address RF
Technology Group, Comm. Networking Lab., P. O.
Box 111, Suwon 440-600, Korea. Voice82-31-280-
6865, FAX [phone], E-Mail
chiachin.chong_at_samsung.com Re Response to
Call for Contributions on IEEE 802.15.4a Channel
Models Abstract This contribution describes
the UWB channel measurement results in indoor
residential environment based in several types of
high-rise apartments. It consists of detailed
characterization of both the large-scale and
small-scale parameters of the channel such as
frequency-domain parameters, temporal-domain
parameters, small-scale amplitude statistics and
S-V clustering multipath channel parameters of
the UWB channel with bandwidth from 3 to 10
GHz. Purpose Contribution towards the IEEE
802.15.4a Channel Modeling Subgroup. 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.
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UWB Channel Model for Indoor Residential
Environment

• Chia-Chin Chong, Youngeil Kim, SeongSoo Lee
• Samsung Advanced Institute of Technology (SAIT),
  Korea

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Outline

• Measurement Setup Environment
• Data Analysis Post-Processing
• Measurement Results
• Large-Scale Parameters
• Small-Scale Parameters
• Conclusion

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Measurement Setup (1)

• Frequency domain technique using VNA
• Center frequency, fc 6.5GHz
• Bandwidth, B 7GHz (i.e. 3-10GHz)
• Delay resolution, ?? 142.9ps (i.e. ??1/B)
• No. frequency points, N 1601
• Frequency step, ?f 4.375MHz (i.e. ?fB/(N-1))
• Max. excess delay, ?max 229.6ns (i.e.
  ?max1/?f)
• Sweeping time, tsw 800ms
• Max. Doppler shift, fd,max 1.25Hz (i.e.
  fd,max1/tsw)

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Measurement Setup (2)

• UWB planar dipole antennas
• Measurement controlled by laptop with LabVIEW via
  GPIB interface
• Calibration performed in an anechoic chamber with
  1m reference separation
• Static environment during recording
• Both large-scale small-scale measurements
• Large-scale different RX positions ? local
  point
• Small-scale 25 (5x5) grid-measurements around
  each local point ? spatial point
• At each spatial point, 30 time-snapshots of the
  channel complex frequency responses are recorded

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Measurement Setup (3)
Propagation Channel
RX antenna
TX antenna
Coaxial Cables
Vector network analyzer (Agilent 8722ES)
Low Noise Amplifier (Miteq AFS5)
Power Amplifier (Agilent 83020A)
Attenuator (Agilent 8496B)
GPIB Interface
Laptop with LabVIEW
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UWB Planar Dipole Antenna
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Measurement Environment

• Measurements in various types of high-rise
  apartments based on several cities in Korea ?
  typical types in Asia countries like Korea,
  Japan, Singapore, Hong Kong, etc.
• 3-bedrooms (Apart1)
• 4-bedrooms (Apart2)
• Both LOS and NLOS configurations
• TX-RX antennas
• Separations up to 20m
• Height 1.25m (with ceiling height of 2.5m)
• TX antenna always fixed in the center of the
  living room
• RX antenna moved around the apartment (i.e. 8-10
  locations)
• 12,000 channel complex frequency responses are
  collected (i.e. 2 apartments x 8 RX local points
  x 25 spatial points x 30 time snapshots ?
  2x8x25x3012,000)

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3-Bedroom Apartment
Grid-Measurement
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4-Bedroom Apartment
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Data Analysis Post-Processing

• All measurement data are calibrated with the
  calibration data measured in anechoic chamber to
  remove effect of measurement system
• Perform frequency domain windowing to reduce the
  leakage problem
• Complex passband IFFT is deployed to transform
  the complex frequency response to complex impulse
  response
• Perform temporal domain binning before extract
  channel parameters

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Channel Model Description

• Large-Scale Parameters
• Path loss and Shadowing
• Frequency Decaying Factor
• Small-Scale Parameters
• Temporal Domain Parameters
• S-V Multipath Channel Parameters
• Small-Scale Amplitude Statistics

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Path Loss and Shadowing

• Path loss (PL) vs. Distance (d)
• d0 1m
• PL0 intercept
• n path loss exponent
• S Shadowing fading parameter
• Perform linear regression to the above equation
  with measured data to extract the required
  parameters

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Path Loss vs. Distance LOS
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Path Loss vs. Distance NLOS
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Frequency Decaying Factor

• Path loss (PL) vs. Frequency (f)
• or

(Method 1)
(Method 2)
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Frequency Decaying Factor LOS
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Frequency Decaying Factor NLOS
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Large-Scale Parameters
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Temporal Domain Parameters

• These parameters were obtained after taking
  frequency domain Hamming windowing, passband IFFT
  temporal domain binning

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S-V Multipath Channel (1)

• Saleh-Valenzuela (S-V) channel model is given by
• L number of clusters lth cluster
• Kl number of MPCs within the
• ak,l multipath gain coefficent of the kth
  component in lth cluster
• Tl delay of the lth cluster
• ?k,l delay of the kth MPC relative to the to
  the lth cluster arrival time

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S-V Multipath Channel (2)

• Cluster arrival times Poisson distribution
• Ray arrival times Poisson distribution
• ? mean cluster arrival rate
• ? mean ray arrival rate

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S-V Multipath Channel (3)

• Average power of a MPC at a given delay, Tl
  ?k,l
• expected value of the power of the first
  arriving MPC
• ? cluster decay factor
• ? ray decay factor

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Cluster Decay Factor, ? LOS
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Cluster Decay Factor, ? NLOS
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Ray Decay Factor, ? LOS
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Ray Decay Factor, ? NLOS
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Cluster Arrival Rate, ? LOS
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Cluster Arrival Rate, ? NLOS
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Ray Arrival Rate, ? LOS
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Ray Arrival Rate, ? NLOS
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Mixture Poisson Distribution

• Fitting the ray arrival times to a mixture of 2
  Poisson distributions similar to 1
• ? mixture probability
• ?1 ?2 ray arrival rates

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Mixture Poisson Distributions LOS
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Mixture Poisson Distributions NLOS
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Number of Clusters
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Number of MPCs per Cluster
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S-V Multipath Channel Parameters
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Small-Scale Amplitude Statistics

• Comparison of empirical path amplitude
  distribution with the following five commonly
  used theoretical distributions
• Lognormal
• Nakagami
• Rayleigh
• Ricean
• Weibull
• The goodness-of-fit of the received signal
  amplitudes is evaluated using Kolmogorov-Smirnov
  (K-S) test Chi-Square (?2) test with 5 and 10
  significance level, respectively.

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Goodness-of-Test LOS
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Goodness-of-Test NLOS
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CDF of Path Amplitude LOS
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CDF of Path Amplitude NLOS
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Small-Scale Amplitude Statistics Parameters

• The results demonstrate that lognormal, Nakagami
  and Weibull fit the measurement data well.
• Parameters of these distributions (i.e. standard
  deviation of lognormal PDF, m-parameter of
  Nakagami PDF and b-shape parameter of Weibull
  PDF) can be modeled by a lognormal distribution,
  respectively
• These parameters are almost constant across the
  excess delay

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Standard Deviation of Lognormal PDF LOS
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Standard Deviation of Lognormal PDF NLOS
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m-Nakagami Parameter LOS
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m-Nakagami Parameter NLOS
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b-Weibull Parameter LOS
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b-Weibull Parameter NLOS
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Variations of Lognormal-? with Delay LOS
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Variations of Lognormal-? with Delay NLOS
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Variations of Nakagami-m with Delay LOS
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Variations of Nakagami-m with Delay NLOS
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Variations of Weibull-b with Delay LOS
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Variations of Weibull-b with Delay NLOS
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Small-Scale Amplitude Statistics Parameters
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Conclusion

• Frequency domain technique UWB measurement
  campaign has been carried out in indoor
  residential environment (high-rise apartments)
  covering frequencies from 3-10 GHz.
• Measurement covered both LOS NLOS scenarios.
• Channel measurement results and parameters which
  characterize both the large-scale and small-scale
  parameters of the channel are reported.

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Reference

1. B. Kannan et. al., Characterization of UWB
   Channels Small-Scale Parameters for Indoor and
   Outdoor Office Environment, IEEE
   802.15-04-0385-00-04a, July 2004.