May 7 2004 doc IEEE 802 15 04

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May 7, 2004 doc. : IEEE 802. 15 -04 -0215 -00 -004 a Project:

May 7, 2004 doc. : IEEE 802. 15 -04 -0215 -00 -004 a Project: IEEE 802. 15 Study Group for Wireless Personal Area Networks (WPANs) Submission Title: [Ultra-Wideband Channel Model for Farm/Open-Area Applications] Date Submitted: [11 May, 2004] Source: [Shahriar Emami, Celestino A. Corral, Gregg Rasor]: Company 1 [Freescale Semiconductor], Address [8000 W. Sunrise Blvd. , Plantation, FL 33322], Voice: [(954) 723 -3854], FAX: [(954) 723 -3883] Re: [Channel Model Submission] Abstract: [An ultra-wideband channel model for open area/farm applications is submitted. The channel model is based on ray tracing that captures signal descriptors including frequencies. The rationale behind the channel model is developed and presented in support of the presentation. ] Purpose: [An understanding of the open area outdoor environment for ultra-wideband (UWB) signal coverage is needed for 802. 15 TG 4 a. This channel model should assist in predicting UWB range and proper signal design for open area applications. ] Notice: This document has been prepared to assist the IEEE P 802. 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 P 802. 15. Contribution 1 Shahriar Emami, Freescale Semiconductor

May 7, 2004 doc. : IEEE 802. 15 -04 -0215 -00 -004 a Ultra-Wideband

May 7, 2004 doc. : IEEE 802. 15 -04 -0215 -00 -004 a Ultra-Wideband Channel Model for Farm/Open-Area Applications Understanding UWB Propagation in Open Areas Subject to Selected Environmental Factors Shahriar Emami, Celestino A. Corral, Gregg Rasor Freescale Semiconductor The presenters wish to acknowledge the support and contributions of: • Glafkos Stratis/Motorola • Salvador Sibecas/Motorola Contribution 2 Shahriar Emami, Freescale Semiconductor

May 7, 2004 doc. : IEEE 802. 15 -04 -0215 -00 -004 a Outline

May 7, 2004 doc. : IEEE 802. 15 -04 -0215 -00 -004 a Outline • Ultra-wideband Outdoor Channel Model Status • Special Considerations – Approach – Frequency Selection – Simulation Setup • Simulation Results – Ground conditions – Channel Impulse Response and Ray Statistics – Coverage • Summary and Conclusions • Proposed Continuing Investigations Contribution 3 Shahriar Emami, Freescale Semiconductor

May 7, 2004 doc. : IEEE 802. 15 -04 -0215 -00 -004 a Channel

May 7, 2004 doc. : IEEE 802. 15 -04 -0215 -00 -004 a Channel Model Status We shall show this in simulation • Prior Efforts: – Two-ray UWB path loss model: • S. Sato and T. Kobayashi, “Path-loss exponents of ultra wideband signals in line-of-sight environments, ” IEEE 802. 15 -04 -0111 -00 -004 a, March 2004. – Deterministic UWB channel model based on ray tracing approach: • B. Uguen, E. Plouhinec, Y. Lostanlen, and G. Chassay, “A deterministic ultra wideband channel modeling, ” 2002 IEEE Conf. Ultra Wideband Syst. Tech. We use approach considered here Contribution 4 Shahriar Emami, Freescale Semiconductor

May 7, 2004 doc. : IEEE 802. 15 -04 -0215 -00 -004 a Special

May 7, 2004 doc. : IEEE 802. 15 -04 -0215 -00 -004 a Special Considerations • Farm areas feature isolated clusters of scatterers • Material properties may change with frequency. (For our simulations, we assume material properties constant over frequency. ) In addition, the outdoor channel is subject to environmental changes – Seasonal changes (snow, ice, etc. in some regions) – Rain/wet conditions Contribution 5 Shahriar Emami, Freescale Semiconductor

May 7, 2004 doc. : IEEE 802. 15 -04 -0215 -00 -004 a Different

May 7, 2004 doc. : IEEE 802. 15 -04 -0215 -00 -004 a Different Absorption Regions Frequency Range Of Interest Conduction Dipole and We assume no dielectric changes over frequency Ionic Relaxation Space Charge Polarization -6 -4 Log frequency (Hz) -2 0 Atomic Electronic Absorption 2 4 6 8 10 60 Hz R. C. Dorf (Ed. ), The Electrical Engineering Handbook, 2 nd Ed. , Boca Raton, Florida: CRC Press, 1997. Contribution 6 12 14 16 18 Dielectric practically constant over frequency range of interest. Shahriar Emami, Freescale Semiconductor

May 7, 2004 doc. : IEEE 802. 15 -04 -0215 -00 -004 a Approach

May 7, 2004 doc. : IEEE 802. 15 -04 -0215 -00 -004 a Approach • Use deterministic 3 -D ray tracing simulator - Employs – geometric optics – uniform theory of diffraction (UTD) – Generates • Received signal strength • Ray statistics (path length/delay) • Signal descriptors include frequency, polarization, etc. • UWB channel sounding is achieved by superposition of NB channel sounding - Conventional channel sounding - FCC emissions mask scaled channel sounding M. F. Iskander and Z. Yun, “Propagation prediction models for wireless communication systems, ” IEEE Trans. Microwave Theory Tech. , vol. 50, pp. 662— 673, March 2002. Contribution 7 Shahriar Emami, Freescale Semiconductor

May 7, 2004 doc. : IEEE 802. 15 -04 -0215 -00 -004 a Frequency

May 7, 2004 doc. : IEEE 802. 15 -04 -0215 -00 -004 a Frequency Selection Energy of band concentrated in high band frequency 0 d. Bm -14. 8 3. 10 4. 24 5. 34 6. 72 8. 64 Channel Sounding 10. 6 -11. 4 -11. 2 3. 10 4. 24 5. 34 6. 72 8. 64 10. 6 “High-Pass” Sounding Energy of band concentrated in -11. 2 geometric center -12. 8 -11. 4 frequency -13. 8 -14. 8 3. 62 Contribution -13. 8 -12. 8 8 4. 76 5. 99 7. 62 9. 57 “Band-Pass” Sounding Shahriar Emami, Freescale Semiconductor

May 7, 2004 doc. : IEEE 802. 15 -04 -0215 -00 -004 a Simulation

May 7, 2004 doc. : IEEE 802. 15 -04 -0215 -00 -004 a Simulation Set-Up 3 -D omni antenna pattern used Omni pattern assumed at all frequencies omni antenna above house Provides worst-case delay modeling omni antenna near ground Farm area consists of two-story wood home and metal grain silo. Ground is not flat; has slight variations in height. Contribution • Receiver grid placed around home, 200 m X 200 m • Receiver spacing was 4 m X 4 m • Receiver height was at 1. 3 m • For omni antenna above house, antenna was at 12. 5 m height • For omni antenna near ground, antenna was at 1. 5 m height. 9 Shahriar Emami, Freescale Semiconductor

May 7, 2004 doc. : IEEE 802. 15 -04 -0215 -00 -004 a Coverage

May 7, 2004 doc. : IEEE 802. 15 -04 -0215 -00 -004 a Coverage Results Lowest Frequency – 4. 24 GHz Dry soil Wet soil and wet roof 200 m TX power = 0 d. Bm 200 m Contribution TX power = 0 d. Bm • Highest level -64. 4 d. Bm • Highest level -66. 5 d. Bm • Shadowing due to metal silo evident • Smoother ripple closer to antenna • Ripple due to two-ray phenomenon evident • Impact of roof more significant 10 Shahriar Emami, Freescale Semiconductor

May 7, 2004 doc. : IEEE 802. 15 -04 -0215 -00 -004 a Coverage

May 7, 2004 doc. : IEEE 802. 15 -04 -0215 -00 -004 a Coverage Results Full Frequencies -- Channel Sounding Dry soil Wet soil TX power = 0 d. Bm Contribution TX power = 0 d. Bm • Highest level -64. 4 d. Bm • Highest level -66. 5 d. Bm • Some deep fades are eliminated, others softened • Higher signals closer to antenna • Ripple due to two-ray phenomenon still evident, although smooth ripple closer • Shadowing due to silo and roof still significant Dry/wet conditions are fairly similar 11 Shahriar Emami, Freescale Semiconductor

May 7, 2004 doc. : IEEE 802. 15 -04 -0215 -00 -004 a Coverage

May 7, 2004 doc. : IEEE 802. 15 -04 -0215 -00 -004 a Coverage “High-pass” and “Band-pass” Sounding Dry soil TX antenna placed at 1. 5 m height and at the side of the house • High-pass sounding • Band-pass sounding • Highest level -61. 8 d. Bm • Highest level -60. 2 d. Bm • Significant shading by house as well as silo • Range for -75 d. Bm sensitivity is quite low, on the order of 15 m. High-pass and bandpass sounding are similar Contribution 12 Shahriar Emami, Freescale Semiconductor

May 7, 2004 doc. : IEEE 802. 15 -04 -0215 -00 -004 a Simulation--Validation

May 7, 2004 doc. : IEEE 802. 15 -04 -0215 -00 -004 a Simulation--Validation • Powers in the different frequency bands are summed together • Received power profile in agreement with the work of Sato and Kobayashi TX antenna placed at 1. 5 m height and at the side of the house Contribution 13 Shahriar Emami, Freescale Semiconductor

May 7, 2004 doc. : IEEE 802. 15 -04 -0215 -00 -004 a Simulation

May 7, 2004 doc. : IEEE 802. 15 -04 -0215 -00 -004 a Simulation Results—Ground Conditions • Ground conditions (wet or dry) has almost no impact on received signal power or delay spread. • Subsequent simulations were assuming dry conditions Contribution 14 Shahriar Emami, Freescale Semiconductor

May 7, 2004 doc. : IEEE 802. 15 -04 -0215 -00 -004 a Simulation

May 7, 2004 doc. : IEEE 802. 15 -04 -0215 -00 -004 a Simulation Results— Channel Impulse Response • CIR is similar to two-ray model. Contribution 15 Shahriar Emami, Freescale Semiconductor

May 7, 2004 doc. : IEEE 802. 15 -04 -0215 -00 -004 a Simulation

May 7, 2004 doc. : IEEE 802. 15 -04 -0215 -00 -004 a Simulation Results— Channel RF Parameters Table I. 90 percentile received power Scenario Received Power (d. Bm) Table II. 90 percentile delay spread Scenario A B -83 -74 Scenario A B Mean Excess Delay (ns) RMS Delay (ns) 380 365 19 26 - Scenario A: transmit antenna is placed on the top of farm house - Scenario B: transmit antenna is placed along the side of the house Contribution 16 Shahriar Emami, Freescale Semiconductor

May 7, 2004 doc. : IEEE 802. 15 -04 -0215 -00 -004 a Simulation

May 7, 2004 doc. : IEEE 802. 15 -04 -0215 -00 -004 a Simulation Results—Ray Statistics • Statistics of the two rays are found to be Rayleigh distributed. Contribution 17 Shahriar Emami, Freescale Semiconductor

May 7, 2004 doc. : IEEE 802. 15 -04 -0215 -00 -004 a Simulation

May 7, 2004 doc. : IEEE 802. 15 -04 -0215 -00 -004 a Simulation Results—Channel Sounding • Channel (uniform) sounding leads to larger received power as compared to constrained channel (FCC-mask compliant) sounding. FCC-mask complaint Uniform sounding Over 10 d. B difference Contribution 18 Shahriar Emami, Freescale Semiconductor

May 7, 2004 doc. : IEEE 802. 15 -04 -0215 -00 -004 a Simulation

May 7, 2004 doc. : IEEE 802. 15 -04 -0215 -00 -004 a Simulation Results— “High-pass” or “Band-pass” Sounding • “Band-pass” sounding results in +1 d. B higher received power compared to “highpass” sounding. High-pass Contribution High-pass and bandpass sounding are similar Band-pass 19 Shahriar Emami, Freescale Semiconductor

May 7, 2004 doc. : IEEE 802. 15 -04 -0215 -00 -004 a Simulation

May 7, 2004 doc. : IEEE 802. 15 -04 -0215 -00 -004 a Simulation Results—Coverage Table III. % grid Coverage, if the receiver sensitivity is -90 d. Bm. Coverage (%) Contribution 20 100 x 100 30 x 30 85 85 Shahriar Emami, Freescale Semiconductor

May 7, 2004 doc. : IEEE 802. 15 -04 -0215 -00 -004 a Simulation

May 7, 2004 doc. : IEEE 802. 15 -04 -0215 -00 -004 a Simulation Results—Channel Model CM 1* CM 2* CM 3* I mean 1. 4092 e 007 3. 1052 e 008 -5. 8368 e 009 Q mean -1. 8287 e 008 5. 9910 e 009 -4. 2345 e 009 22. 654 35. 491 251. 53 3. 5565 5. 0733 MED (ns) RMS Delay (ns) 20 * The transmitter receiver separation distances are 5, 15 and 75 meters in CM 1, CM 2 and CM 3, respectively. Contribution 21 Shahriar Emami, Freescale Semiconductor

May 7, 2004 doc. : IEEE 802. 15 -04 -0215 -00 -004 a Summary

May 7, 2004 doc. : IEEE 802. 15 -04 -0215 -00 -004 a Summary and Conclusions UWB Ray Tracing: • Ray tracing with realistic antennas and appropriate material properties was implemented. • Analyses included all ray statistics/parameters (ray physics). • CIR of UWB channel is found by superposition of CIR of individual bands with appropriate power weighting. Channel Modeling Results: • 5 -band approach is adequate for predicting outdoor coverage in farm scenario as verified by prior two-ray modeling. • “High-pass” sounding yields most conservative results. • RF parameters appear almost insensitive to ground material/conditions. • 100 m range achievable with -90 d. Bm RX sensitivity. • CIR is similar to that of two-ray model. RMS delay depends on location of antenna and statistics of the rays. • Two-ray statistics are verified to have Rayleigh distribution. Contribution 22 Shahriar Emami, Freescale Semiconductor

May 7, 2004 doc. : IEEE 802. 15 -04 -0215 -00 -004 a Ongoing

May 7, 2004 doc. : IEEE 802. 15 -04 -0215 -00 -004 a Ongoing Investigations • Incorporate uplink simulations. • Alternative frequency domain based approach. • Measurement and verification. Contribution 23 Shahriar Emami, Freescale Semiconductor

May 7, 2004 doc. : IEEE 802. 15 -04 -0215 -00 -004 a Back-up

May 7, 2004 doc. : IEEE 802. 15 -04 -0215 -00 -004 a Back-up Slides Contribution 24 Shahriar Emami, Freescale Semiconductor

May 7, 2004 doc. : IEEE 802. 15 -04 -0215 -00 -004 a Material

May 7, 2004 doc. : IEEE 802. 15 -04 -0215 -00 -004 a Material Properties Pellat-Debye Equations for loss at single relaxation time. Real permittivity exhibits lowpass frequency response. Imaginary part exhibits band-pass response. Regions can be separated for different relaxation times. Temperature effects are not modeled, but only affected by change in density of dielectric material. Reference Data for Engineers: Radio, Electronics, Computer & Communications, 8 th Ed. , Carmel, Indiana: SAMS, Prentice-Hall Computer Pub. , 1993. Contribution 25 Shahriar Emami, Freescale Semiconductor