Higher Frequency Technologies Under Investigation for Telemetry Saul Ortigoza 661-277-1606 International Consortium for Telemetry Spectrum October 2005

Higher Frequency Technologies Under

Investigation for Telemetry

Saul Ortigoza661-277-1606

International Consortium for Telemetry Spectrum

October 2005

AGENDA

• Introduction

• Technology Development

• Vision

• Conclusions

• Initial foundation of spectrum study efforts based on report by The Mitre Corporation, Bedford, Massachusetts

“A Study of Aeronautical Telemetry Operations in the 3-30 GHz Frequency Band”

• Antenna Alternatives• Doppler Effects• Channel Characteristics• Overcoming Adverse Channel Effects• Advanced Modulation and Coding

∙ 27 suggested work items· 16 work items being addressed by T&E S&T in varying degrees

INTRODUCTION

Next generation of systems testing will require vast amounts of spectrum. The combined coding modulation will provide high spectral efficiency by optimizing the design for the nonlinearly amplified environment.

Combined Coding Modulation

TECHNOLOGY DEVELOPMENTImprove EfficiencyImprove Efficiency

-70 -60 -50 -40 -30 -20 -10

Po

wer

spe

ctru

m (

dB

c)

-1.5 -1 -0.5 0 0.5 1 1.5 Frequency offset (bit rate=1)

PCM/FM FQPSK-B MHCPM CCM

SHF Channel Modeling for Aeronautical Telemetry

Findings to Date:

Preliminary data indicate that multipath and other signal path characteristics demonstrate large magnitude signal fades at rapidly changing rates compared to conventional L and S band operations. Full testing should be completed in 2005.

Channel Sounding/Channel Transfer Function

TECHNOLOGY DEVELOPMENTAugment Higher FrequenciesAugment Higher Frequencies

SHF Channel Modeling

Received Spectrum

CHANNEL TRANSFER FUNCTION

Transmitted Spectrum-35-30-25-20-15-10-50510

-8 -6 -4 -2 0 2 4 6 8Frequency (MHz), relative to carrier

|H(ej )|2 (

dB

)

Atmospheric Absorption

up to30km

Airplane

Cloudheight2-4km

Cloud and Fog

Rain Attenuation

Scintillation

Estimation of Microwave Power Margin Losses Due to Earth’s Atmosphere and Weather in the Frequency Range of 3-30 GHz

Findings to Date:The total propagation losses due to gaseous absorption, rain attenuation, cloud attenuation and scintillation/multipath (except the free space loss) for a 100-km path with 3.1° elevation angle are:

- Location A; 12.8 dB (12 GHz) and 49.2 dB (24 GHz) - Location B; 11.0 dB (12 GHz) and 39.2 dB (24 GHz) - Location C; 17.4 dB (12 GHz) and 67.6 dB,(24 GHz)

Location C Case Study

Shows that for a 50-km path with elevation angle of 6.2 degrees, total propagation loss at 12.0 GHz at 1.0% of time exceeded is 156.3 dB, which is 8.28 dB more than the free space loss alone.

Propagation Losses



Antenna Interference

Beam SteeringInvestigates transmitting techniques designed to reduce selective fading seen during aeronautical testing incorporating phase shifters to steer nulls.

Findings: Proof of concept during static test program, future flight test program being designed.

Explore the Applicability of Space-Time Coding to Aeronautical Telemetry Applications

Findings: Successful flight test of STC encoder. Transitioned to Central Test & Evaluation Investment Program (CTEIP).

Antenna patterns

Space-TimeDecoder

Channel

Space-TimeEncoder

30

210

60

240

90

270

120

300

150

330

180 0

30

210

60

240

90

270

120

300

150

330

180 0

30

210

60

240

90

270

120

300

150

330

180 0

Null

Antenna 2

Antenna 1

A Spectrally Efficient, High Data Rate Telemetry System for Operation under Adverse Channel Conditions in the SHF (3-30 GHz) Band

Findings: Advanced Orthogonal Frequency Division Multiplexing (AOFDM) is well suited to aeronautical telemetry with ability to handle high Doppler rates.

Advance Modulations


OFDM-Based Modulator


Cross-Channel (Turbo)

Encoder

Input Bit

Stream

OFDM-Based Demodulator


Diversity Combiner

(Iterative) Decoder

Output Bit

Stream



Cross-Channel (Turbo)

Encoder

Input Bit

Stream



Diversity Combiner

(Iterative) Decoder

Output Bit

Stream

Antenna Tracking

X-Band Tracking

Conduct flight test to in a close range, high-dynamic environment to demonstrate the ability to track with a smaller beamwidth.


Phased-Array AntennaDevelop autonomous neural network and low complexity antenna pointing algorithms which improve the pointing accuracy and pointing speed of ground antennas utilized for T&E.

X-Band smaller beam width(1° vs 4° for S-Band): Requires increased tracking precision

S-Band beam width = 4.0

X-Band beam width = 1

10-km

80-m

Antenna

Aircraft formation

RF MEMSUsing Micro Electromechanical Systems (MEMS) Radio Frequency (RF) elements provide a low cost, low profile, multifunction phase-array antenna. The proposed system will allow for selection between four different antenna beams and two operational frequencies (4.7 GHz and 7.5 GHz).

Software Defined Antenna


Special Session at ITCWednesday 26 Oct 0830-1130

ITC 2005 Technical ProgramSESSION 10 - T&E / S&T Spectrum Efficient Technology (SPECIAL SESSION)

SS10-1 “A Robust Telemetry Link - Advanced OFDM,” Scott Darden, Jet Propulsion Laboratory, JPLFrequency diversity combing with OFDM (based on commercial 802.11 wireless) Flight test results will be presented.

SS10-2 “Antenna Tracking Improvements with Focal Plane Array using advanced algorithms,” Dr Ryan Mukai,JPL Development of a prototype focal plane array feed for a parabolic antenna integrating advanced algorithms for improved antenna and multiple target tracking performance.

SS10-3 “BYU Telemetry Lab projects supporting Aeronautical Telemetry and Spectrum Augmentation,” Dr Michael Rice, Brigham Young UniversityA summary of experiments using airborne transmitters with multiple antenna transmission and channel sounding transmission.

SS10-4 “Software Defined Antenna,” Dr Franco DeFlaviis, University of California at IrvineUtilization of RFMEMs in a PCB substrate facilitates the development of a software defined antenna. Concept demonstration results will be shown with switches for band reconfiguring between 4.7 and 7.5 GHz.

SS10-5 “Beamformer Antenna for Launch Vehicles, Missiles, and Rockets,” Dan Mullinix- NASA Wallops Flight FacilityNovel true time mechanical delay lines are used to form a computer tracking beam from an array of patch antennas on a dynamic launch vehicle. Purpose is to obtain transmit antenna gain for relay of signals from ELV through TDRSS.

SS10-6 “X-Band Tracking,” Moises Pedroza, White Sands Missile RangeResults of successful aircraft tracking by a modified mobile ground antenna at X-band frequency will be presented.

Details presented by Principle Investigators!!!

SPECTRUM EFFICIENT TECHNOLOGYVisionVision

Future• Operate in harmonized global frequency band

• Autonomous/adaptive spectrum use without bands

• Directional beam steering antenna radiation pattern

• Power: Aircraft 5 to 10 Watts, Orbital 25 Watts

• Tunable bandwidth

• Networked

• Antenna frequency variability

• Range distance: Rangeless Range

CONCLUSIONS

• Exciting innovative approaches are ongoing– Developing capabilities to augment higher

frequencies– Technologies show potential – We can do it!!!

T&E/S&T – Where Innovation Becomes Reality

Documents

Higher Frequency Technologies Under Investigation for Telemetry Saul Ortigoza 661-277-1606 International Consortium for Telemetry Spectrum October 2005