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Department of Electrical Engineering High-Speed Digital Systems Laboratory. HS DSL. !. Detection of Cellular Activity Within A Defined Space Undergraduate Project – Final Presentation Spring 2008 . Doron Brot Eyal Cimet Supervisor: Yossi Hipsh. The Main Objective.
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Department of Electrical Engineering High-Speed Digital Systems Laboratory HS DSL ! Detection of Cellular Activity Within A Defined SpaceUndergraduate Project – Final PresentationSpring 2008 Doron Brot Eyal Cimet Supervisor: Yossi Hipsh
The Main Objective • Detection and Positioning of Cellular Phone Activity In a Defined Space Where Cellular Use is Unwanted 2
Main System Requirements • Detection and Positioning of Transmitting Cellular Phone • Desired Spatial Resolution & Accuracy: • Required Temporal Resolution: • Compatibility with all Cellular Providers • Detection Regardless of Phone Orientation – Reception of all Linear Polarizations • Ability to Handle Simultaneous Events • Ability to Distinguish Between Original Signal and Multi-path Reflection 3
System Operation Process Angle Measurement Multi-path Filtering Storage Triangulation Sampling Origin Estimation Filtering of Dummy Origins Idle / Trigger Positioning Start
Preliminary Schematic Circular-Polarized Antenna(s) Front-End Overall Band Receiver Power Sensor Sampling Circuit A/D Positioning Algorithm CPU Memory CLK A/D Display Power Sensor Circular-Polarized Omni-Antenna
Angle Measurement • Multi-beam Arrays – MBA: • Antennas Sensitive to Many Spatial Directions Simultaneously, Ideal for Angle Measurement • DifferentialAngle Measurement • Distance From Source Determines SignalStrength
Angle Measurement (Continued) The Differential Measurements from two Consecutive Beams Yields an Estimate of the Angle of Incidence Differential Zone
Origin of Signal is Estimated Based on Angle of Incidence with 2 MBA Antennas and Table Height: Antenna 1 Antenna 2
Multi-path • Reflections Received Simultaneously Must Be Filtered Out Antenna 1 Antenna 2
Possible Solution to Multi-path (1) • Use of RF Absorbing Material Antenna 1 Antenna 2
Possible Solution to Multi-path (2) • Development of Filtering Algorithm for Multi-path Reflections Antenna 1 Antenna 2
Coverage of the Defined Space: Solution Overview Area Split to Lower the Required Dynamic Range
Antenna Setup – 4 MBA’s, each with 6 directional beams Each MBA is Comprised of 9 Narrow-Band Antennas Solution Overview
Solution Overview • Cellular Spectrum • Detection of all Cellular Providers Demands Reception of all Cellular Frequencies in Spectrum
Solution Overview • Front-End Received Power
Detection Regardless of Orientation of Cellular Phone: Circular-polarized Antennas Receive all Linear Polarizations Layout of Circular-polarized Antenna Two Linearly-polarized Antennas Coupled by a 90-Degree Hybrid: Solution Overview Circularly-Polarized Signal Coupler
Final Design Trigger Omni-directional Antenna A/D 12 dB Amp BPF Detector Display Digital Controller (CPU) Front-End Vertical MBA Horizontal MBA 90-Degree Hybrid DCA 12 dB Amp A/D BPF Detector Band 1 A/D Band 2 Frequency Multiplexer Customized Filter to All 9 Bands Band 3 Band 9
Component Survey • IPP-2036 90-Degree Coupler • Frequency Range: 800-2000 MHz • Maximum Input: 150 W • Insertion Loss: < 0.25 dB • Preferred Amplifier: ZJL-4G • Frequency Range: 20-4000 MHz • Typical Gain: 12.4 dB • IP3: 30.5 dB • Noise Figure: 5.5 dB • Maximum Input: 20 dBm
Component Survey • Power Detector – ZX47-40+ • Dynamic Range: -40 to 15 dBm • Response Time: • Output Range: 0.5 – 2.1 VDC • Criteria in Choosing a Detector: • Dynamic Range Fits the System Requirements • Response Time Sufficiently Small compared to Typical Event Period
Component Survey • Sampling Hardware: • Sampler + A/D: Analog Devices AD-7999Resolution: 8 BitSampling Rate: 140 KSpSNo. of Channels: 4Reference: Peak to Peak • DCA: Digitally Controlled AttenuatorNormalizes the Input Power to the Dynamic Range of the Power Detector Based on the Measurement from the Omni-directional Antenna
A Simplified Experiment Demonstrating the Basic Principles of the System, Which Proves that the Suggested Implementation Works Proof of Feasibility
Original Schematic Trigger Omni-directional Antenna A/D 12 dB Amp BPF Detector Display Digital Controller (CPU) Vertical MBA Horizontal MBA Front-End 90-Degree Hybrid DCA 12 dB Amp A/D BPF Detector Band 1 A/D Band 2 Frequency Multiplexer Band 3 Band 9
Number of Antennas – System Strip-Down Successful Detection in One Half of the Room Proves Feasibility
Number of Beams – System Strip-Down 6 Original Beam Directions Simplified Down to 2
The Minimal System for Proof of Feasibility(1) Horizontal MBA Antenna 1 Version Using HF Digitizing Scope Beam 1 12 dB Amp Beam 2 Scope/CPU: 12 dB Amp CH 1 Horizontal MBA Antenna 2 CH 2 CH 3 Beam 1 12 dB Amp CH 4 Agilent Infiniium DSO80204B Beam 2 12 dB Amp
Feasibility Experiment 1 [m] H=1.7 [m] Pos 1 Pos 2 1.8 [m] H=2.6 [m] 2.3 [m] H=2 [m]
The Minimal System for Proof of Feasibility(2) Horizontal MBA Antenna 1 Version Using Power Detectors Beam 1 Power Detector 12 dB Amp Power Detector Beam 2 12 dB Amp Scope CH 1 Horizontal MBA Antenna 2 CH 2 CH 3 Beam 1 Power Detector 12 dB Amp CH 4 Regular Low-Frequency Scope Beam 2 Power Detector 12 dB Amp
Antenna Measurement System Protractor Rotating table Antenna Transmitting antenna Pulse Generator CH 1 CH 2 CH 3 Scope: CH 4
Antenna Measurements Spatial Response of MBA [ dB ] Beam 1 Beam 2
Antenna Measurements Spatial Response of MBA [ dB ] Beam 1 Beam 2
Power Amplifier Measurement System • The 2 Outputs will be compared to measure gain
Amplifier Measurements Amplifier Gain vs. Frequency [ dB ]
A Special Thanks to: • Yossi Hifsch Supervisor and Mentor • Eli Shoshan For all the Support • Bruriya Zochar For all the Help and Supplies • The Entire HS DSL Staff Questions ?