RF Signal Reflection Experiments

Phase 3/4 (100%)

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The Insight

Ambient RF signals reflect off objects in the environment. By processing these reflections with coherent multi-channel receivers, we can extract bistatic range and Doppler shift information — an interesting signal processing challenge.

Quick Facts

What This Is

An experimental signal processing project exploring how to analyze reflections of ambient radio signals. The system uses coherent multi-channel RF data to study bistatic geometry and Doppler effects.

Core Principles

Signal Reflection and Processing:

• Ambient Transmitters: FM radio, DVB-T, or cellular signals serve as convenient RF sources
• Bistatic Geometry: Separates transmitter and receiver — objects reflect signals toward the receiver
• Cross-Correlation Processing: Correlates reference channel (direct signal) with surveillance channels (reflections)
• Range-Doppler Mapping: Extracts time-delay and frequency-shift information from reflections

Signal Processing Chain:

1. Reference Signal Capture: Acquire clean direct signal from transmitter
2. Reflection Channel Processing: Receive signals containing reflections
3. Adaptive Interference Cancellation: Remove direct signal and static multipath
4. Cross-Correlation: Extract reflection signatures via time-delay analysis
5. Doppler Analysis: Apply FFT to study frequency shifts from motion
6. Detection Processing: Threshold analysis and signal extraction

Why This Approach:

• Cost-Effective: Uses existing RF infrastructure for experiments
• Educational: Practical exploration of bistatic radar concepts and signal processing techniques

Current Status

Clean, stable codebase for processing multi-channel RF reflections. Currently focused on establishing a solid signal processing foundation with single-channel experiments.