939 CFAR Radar Detector
939 : CFAR Radar Detector
- Author: Illamparuthi
- Description: Low-area CA-CFAR hardware accelerator for adaptive radar target detection using sliding window noise estimation
- GitHub repository
- Open in 3D viewer
- Clock: 10000000 Hz
How it works
This project implements a CA-CFAR (Cell Averaging Constant False Alarm Rate) radar detector with a buzzer alert output.
Radar samples are provided through the input bus ui_in[7:0]. These samples represent signal amplitudes from a radar or sensing system such as Ground Penetrating Radar (GPR) or object detection sensors.
The CFAR algorithm processes the samples using a sliding window structure:
Training Cells | Guard Cells | CUT | Guard Cells | Training Cells
Training cells estimate the background noise level. Guard cells prevent the target signal from influencing the noise estimate. The Cell Under Test (CUT) is the sample being evaluated for detection.
The noise level from the surrounding training cells is averaged and used to generate a dynamic threshold:
threshold = 2 × average_noise
If the CUT value exceeds this threshold, a target detection event is generated.
Outputs of the design:
uo_out[0]– CFAR detection signaluo_out[1]– buzzer output signal
When a detection occurs, the buzzer module produces an alert signal indicating the presence of a detected target.
How to test
The design can be simulated using Icarus Verilog.
Compile the design:
iverilog -o sim src/*.v test/tb.v
Run the simulation:
vvp sim
Open the waveform viewer:
gtkwave tb.fst
Example radar input sequence used for testing:
10 11 9 10 12 11 10 200 11 10
In this sequence, the value 200 represents a strong reflection and should exceed the CFAR threshold. When this happens, the detection output (uo_out[0]) becomes high and the buzzer output (uo_out[1]) is activated.
External hardware
No external hardware is required.
The project is fully digital and designed to run inside the TinyTapeout ASIC environment. For real-world applications, the output pins could be connected to external devices such as a buzzer, LED indicator, or radar front-end module.
IO
| # | Input | Output | Bidirectional |
|---|---|---|---|
| 0 | Radar sample bit 0 | CFAR detection output | Unused |
| 1 | Radar sample bit 1 | Unused | Unused |
| 2 | Radar sample bit 2 | Unused | Unused |
| 3 | Radar sample bit 3 | Unused | Unused |
| 4 | Radar sample bit 4 | Unused | Unused |
| 5 | Radar sample bit 5 | Unused | Unused |
| 6 | Radar sample bit 6 | Unused | Unused |
| 7 | Radar sample bit 7 | Unused | Unused |