Radar Target Generation and Detection

Design the project process flow as below

1. Configure the FMCW waveform based on the system requirements.

set the range resolution, maximum range, define the target's initial position and velocity,in the project, velocity is constant.

c is speed of light, B_sweep is the sweep bandwidth, T_chirp is the sweep time, fc is the carrier frequency of radar, 77GHz.

• initial position 110m
• initial velocity -20m
• B_sweep = c /(2∗rangeResolution)
• T_chirp =5.5⋅2⋅R_max/c
• Slope=B_sweep/T_chirp

2. Target generation and radar signal processing

2.a Generate the range and velocity of target and simulate its displacement.

2.b For the same simulation loop process the transmit and receive signal to determine the beat signal

3. Perform Range FFT on the received signal to determine the Range

• Implement the 1D FFT on the Mixed Signal
• Reshape the vector into Nr*Nd array.
• Run the FFT on the beat signal along the range bins dimension (Nr)
• Normalize the FFT output.
• Take the absolute value of that output.
• Keep one half of the signal
• Plot the output
• There should be a peak at the initial position of the target

Range FFT output

4. perform the 2D CFAR processing on the output of 2nd FFT to display the target.

• Determine the number of Training cells for each dimension. Similarly, pick the number of guard cells. in my case

%Select the number of Training Cells in both the dimensions.
Tr = 20;
Td = 10;
%Select the number of Guard Cells in both dimensions around the Cell under test (CUT) for accurate estimation
Gr = 6;
Gd = 3;

• Slide the cell under test across the complete matrix. Make sure the CUT has margin for Training and Guard cells from the edges.
• For every iteration sum the signal level within all the training cells. To sum convert the value from logarithmic to linear using db2pow function.
• Average the summed values for all of the training cells used. After averaging convert it back to logarithmic using pow2db.
• Further add the offset to it to determine the threshold.
• Next, compare the signal under CUT against this threshold. If the CUT level > threshold assign it a value of 1, else equate it to 0.

2D CFAR output