Hi,
Our customer is having a feedback as below:
In the post processing configuration that show up after the chirp regeneration, I saw the FFT plot with the distance. Then I tried to take the (.bin) file date and process it in MATLAB to get the same figure out from the file. However, I noticed that there are shift in the main peak towards the lower range. For example, my target in the post processing results from the mm wave studio was at 10 meter but in the file that I processed in MATLAB it was at 6 meter.
Mainly, I followed the guideline in the manual that give how to extract the data from the DCA1000 board as in the attachment pages (16 and 17), and then I want the first receiver data so I just put the following MATLAB command at the end of the code in the manual to take the results:
test=adcData(1,1:end); % one chirp profile from the 1st Rx
N=numADCSamples*1; % Number of Samples in the chirp
fs = 10*10^6 ; %% Fs in MHz as in the configuration window
time_step = 1/fs;
time = 0:time_step:(N-1)*time_step;
f = linspace(-fs/2,fs/2,N);
fft_signal = fft(test(1,:),N);
Px = 10*log10(fft_signal.*conj(fft_signal));
%% Plotting in Range
c=3*10^8;
K=1; % air medium
v=c/sqrt(K); % speed of light in medium
B=1.85*10^9; % Bandwidth 1.85 GHZ
T=150*10^-6; % 150us chirp length
S = B / T; % Chirp slope Rate
R = (f .* v) ./(S); % FMCW range equation
figure (1);
plot(R(N/2+1:end),(Px(N/2+1:end)-max(Px)),'b','LineSmoothing','on','LineWidth',1);
grid on
title('Power Spectrum')
xlabel('Range (m)')
ylabel('dB')
1. Please let me know if there is another way to deal with the raw data to generate the same results as the mm wave studio .
2. In the FFT 1D plot, how I can improve the resolution of the curve more. I tried to increase the ADC sampling to 1024 and it still not good enough. I increased the ADC sampling to 4096 and the sampling rate to 30000K and it was not showing that in the calculated parameters. So I guess the maximum is 1024. Is there any other was to improve the curve resolution.
