AWR1642BOOST: 2D FFT Results - symmetric errors

Hi,

Could you post your configuration and code (pseudo) of the script?

Regards,

Jitendra

Sure!

The configuration is shown below. And the matlab pseudo code is something like:

clc;
clear all;
close all;
%% parameter setting
% constant parameters
c = physconst('LightSpeed');% Speed of light in air (m/s)
fc = 77e9;% Center frequency (Hz)
lambda = c/fc;
Rx = 4;
Tx = 2;

% configuration parameters
Fs = 4*10^6;
sweepSlope = 21.0017e12;
samples = 128;
loop = 255;
% loop = 128;
Tc = 120e-6; %us
fft_Rang = 128;
fft_Vel = 256;
data_each_frame=samples*loop*2*Rx;
%% Creat grid table
freq_res = Fs/fft_Rang;% range_grid
freq_grid = (0:fft_Rang-1).'*freq_res;
rng_grid = freq_grid*c/sweepSlope/2;% d=frediff_grid*c/sweepSlope/2;

% velocity_grid
dop_grid = fftshiftfreqgrid(fft_Vel,1/Tc); % now fs is equal to 1/Tc
vel_grid = dop_grid*lambda/2; % unit: m/s, v = lamda/4*[-fs,fs], dopgrid = [-fs/2,fs/2]

w = [-180:4:180]; % angle_grid
agl_grid = asin(w/180)*180/pi; % [-1,1]->[-pi/2,pi/2]

%% read file
data=readDCA16xx('adc_data.bin');
data_all=reshape(data,size(data,1)*size(data,2),[]); % reshape 4 channels into 1
for i=1:10 % 1:end frame
% seperate each frame and reshape the raw data to foramt [samples,antennas,chirps]
Framedata(:,i)=data_all(((i-1)*data_each_frame+1):i*data_each_frame);
Frame_loop(:,:,i)=reshape(Framedata(:,i),samples*4,[]);
Frame_loop_chirp1(:,:,i)=Frame_loop(:,1:2:end,i);
Frame_loop_chirp2(:,:,i)=Frame_loop(:,2:2:end,i);

for jj=1:loop
Frame_loop_chirp1_Rx(:,:,jj,i)=reshape(Frame_loop_chirp1(:,jj,i),[samples Rx]);
Frame_loop_chirp2_Rx(:,:,jj,i)=reshape(Frame_loop_chirp2(:,jj,i),[samples Rx]);
end
Xcube_chirp1=permute(Frame_loop_chirp1_Rx(:,:,:,i),[1 2 3]);
Xcube_chirp2=permute(Frame_loop_chirp2_Rx(:,:,:,i),[1 2 3]);

Nr=size(Xcube_chirp1,1); %%% length of Chirp
Ne=size(Xcube_chirp1,2); %%% # of receiver
Nd=size(Xcube_chirp1,3); %%% # of chirp loop
% Range FFT
for ri=1:Ne
for rj=1:Nd
win_rng = Xcube_chirp1(:,ri,rj);
Rangedata(:,ri,rj)=fft(win_rng,fft_Rang);
end
end
% Doppler FFT
for di=1:Ne
for dj=1:Nr
win_dop =reshape(Rangedata(dj,di,:),Nd,1).* 1;%hann(Nd);
DopData(dj,di,:)=fftshift(fft(win_dop,fft_Vel));
end
end
% plot 2DFFT
figure()
mesh(vel_grid,rng_grid,20*log10(abs(squeeze(DopData(:,1,:)))));
view(0,90)
axis([-10,10,0,28])
title('Range-doppler plot for Rx1')
xlabel('doppler')
ylabel('Range')
end:

The read_DCA16xx function is :

%%% This script is used to read the binary file produced by the DCA1000
%%% and Radar Studio
%%% Command to run in Matlab GUI - readTSW14xx('<ADC capture bin file>')
function [retVal] = readDCA16xx(fileName)
%% global variables
% change based on sensor config
%----------------------------------------------------------------------
numADCBits = 16; % number of ADC bits per sample
numLanes = 2; % do not change. number of lanes is always 4 even if only 1 lane is used. unused lanes
isReal = 0; % set to 1 if real only data, 0 if complex dataare populated
% with 0
%----------------------------------------------------------------------
%% read file and convert to signed number
% read .bin file
fid = fopen(fileName,'r');
adcData = fread(fid,'uint16');
% compensate for offset binary format
adcData = adcData-2^15;
% if 12 or 14 bits ADC per sample compensate for sign extension
if numADCBits ~= 16
l_max=2^(numADCBits-1)-1;
adcData(adcData>l_max) = adcData(adcData>l_max) - 2^numADCBits;
end
fclose(fid);
%% organize data by LVDS lane
% reshape data based on four samples per LVDS lane
len_total = length(adcData);
fix_adc_len = len_total - rem(len_total, numLanes*4);
adcData = reshape(adcData(1:fix_adc_len), numLanes*4, []);
% for real only data
if isReal
%each LVDS lane contains two samples from each RX
rxSample1 = adcData([1,2,5,6],:);
rxSample2 = adcData([3,4,7,8],:);
% interleave the first sample set and the second sample set
adcData = reshape([rxSample1;rxSample2], size(rxSample1,1), []);
%for complex data
else
% combine real and imaginary parts of complex number
adcData = adcData([1,2,5,6],:) + sqrt(-1)*adcData([3,4,7,8],:);
end
%% return receiver data

retVal = adcData;

Thanks,

William