AWR2243: Problems about modifying the Beamforming Angle Matrix under the Beamforming mode

Hi Katherine,

1) Can you let us know which example code you are referring to?

2) "anglesToSteer=[-30:2:30]" Can you let us know what this actually implements on the device. Are you moving on steps of 2 degrees? The device has a single step of 5.625 degrees

3) What is the percentage of error you are observing in both the cases?

Thanks,

Pradipta.

1) The data collected was BF data, and Cascade_Configuration_Basic.lua, Cascade_TxBF_dataCapture (SMRR), Cascade_Capture.lua were run respectively.

2) anglesToSteer=[-60:1:60], I wanted to achieve angle scanning from -60° to 60° with a step of 1°. For The single step of the device is 5.625°. First of all, "anglesToSteer=[-30:2:30]" is the example code, and on page 18 of Imaging Radar Using Cascaded mmWave Sensor Reference Design.pdf, the sentence 'The TX beam is steering within [–60 60] with step size of 0.5 degree' suggests that the step can reach 0.5°. So, my understanding is the scanning angle of BF is not of the same physical quantity as the 5.625° that you mentioned?

3) After testing, I found that if anglesToSteer*nchirp_loops<2048 (they were all parameters in USRR/LRR/SMRR), the same situation as above would not appear. For example, under the frame based steering mode, if the chirp value of every angle is set at 64, then the maximum scan angle should be less than 32. So, what is the reason for this? The manual doesn't seem to have mentioned it.

In addition, I am currently doing a comparison between BF and MIMO modes. Could you share the code for Figure 19 in Imaging Radar Using Cascaded mmWave Sensor Reference Design.pdf?

Hi,           

    The step size of the Scan will define the number of scan angles and will then define the resolution possible between 2 objects. The default configuration is frame based steering. This is governed by the maximum frame size which TDA can support form capture perspective. This detail is listed in the cascade user guide. I would recommend to tune the

params.nchirp_loops = nchirp_loops; % Number of chirps per frame
params.Num_Frames = Num_Frames; % number of frames to collect data 

In the profile which you plan to use to get the desired resolution at desired range in desired scan window.

Regards

Hello,

Thank you for your reply.

As you mentioned, "This is governed by the maximum frame size which TDA can support form capture perspective. This detail is listed in the cascade user guide". Where could I find it in the cascade user guide? I looked through the cascade user guide but I didn't find it.

Besides, my configuration is set as you suggested. It's as follows:

function [params] = chirpProfile_TxBF_USRR()

% TI cascade board antenna configurations

platform = 'TI_4Chip_CASCADE';

%% fixed antenna ID and postion values for TI 4-chip cascade board. Should not be changed if user is based on TI board
TI_Cascade_TX_position_azi = [11 10 9 32 28 24 20 16 12 8 4 0 ];%12 TX antenna azimuth position on TI 4-chip cascade EVM
TI_Cascade_TX_position_ele = [6 4 1 0 0 0 0 0 0 0 0 0];%12 TX antenna elevation position on TI 4-chip cascade EVM
TI_Cascade_Antenna_DesignFreq = 76.8; % antenna distance is designed for this frequency
speedOfLight = 3e8;
params.Tx_Ant_Arr_BF = [ 12:-1:4]; %TX channel IDs to use for beamforming; all 16 RX channels are enabled by default
params.D_TX_BF = TI_Cascade_TX_position_azi(params.Tx_Ant_Arr_BF); %TX azimuth antenna coordinates in unit of half lamda

% params.D_RX = D_RX; %RX channel azimuth location in the unit of half wavelength
params.RadarDevice=[1 1 1 1]; %set 1 all the time
params.Rx_Elements_To_Capture = 1:16; %All Rx


%% define what angles to steer in TX beamforming mode
params.anglesToSteer=[-60:1:60]; % angles to steer in TX beamforming mode, in unit of degrees
% params.anglesToSteer = -20*ones(1,5);
params.NumAnglesToSweep = length(params.anglesToSteer);

%% chirp/profile parameters
nchirp_loops = 64;
Num_Frames = 5;
params.Start_Freq_GHz = 77; % starting fequency for chirp, make sure the entire BW is within 76~77 or 77~81
params.Slope_MHzperus = 79; % MHz/us
params.Idle_Time_us = 5; % us
params.Tx_Start_Time_us = 0; % us
params.Adc_Start_Time_us = 6; % us
params.Ramp_End_Time_us = 40; % us
params.Sampling_Rate_ksps = 8000; % ksps
params.Samples_per_Chirp = 256; % Number of samples per chirp
params.Rx_Gain_dB = 30; % dB
% Frame config
params.nchirp_loops = nchirp_loops; % Number of chirps per frame
params.Num_Frames = Num_Frames; % number of frames to collect data
params.Dutycycle = 0.5; % (ON duration)/(ON+OFF duration)
params.Chirp_Duration_us = (params.Ramp_End_Time_us+params.Idle_Time_us); % us
params.NumberOfSamplesPerChannel = params.Samples_per_Chirp * nchirp_loops * params.NumAnglesToSweep *params.Num_Frames; %number of ADC samples received per channel. this value is used in HSDC for data capture


%d = 0.5*actual wavelength/wavelength for antenna design = 0.5 * actual center frequency/board antenna design frequency
centerFrequency = params.Start_Freq_GHz+(params.Samples_per_Chirp/params.Sampling_Rate_ksps*params.Slope_MHzperus)/2;
d = 0.5*centerFrequency/TI_Cascade_Antenna_DesignFreq;
params.d_BF = d;


%advanced frame config
params.Chirp_Frame_BF = 0; % 1 - chirp based beam steering, 0 - frame based beam steering
params.numSubFrames = 1;
%paramters for subframe 1
if params.Chirp_Frame_BF == 0 % frame based
params.SF1ChirpStartIdx = 0; %SF1 Start index of the first chirp in this sub frame
params.SF1NumChirps = 1; % SF1 Number Of unique Chirps per burst
params.SF1NumLoops = nchirp_loops;% SF1 Number Of times to loop through the unique chirps in each burst
%multiply 200 to convert the value to be programed to the register %example:2000000=10ms
params.SF1BurstPeriodicity = (params.Ramp_End_Time_us +params.Idle_Time_us)...
*nchirp_loops /params.Dutycycle*200; %example:2000000=10ms
params.SF1ChirpStartIdxOffset = 1; % SF1 Chirps Start Idex Offset
params.SF1NumBurst = params.NumAnglesToSweep; % SF1 Number Of Bursts constituting this sub frame
params.SF1NumBurstLoops = 1; % SF1 Number Of Burst Loops
params.SF1SubFramePeriodicity = params.SF1BurstPeriodicity*params.NumAnglesToSweep;%SF1 SubFrame Periodicity
elseif params.Chirp_Frame_BF == 1 % chirp based
params.SF1ChirpStartIdx = 0;
params.SF1NumChirps = params.NumAnglesToSweep;
params.SF1NumLoops = nchirp_loops;
%multiply 200 to convert the value to be programed to the register %example:2000000=10ms
params.SF1BurstPeriodicity = (params.Ramp_End_Time_us +params.Idle_Time_us)...
*nchirp_loops /params.Dutycycle*200 * params.NumAnglesToSweep ;
params.SF1ChirpStartIdxOffset = 1;
params.SF1NumBurst = 1;
params.SF1NumBurstLoops = 1;
params.SF1SubFramePeriodicity = params.SF1BurstPeriodicity;

end

%frame repitition time in unit of ms. THis based on params.SF1SubFramePeriodicity
params.Frame_Repetition_Period_ms = params.SF1SubFramePeriodicity/200/1000;


%% algorithm parameters
params.ApplyRangeDopplerWind = 1;
params.rangeFFTSize = 2^ceil(log2(params.Samples_per_Chirp));

%% derived parameters
chirpRampTime = params.Samples_per_Chirp/(params.Sampling_Rate_ksps/1e3);
chirpBandwidth = params.Slope_MHzperus(1) * chirpRampTime; % Hz
rangeResolution = speedOfLight/2/(chirpBandwidth*1e6);
params.rangeBinSize = rangeResolution*params.Samples_per_Chirp/params.rangeFFTSize;

end

Regards,

Katherine

HI,

             You can find the guide at

C:\ti\mmwave_studio_03_00_00_14\docs\mmwave_studio_cascade_user_guide

Also, in the script can you try with 

nchirp_loops = 16;
Num_Frames = 16;

Regards