AWR2243: Beamforming 模式修改Beamforming 角度矩阵出现问题

感谢您对TI产品的关注！为更加有效地解决您的问题，由于问题比较复杂，我需要询问更了解这款芯片的TI资深工程师，再为您解答，一旦得到回复会立即回复给您。

1. 请问您指的是哪个example code？
2. "anglesToSteer=[-30:2:30]"，请问您需要在器件上实现什么？您是在 2 度的steps上移动吗？设备single step为5.625度；
3. 这两种情况下发生错误的比率分别是多少？

1. 采集的是BF数据，分别运行的是Cascade_Configuration_Basic.lua，Cascade_TxBF_dataCapture (SMRR), Cascade_Capture.lua；

2. anglesToSteer=[-60:1:60]我想实现从-60°到60°角度扫描，步长为1°。关于设备的single step是5.625°，首先"anglesToSteer=[-30:2:30]"是实列代码，而且在参考设计Imaging Radar Using Cascaded mmWave Sensor Reference Design.pdf第18页有提到，‘The TX beam is steering within [–60 60] with step size of 0.5 degree’，步长是可以达到0.5°的。所以我理解您说的5.625°跟BF的扫描角度不是一个物理量？

3. 经过测试我发现，anglesToSteer*nchirp_loops<2048（都是USRR/LRR/SMRR中的参数），就不会出现上述情况。例如如果在frame based steering的模式下，如果设置每个角度的chirp数为64，那么最多可以扫描的角度应该小于32。所以我想咨询一下，这是什么原因呢？手册里似乎没有提及过。

另外，我现在正在做BF和MIMO模式的对比，请问可以分享一下参考设计Imaging Radar Using Cascaded mmWave Sensor Reference Design.pdf中图19的代码吗？

扫描的步长将决定扫描角度的数量，然后将决定 2 个对象之间可能的分辨率。默认配置是基于帧的转向（frame based steering），这取决于 TDA 可以支持表单捕捉角度（form capture perspective）的最大帧大小，此详细信息列在级联用户指南中。在您计划用于在所需扫描窗口的所需范围内获得所需分辨率的配置文件中，我建议做如下调整:

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

您好，谢谢您的解答。

您说的“TDA 可以支持表单捕捉角度（form capture perspective）的最大帧大小，此详细信息列在级联用户指南中”，具体可以在哪里找到呢？我翻阅了级联用户指南没有找到答案。

另外，我现在的配置文件就是这么设置的，如下

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