AWR1243BOOST: Ambiguity in Logic and code for Doppler compensation

Hi,

The C code provided in the mmWave SDK has been tested and works with the TI EVMs. You can trust that it is correct and use it.

Let's open this question to the forum community to share any matlab code they may have.

thank you

Cesar

Hi Cesar,

Here is the algorithm flow

for i=1: Nframe

for j=1:Txantennas

1DFFT

2DFFT

end

CFAR detection

Detection matrix 

for n=1:detection objects list

doppler compensation for TX2 i.e., X(5:8)

3DFFT

end

angle plot

end

Even i applied above logic as doppler compensation

If (dopplerCompensationIdx >=numDopplerBins/2)

{

dopplerCompensationIdx -=(int32_t) numberDopplerBins;

}

dopplerCompensationIdx =dopplerCompensationIdx /2 ;

if (dopplerCompensationIdx < 0)

{

dopplerCompensationIdx +=(int32_t) numDopplerBins;

}

expDoppComp=azimuthModCoefs[dopplerCompensationIdx];

if (dopplerIdx & 0x1)

{

expDoppComp= _cmpyri(expDoppComp, *azimuthModCoefsHalfBin);

}

/* rotate symbols *

Please correct if i am doing wrong and Can you elaborate what function or process will be done in rotate symbols

When i am doing angle fft on 8 antenna peaks i am getting error .i.e., X=[P1,P2,P3,P4,P5,P6,P7,P8] combined angle fft result showing error 

but when i perform angle fft on each individual chirp data angle estimation is correct i don't understand why this happening . 

Please give me some solution!

Hi,

Please refer to the demo code provided in the mmWave SDK.

thank you

Cesar

Hi Cesar,

I have seen the SDK code and verified the algorithm flow . Both are similar 

for i=1: Nframe

for j=1:Txantennas

1DFFT

2DFFT

end

CFAR detection

Detection matrix 

for n=1:detection objects list

doppler compensation for TX2 i.e., X(5:8)

3DFFT

end

angle plot

end

 i applied below logic as doppler compensation

If (dopplerCompensationIdx >=numDopplerBins/2)

{

dopplerCompensationIdx -=(int32_t) numberDopplerBins;

}

dopplerCompensationIdx =dopplerCompensationIdx /2 ;

if (dopplerCompensationIdx < 0)

{

dopplerCompensationIdx +=(int32_t) numDopplerBins;

}

expDoppComp=azimuthModCoefs[dopplerCompensationIdx];

if (mod((dopplerIdx/2 ),1)~=0)

{

expDoppComp= azimuthModCoefsHalfBin;

}

even processing the data as mentioned above i am not getting correct angle 

When i am doing angle fft on 8 antenna peaks i am getting error .i.e., X=[P1,P2,P3,P4,P5,P6,P7,P8] combined angle fft result showing error

and i suspect that in doppler compensation my implementation is wrong

Please tell me that in --TDM MIMO (all three TX enabled)

ar1.ChirpConfig(1, 1, 0, 0, 0, 0, 0, 1, 0, 0)
ar1.ChirpConfig(2, 2, 0, 0, 0, 0, 0, 0, 0, 1)
ar1.ChirpConfig(3, 3, 0, 0, 0, 0, 0, 0, 1, 0)

Now when I go to configure my frame to use these three chirps, this would look like the following:

ar1.FrameConfig(1, 3, 20, 128, 160, 0, 1)

for above settings in adc.bin file the chirp data will be loaded as TX1, TX3,TX2,TX1, TX3,TX2,TX1, TX3,TX2,TX1, TX3,TX2,TX1, TX3,TX2,...............

Please correct if im wrong ....

Hi,

I recommend you try first 2 TX in the azimuth. Make sure that will work before you move on to 3 Tx.

The following seems correct

--TDM MIMO (all three TX enabled)
ar1.ChirpConfig(0, 0, 0, 0, 0, 0, 0, 1, 0, 0) //TX1 enabled
ar1.ChirpConfig(1, 1, 0, 0, 0, 0, 0, 0, 0, 1) //TX3 enabled
ar1.ChirpConfig(2, 2, 0, 0, 0, 0, 0, 0, 1, 0) //TX2 enabled

Thank you

Cesar

HI Cesar ,

Thanks for replying .

As you recommend me to work first with 2 TX in the azimuth antennas.

Here is the case simulated one strong static target by using Test source in mmWave Studio 2.0.0.2 

Test source settings : (static target )

Object1                          X                       Y                              Z

Position(m)                   4                       30                              0

Velocity (m/s)               0.0                    0.0                             0.0 

Signal Level(dBFS)    -2.50

Rx Antenna Position                       X                        Z

Rx1(lambda)               0.0                       0.0

Rx2(lambda)               0.5                       0.0

Rx3(lambda)               1.0                       0.0

Rx4(lambda)               1.5                       0.0

Chirp Config:(working with AWR1243boost . Now verifying with 2Tx azimuth antennas)

--TDM MIMO (all three TX enabled)
ar1.ChirpConfig(0, 0, 0, 0, 0, 0, 0, 1, 0, 0) //TX1 enabled
ar1.ChirpConfig(1, 1, 0, 0, 0, 0, 0, 0, 0, 1) //TX3 enabled

Frame Config:

ar1.FrameConfig(0,0,1, 256, 64, 40, 0, 1)

________________________________________________________________________________________

For the above setting captured IQ raw data and processed with own post processing algorithm and passed as input for TI inbuilt matlab GUI (RadarStudio PostProcessing (4.75)).

For the above settings results should be (TDM MIMO XY Results ) in GUI 

X=-4 ,     Y=30 and Z =0

But the results are 

X=-1.141, Y=30.24 and Z=0 

similar kind of results are observed for own algorithm.

In this case, does range FFT produce expected output i.e strong energy at the expected bin [noise/clutter elsewhere, there may be some bins near 0 on either side that are stronger though, ignore them]?

Ans : The range FFT produced expected output at 156 bin where the range will be 156 *range resolution = 30.4873 m

Does doppler FFT output look good [should show only energy at 0th bin]?

Ans: Yes , The energy is at 0th bin only .

If these two are good, and if you only compute azimuth FFT of all 8 virtual azimuth antennas for this scene and not do any doppler compensation [bypass completely your doppler code], do you see the expected angle?

Ans: By passed complete doppler compensation code of mine and computed azimuth FFT of all 8 virtual azimuth antennas for this scene. But also the results are wrong.

Now tell me what to do .

Please guide me with your knowledge ........ I know you are not allowed to answer straightly regarding problem but i hope you can me that what is Correct and Wrong for guiding to some extent. 

Please find the below attachment of adc_data.bin and adc_data_LogFile.txt2021.Results.rar

Please validate with your TI GUI and tell Why TI GUI showing wrong results 

Please guide me with solution as you always do .

But please do reply as soon as possible because i was doing this for a long time and i have very short time to work on .I hope you understood .

Thanks for understanding .