• State TI Thinks Resolved
  • Locked Locked
  • Replies 17 replies
  • Answers 1 answer
  • Subscribers 29 subscribers
  • Views 3485 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

Original question:

DCA1000EVM: AWR1642EVM mmWave studio TDM or BPM MIMO setting

DCA1000EVM: IWR1443 mmWave studio TDM MIMO system for angle test

WEIHUA JIANG
Prodigy 190 points
Part Number: DCA1000EVM

Hi,

I am now trying to test the raw data about TDMA MIMO(2Tx, 4Rx) system using IWR1443. 

I use the fft method to measure the range and angle. For 4 Rx, each Tx (1Tx, 4Rx) can get the same angle result. In order to get better angle resolution, I put two <1Tx, 4Rx>data together to get 8 virtual antenna and the result has 6 degree deviation compare to （1Tx，4Rx）result. Do it means I need to add the calibration at the transmiters? How can I remove this difference

Thanks,

Weihua

  • 0
    TI__Genius 11405 points

    Hi Weihua,

    Which two TX antennas are used? Among the three TX: TX1, TX2, TX3, TX2 is elevation antenna. 

    Thanks and Regards,

    Michelle

  • 0 in reply to Michelle Liu
    Prodigy 190 points

     

    Hi Michelle,

     Yeah, I used the Tx1 and Tx3.  Actually I have tested the 3Tx+4Rx, Tx1 and Tx3 combination also has 6 degree deviation compare to(1Tx,4Rx). I just set 'Connection, StaticConfig, DataConfig,SensorConfig' page, and others is default in RadarStudio. Do you know what may cause this difference?

    Thanks,

    Weihua

  • 0 in reply to WEIHUA JIANG
    TI__Genius 11405 points
    WeiHua,

    I think it is related to the resolution change from using 1TX to 2TX. With one tx, the angle resolution is only 30 degree but 2TX gives 15 degree. Therefore, you get more accurate result.

    Thanks and Regards,
    Michelle
  • 0 in reply to Michelle Liu
    Prodigy 190 points

    Hi Michelle,

    I don't think it may cause by the resolution problem, because I try to find the most value in fft(range and angle domin) result cluster which has the 6 degree difference in 1tx-4rx and 2tx-4rx. If the resolution is different, I think it may effect the cluster size, not the most value point.

    The attached file is the result for 2tx-4rx, and 1tx-4rx(one target scenario), can you help me to check it out?

    Thanks,

    Weihua

  • 0 in reply to WEIHUA JIANG
    TI__Genius 11405 points
    Hi WeiHua,

    Your comment makes sense, but the result is strange. How did you do the post-data processing? It's customer code?

    I ran the mmwave studio with xwr14xx and tried 1t4r and 2t4r, the device location from plot (Detection & Angle Estimation Results) stays the same.

    One thing I'd like to check is how did you setup the tx1 and tx3 using the chirp index. What I suggest to do after chirp profile is set, in the chirp section, first choose Start chirp for config and End chirp for config both as 0 with TX0 selected, press "Set". Then change Start chirp for config and End chirp for config both to 1 with TX2 selected, press "Set" again. In frame config, Start chirp TX is 0 and End chirp TX is 1.

    Hope that helps.

    Thanks and Regards,
    Michelle
  • 0 in reply to Michelle Liu
    Prodigy 190 points
    Hi Michelle,

    1) I use the fft-method and music method to process the data, and test the target from different angle, but the result always has about 6 degree difference between 1tx4rx and 2tx4rx for these two methods.

    2) I set the same profile for two tx, and set the chirp config as you say. I think it may have some other problems.

    Thanks,
    Weihua
  • 0 in reply to WEIHUA JIANG
    TI__Genius 11405 points

    Weihua,

    What is the FFT size you used, is it same for both cases or does it depend on the number virtual antennas?

    Did you try using mmwave studio to process the data? Do you still get the offset? 

    Thanks and Regards,

    Michelle

  • 0 in reply to Michelle Liu
    Prodigy 190 points
    Hi Michelle,

    I used the fft size 256 and 181 for range and angle respectively, and it is same for both cases.

    I do not try the radar stdio to process the data, I will try it.

    Thanks,
    Weihua
  • 0 in reply to WEIHUA JIANG
    TI__Genius 11405 points

    Hi WeiHua,

    To check the exact location of the object, you can use the matlab tool button and find the object location.  See attached figure for example. Then you will can tell if there's differences when using different TX selection.

    Thanks and Regards,

    Michelle

  • 0 in reply to Michelle Liu
    Prodigy 190 points

    Hi Michelle,

    I know what you mean, and I have taken one more experiment. For tx1-rx4 and tx2-rx4, there are same angle results in radar studio 'Detection & Angle estimation Results' .

    But if I put these raw data in my fft process code,  for tx1-rx4, my result is same as radar studio. For tx2-rx4, it always has 6 degree offset between my code processing and radar studio post-processing----however, when i get the 2 tx signal from tx2-rx4 data and form 2 tx1-rx4 data, then test these two tx1-tx4 respectively, the results are also right. I am confused whether you have apply the calibration in post processing, and how you put these 2tx signal together---i firstly get the tx0-rx4, tx3-rx4 data, then put it as [tx0-rx4 tx3-rx4].

    Thanks,

    Weihua

  • 0 in reply to WEIHUA JIANG
    TI__Genius 11405 points
    Weihua,

    Just to let you know that we are trying to get response from mmwave studio developer. We will let you know as soon as we got a response.

    Thanks and Regards,
    Michelle
  • 0 in reply to Michelle Liu
    TI__Genius 11405 points
    Weihua,

    There is no calibration on tx side. But other than that, we don't have more information.

    Thanks and Regards,
    Michelle
  • 0 in reply to Michelle Liu
    Prodigy 190 points
    Hi Michelle,

    Can you help to see this post, it also has the same problem with us.
    e2e.ti.com/.../719635

    Thanks,
    Weihua
  • 0 in reply to WEIHUA JIANG
    TI__Genius 11405 points
    Weihua,

    I'm aware of this ticket and both Joe and I tried to obtain the source code without success so far. We will let you know when we get response back.

    Thanks and Regards,
    Michelle
  • 0 in reply to Michelle Liu
    Prodigy 190 points

    Dear Michelle,

    Ok, Thanks a lot.

    Sincerely,

    Weihua

  • 0 in reply to WEIHUA JIANG
    TI__Genius 11405 points
    Weihua,

    Sorry for the delay. It took us longer than expected to find out how mmwave studio post-processes the data. The detection by mmwave studio is per tx only. It's not a combined nor a calibrated result. So your post processing may have no issue and mmwave studio should not be used as a comparison. We suggest you could use mmw demo to check if it is consistent with your calculation.

    Thanks and Regards,
    Michelle