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AWR1843: Is there a possibility of BPM transmission for 3Txs

Rohit R
Prodigy 30 points
Part Number: AWR1843
Other Parts Discussed in Thread: AWR1642

Hi, 

I am using AWR1843 (mmWave Studio 2.0.0.2 and sdk_02_01_00_04), with which I have a couple of questions to be asked.

1. Is there a possibility for simultaneous transmission of 3 Txs (in BPM mode) and how can it be done?

2. Making use of 3 Txs, can I make use of a configuration as follows: 

     BPM mode for Tx1 and Tx2, in order to obtain Azimutal information. i.e., Tx1 and Tx2 with 0 phase, then Tx1 and Tx2 with 180 phase and later make use of Tx3 alone for elevation purpose. 

Regards, 

Rohit

  • 0
    TI__Guru 69460 points

    Hello Rohit,

    1. Yes. You can use all three Tx at a time. You need to select all the tx for select chirp in rlSetChirpConfig API and set the required BPM.

    2. Requested feature set is possible to configure AWR1843 device where each chirp index you need to set with the selected Tx phase. You can refer MRR ver2.0 which has feature of beam forming where it uses similar features.

    Regards,

    Jitendra

  • 0 in reply to Jitendra Gupta
    Prodigy 30 points

    Hello Jitendra,

    Thanks a lot for the inputs. Well, I have tried the 3Txs in BPM mode (for each chirp having 64 samples) and was able to collect the data with the help of DCA1000. But, I wanted to confirm the way that it is done. I have set the BPM config tab in such way that I transmit T1+T2+T3 in 1st chirp, then T1-T2+T3 in 2nd chirp and T1+T2-T3 in 3rd chirp.

    For 1st chirp transmission, I SET the start & end chirp to 0 in sensor config tab and jumped to bpm config tab. I had start and end index as 0(by default) and set the TX Off and TX On for ALL the Txs to be 0. Then, clicked on SET and ACTIVATE.

    For 2nd chirp transmission, I SET the start and end chirp to 1 in sensor config tab, and came to the bpm config tab. I have the following picture attached. I found the Start and End index to be changed by itself to 511. I made changes only with the TX Off, TX ON for ALL Txs as follows. Then, clicked SET and ACTIVATE.

    For 3rd chirp transmission, I SET the start and end chirp to 2 in sensor config tab, and came to the bpm config tab. I have the following picture attached. I found the Start and End index to be same as previous by itself. I made changes only with the TX Off, TX ON for ALL Txs as follows. Then, clicked SET and ACTIVATE.

    Doing the further steps in Sensor config, I was able to collect the data. My questions are:

    1. What's the importance of Start and End Index in BPM config tab, how do I make use of it?

    2. Is the phase part done correctly as per the configuration that I wanted i.e., wrt to TX Off and TX ON?

    3. After I click ACTIVATE, I find the tool to be in "Not Responding" state for sometime. Does it happen that way or have I missed anything to change?

    4. How can I confirm that the hardware is transmitting in BPM?

    Regards,


    Rohit

  • 0 in reply to Rohit R
    TI__Mastermind 31680 points

    Hi Rohit,

    Thanks for your patience.

    1 & 2. The start index and the end index have the same meaning as in the "SensorConfig" tab. You can configure different BPM values for each of the chirps or a set of chirps using the "start" and "end" index entry. For this, you have to manually set that value according to your configuration. The default values are just a limit for your programmed configuration. 

    3. You can press “Set” for sending one set of chirp start index and end index along with its info present in the GUI. Then you can do “Activate” for sending all the configured sets of chirp start index and end index along with its info at one shot. It takes a little while to send this configuration to the device.

    4. You can confirm that from the post proccesing plots of the mmWave studio. The "Phase Stability across chirps" plot shows you the correlation for each chirp, and to verify, you can use one Tx per chirp

    Regards,

    Ishita

  • 0 in reply to Ishita Kochar
    Prodigy 30 points

    Hello Ishita,

    I appreciate your inputs, they were very informative. Just had one more thing to get it clarified regarding the BPM Compensation (decoding part).

    Currently, I am making use of the ADC data for my algorithm. So, do I have to make use of BPM compensation in my Pre-processing algo or is the BPM compensation already done in the H/w or mmWave tool. Because, by observing the data I find that they have already been compensated in the H/w or tool.

    It would be helpful if you could confirm me on the same.

     Regards, 

    Rohit 

  • 0 in reply to Rohit R
    TI__Mastermind 31680 points

    Hi Rohit,

    Raw ADC is sent from device with the Phase rotation (BPM). So you should be able see each successive chirp with the programmed phase.

    Say for example, if you've programmed the BPM code to be alternate for each chirp (i.e 10101010), you will see the next chirp 180 degrees rotated and so on.

    Regards,

    Ishita

  • 0 in reply to Ishita Kochar
    Prodigy 10 points

    Hello Ishita,

    Thank you for your response.

    we were using the AWR1642 EVM in BPM mode, but I missed the following points.

    1. Our understanding was that in first chirp TxA will be “0”, TxB will be “0” and in second chirp TxA will be “0”  and TxB will be “1”.

                  So we did using bpmCfg 0 0 0 1 in the Config file.

                  We didn’t check "<subFrameIdx> <enabled> <chirp0Idx> <chirp1Idx>" in MmwDemo_CLIBpmCfg.

                  So according to the config we have disabled the BPM, so we didn’t see much change in output, now we shifted to AWR1843.

    1. In AWR1843 EVM we are having 3 Tx that are to be working together.

    Now once we started doing change to cli.c file in MSS we came across the mistake.

    So we added another field chirp2Idx "<subFrameIdx> <enabled> <chirp0Idx> <chirp1Idx> <chirp2Idx>"

                   But when we collected the BPM data we followed the pattern as described in  above conversation i.e chirp1: 000 (TxA+TxB+TxC), chirp2: 010 (TxA-TxB+TxC), chirp3: 001 (TxA+TxB-Txc).

                   

    My question is how to configure the hardware in CCS and what could be appropriate command line that can e used.

    Currently I have added bpmCfg -1 1 0 0 0   and the system is running like it was working for TDM mode.

    I am sure this is not the correct way.

    Regards

    Praveen Mogre

  • 0 in reply to praveen mogre
    TI__Guru 69460 points

    Hello Praveen,

    If you trying xWR18xx mmw demo then it doesn't support BPM feature in this application.

    You need to modify the application for BPM support. You can take reference from xWR16xx mmw demo for BPM implementation but that has BPM for two Tx only.

    Regards,

    Jitendra