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IWR6843: calculation about DOA_OUTPUT_MAXPOINTS

Shine
Genius 13655 points
Part Number: IWR6843

Hello Champs,

IWR6843ISK ES2.0

In the section 4.5.2.1 of 3D_people_counting_demo_implementation_guide.pdf, it mentions that the maximum of DOA_OUTPUT_MAXPOINTS is 750. 

In the 3D_people_count_68xx_dss project, the definition of DOA_OUTPUT_MAXPOINTS is DOA_OUTPUT_MAXPOINTS=MAX_DYNAMIC_CFAR_PNTS*4+MAX_STATIC_CFAR_PNTS.

1. MAX_DYNAMIC_CFAR_PNTS is the doppler CFAR detection points, 4 refers the number of RX antenna, MAX_STATIC_CFAR_PNTS refers to distance CFAR detection points, is it correct?

If yes, when enabling 3TX 4RX, the IWR6843ISK has 8 virtual antennas in Azimuth and 2 virtual antennas in Elevation.  Why the multiplier is "4"?

Besides, why it adds MAX_STATIC_CFAR_PNTS instead of multiplying MAX_STATIC_CFAR_PNTS in the equation. 

2. What is the maximum point clouds supported for single frame on IWR6843ISK?



Thanks

Regards,
Shine

  • +1
    TI__Mastermind 37805 points

    Hi Shine,

    I believe that factor of 4 is there to encourage more dynamic points than static points because they're often more relevant to the user. The maximum number of points is 750 for this application based off the code you've provided. I am confident that you could increase or decrease this limit depending on the amount of processing you do on-device. It is likely a timing challenge, where if there are too many points, the UART will become overwhelmed or the processor may not have enough time to complete its operations before the next frame begins, so as the code becomes more custom, the limits will have to be tested.

    Best,

    Nate