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BOOSTXL-AOA: AOA obtained from RTLS monitor is along which axis

Akansha Verma
Expert 1220 points
Part Number: BOOSTXL-AOA


Hi,

I want to apply the Triangulation algorithm over the AOA  data obtained for that i need to know the axis along which AOA obtained is measured.

I have attached a snippet of my setup.

Please confirm that the angle i mentioned is AOA i.e, angle from slave to passive

Thanks

Akansha

  • 0
    TI__Genius 11810 points

    Hi Akansha, 

    Angle is relative to the AoA board, not the slave. Fore more details see:  http://dev.ti.com/tirex/explore/node?node=AHYhhuDNTaRXzkOlahOlvA__pTTHBmu__LATEST 

    -Simon

  • 0 in reply to Simon J
    Expert 1220 points

    Hi,

    I have some queries regarding angle calculation:

    1. What is the axis in Array of Antenna which we need to considered to calculate the angle of incident packet?

    2.  Angle obtained on RTLS monitor is positive as well as negative sometimes, on what basis the polarity of angle depends?

    3. When my Array 2 is close/facing to Slave then i am getting negative AOA- What does this imply?

    Please if possible plot the axis in BOOSTXL-AOA, so that i can write the algorithm to localize the slave using AOA.

    Thanks

    Akansha

  • 0 in reply to Akansha Verma
    TI__Guru 56275 points

    Hi,

    For more information regarding AoA, you can take a look at the SimpleLink Academy training. For step 3(here) from the introduction, you can see how to interpret the angle.

    In our out of box example, we set the junction of array 1 and array 2 as 0 degree. Then when the slave goes to array 1, it's positive and vice versa. 

    This is just an example, you can define your own reference point.

  • 0 in reply to Christin Lee
    Expert 1220 points

    Hi,

    How you are setting this:when the slave goes to array 1, it's positive and vice versa. 

    Thanks

    Akansha

  • 0 in reply to Akansha Verma
    TI__Guru 56275 points

    Hi,

    When we calculated the relative phase different, we do angle compensation by applying the following parameters into the following equation

      // Write back result for antenna pairs
  for (uint8_t pair = 0; pair < numPairs; ++pair)
  {
    const AoA_AntennaPair *p = &gAoaReport.antConfig->pairs[pair];
    gAoaReport.antResult->pairAngle[pair] = (int)((p->sign * antenna_versus_avg[p->a][p->b] + p->offset) * p->gain);
  }

    As you can see that the .sign field for antenna array 1 is positive(1) and for antenna array 2 is negative (-1). That's how we decide the angle.

    For more information regarding angle compensation, please take a look at our software user's guide.

    For more information regarding how the theory works, please take a look at our SimpleLink Academy.