IWR1443: Question of angle measurement in swra549

Zhaoyu

Intellectual 285 points

Part Number: IWR1443

Hello,

In page 7 of swra549, it mentioned that the angle resolution is 17 degree.

But in figure 9, it seems like to have a better angle resolution.

Could you please tell me how figure 9 is made?

Zhaoyu

over 7 years ago

0 Akash Gondalia over 7 years ago

TI__Guru 50240 points

Hello Zhaoyu,

The Angular Resolution of 17 degrees corresponds to using a multiplexing MIMO Chirp Configuration technique. Without this technique the Angular Resolution is 36 degrees. Does this make sense?

If you're interested in learning more about MIMO Radar then I'd recommend looking at this App Note: www.ti.com/.../swra554.pdf

Cheers,
Akash

0 Zhaoyu over 7 years ago in reply to Akash Gondalia

Intellectual 285 points

Hello Akash,

I am aware of that the angular resolution is 36 degree.

My point is that, in figure 9, the unit of each grid is very small, seems like 5 degree.

I want to know, why the unit of grid is 5 degree, how the figure is made?

BR,

Zhaoyu.

0 Akash Gondalia over 7 years ago in reply to Zhaoyu

TI__Guru 50240 points

Hello Zhaoyu,

The plot is a "Heatmap" representation of the scene and based on the SNR of the return signal. You'll notice that while the unit of the non-MIMO grid is about 5 degrees, the unit of the MIMO grids are less than 3 degrees.

Does this answer your question? If it doesn't, would you clarify what you mean about how the figure is made? I can get in contact with the team that authored this paper.

Cheers,
Akash

0 Zhaoyu over 7 years ago in reply to Akash Gondalia

Intellectual 285 points

Hello Akash,

Thanks a lot for your quick respond.

My question of 'how the figure is made' means that, if the angluar resolution is 17 degree with MIMO, why unit in the figure of MIMO is about 3 degrees.

I think the unit should be same as angular resolution. Because unit of the figure is 3 degrees, it means that SNR of signal can be distinguished by 3 degrees.

Additionally, could you provide the code script of the figure?

BR,

Zhaoyu

0 Akash Gondalia over 7 years ago in reply to Zhaoyu

TI__Guru 50240 points

Hello Zhaoyu,

I've sent an inquiry to the authors of this App Note and I will let you know when they respond. This may take a few days but I will let you know as soon as I receive an answer.

Cheers,
Akash

0 Zhaoyu over 7 years ago in reply to Akash Gondalia

Intellectual 285 points

Hello Akash,
Thanks for your help.
I am looking forward to your answers.
BR,
Zhaoyu

0 Akash Gondalia over 7 years ago in reply to Zhaoyu

TI__Guru 50240 points

Zhaoyu,

Apologies for the delay, I am still in the process of getting an answer for you.

Akash

0 Akash Gondalia over 7 years ago in reply to Zhaoyu

TI__Guru 50240 points

Hello again Zhaoyu,

So with the heatmap figure we are confusing "accuracy" (the 5 degrees) with "resolution" (the 17 degrees). Resolution simply refers to the angle at which the sensor can distinguish two objects. The actual angle that the sensor will show the object is at will in fact be much finer than 17 degrees.

Cheers,
Akash

0 Zhaoyu over 7 years ago in reply to Akash Gondalia

Intellectual 285 points

Hello Akash,

Thanks for your explanation.

I can understand that "the actual angle is finer than 17 degrees".

I considered that the angle is calculate by sin-1(wλ/2πd) mentioned in SWRA554, because by this equation, we can get higher "accuracy" than "resolution".

My understanding is that, the above equation in swra554 can get high "accuracy", but cannot distinguish two object at same range with same velocity.

Is my understanding correct?

BR,

Zhaoyu

0 Akash Gondalia over 7 years ago in reply to Zhaoyu

TI__Guru 50240 points

Hi Zhaoyu,

This is correct.

Akash

0 Zhaoyu over 7 years ago in reply to Akash Gondalia

Intellectual 285 points

Hello Akash,

Thanks a lot for your confirmation.

Zhaoyu

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IWR1443: Question of angle measurement in swra549