IWR6843AOP: Clutter Removal in ITB 4.11

Tony Simple

Part Number: IWR6843AOP

Dear TI experts,

I got really confused when reading the clutter removal code in RADARDEMO_aoaEst2DCaponBF_staticRemoval.c (ITB 4.11) and will be really appreciated if you guys can help me in answering these questions:

The overall idea is to calculate 4 antennas in one loop as shown in line 114, is it right? That is confirmed between lines 123~141. But why does input2 use antIdx + nRxAnt * (nChirps >>2) rather than antIdx + 1?
Why is a half of chirps used to accumulate one antenna’s signal in line 124?

Thanks

over 2 years ago

0 Alec May over 2 years ago

TI__Genius 17265 points

Hi,

Can you provide information regarding which demo from the mmWave Industrial Toolbox you are using specifically?

Best Regards,
Alec

0 Tony Simple over 2 years ago in reply to Alec May

Intellectual 390 points

Hi, Alec:

Sorry for not mentioning the demo is the People Counting Overhead

Best Regards,
Tony

0 Nathan Block over 2 years ago in reply to Tony Simple

TI__Mastermind 37805 points

Hi Tony,

This is going to take some time to look into. Give me a day to investigate, and ping this again if you don't get a response by tomorrow.

Best,

Nate

+1 Muhammet Yanik over 2 years ago

TI__Intellectual 790 points

Hello.

The main idea behind this code is to use the C674x DSP intrinsics as efficient as possible. Hence, in this code, every consecutive 2 RX samples (each is complex16 = 4 bytes) are aligned into 8 bytes, and summed parallel in the DSP core.

As I depicted in the following figure, the code gets pairs of RX samples (input1-input2, input3-input4), aligned them into 8bytes (to handle 2 RX consecutive samples in parallel), then loops though the chirps. Since, the pairs are selected in two halves of the available chirps, it needs to loop through the half of the total number of chirps.