IQ DATA - Regarding

[SRINATH]

Hi Team,

I am trying to find the angle of arrival using IQ datas in the AOA algorithm in BLE.

I have kept TI cc2642r as transmitter (rtls_responder) and receiver as nordic (nrf52833 dk). I get some iq samples when printing iq. But how can I verify if iq is correct.

I Am getting iq only in a range of (-15 to 15).

[Simonr]

Hi

You will not be able to review/verify the raw IQ data. The way to go here would be to sample data and convert it to amplitudes/angles, then evaluate the stability of the angle and data. Our solution only provides the raw data, and the customer/user is expected to find a way to translate the data into vector form to use it as direction finding data. You can check out this page for information on how to do so.

Best regards,

Simon

[SRINATH]

Hi Simonr,

Thanks for replying, Default antenna pattern given by nordic is 12 which is configured in nrf52833.overlay file (direction_finding_connectionless_rx) code. I am using 16 patch antenna array from coreHW (CHW1010-ANT2-1.0).

I have changed the antenna pattern to 16 in main with reference to data sheet of antenna array.



And, I have also changed the nrf52833.overlay file, as the image given below.

But I am not receiving any IQ samples. what other changes should I make to get IQ datas.

[Simonr]

Is the antenna array set up to do switching on itself or have you connected the GPIOs P0.03, P0.04, P0.28 and P0.29 to drive antenna switching? If it's connected to the GPIOs to control switching I think these changes should be sufficient. What output are you seeing from the receiver instead of IQ samples on your end? Could you upload a log file so we can take a look?

Best regards,

Simon

[SRINATH]

Hi,

Change  CONFIG_BT_CTLR_DF_MAX_ANT_SW_PATTERN_LEN as 16 in autoconf.h

 #define CONFIG_BT_CTLR_DF_MAX_ANT_SW_PATTERN_LEN 16 

I have tried this, it is working fine for me.