NCS AOA: IQ sample data type.

RE: NCS AOA: IQ sample data type.

swz_nordic — Tue, 12 Apr 2022 03:27:43 GMT

ok,thanks.I will try your suggession.but now i see that i can use the iq data to get phase difference,then using it to calclulate the anglr of the receiver.i think it is easier.

RE: NCS AOA: IQ sample data type.

Simonr — Mon, 11 Apr 2022 08:21:17 GMT

As I mentioned earlier, you won't get reliable data from raw IQ data, so I don't recommend using time/resources on this. You need to convert the IQ data to vector form to get useful data, and then work on any issues from there.

Best regards,

Simon

RE: NCS AOA: IQ sample data type.

Harvey Zheng — Fri, 08 Apr 2022 07:28:49 GMT

Hi，

I try to look at the raw IQ data, because I want to see the difference between the IQ data in cte_report_cb and the value in the Nordic register.

I printed the IQ data here: https://github.com/zephyrproject-rtos/zephyr/blob/zephyr-v3.0.0/subsys/bluetooth/controller/hci/hci.c#L2845

0xFFC7 is the data from register，but it becomes 0xFC in CTE receive callback. That's why I think it miss some valid bits after right shift.

RE: NCS AOA: IQ sample data type.

Simonr — Fri, 08 Apr 2022 07:09:22 GMT

Can you provide some more details on what exactly you're doing? What bits are you right shifting exactly? Are you still trying to look at the raw IQ data?

Best regards,

Simon

RE: NCS AOA: IQ sample data type.

Harvey Zheng — Thu, 07 Apr 2022 10:29:48 GMT

Hi，

I noticed that by shifting right 4 bits, the data 0xFFC7 becomes 0xFFFC. It can be interpreted as low 4 bits are useless data?

Thanks.

RE: NCS AOA: IQ sample data type.

swz_nordic — Wed, 06 Apr 2022 09:05:26 GMT

ok,thanks,could you please tell me the more information abouot LOG_HEXDUMP_INF?.

You have iq sample then use the algorithm to d=get the angle.

RE: NCS AOA: IQ sample data type.

Harvey Zheng — Wed, 06 Apr 2022 09:01:28 GMT

I use the LOG_HEXDUMP_INF macro to print the IQ sample.

RE: NCS AOA: IQ sample data type.

swz_nordic — Wed, 06 Apr 2022 08:55:24 GMT

how do you print the IQ sample？do you use the two nrf5340 boards?

my output in Rx in here.

PER_ADV_SYNC[0]: [DEVICE]: 0B:2B:C5:4A:72:01 (random), tx_power 127, RSSI -69, CTE AOA, data length 0, data:

CTE[0]: samples count 45, cte type AOA, slot durations: 2 [us], packet status CRC OK, RSSI -690

PER_ADV_SYNC[0]: [DEVICE]: 0B:2B:C5:4A:72:01 (random), tx_power 127, RSSI -65, CTE AOA, data length 0, data:

CTE[0]: samples count 45, cte type AOA, slot durations: 2 [us], packet status CRC OK, RSSI -650

beside,what terminator do you use?thanks tor your reply.

RE: NCS AOA: IQ sample data type.

Simonr — Mon, 04 Apr 2022 12:10:30 GMT

The AoA direction finding solution we provide will only output the raw IQ data by default, as we don't provide the AoA algorithm necessary to make use of the data collected by the antenna array. There is no point in looking at the raw data as it needs to be converted into vector form to review it properly. You can check out this page for information on the various formulas used to translate IQ data between polar and rectangular form.

Best regards,

Simon