RE: How to get I and Q data from the antenna array for direction finding purpose?

Rishitha — Mon, 13 Mar 2023 04:40:59 GMT

Hello Swathy,

Thankyou so much for the reply.

RE: How to get I and Q data from the antenna array for direction finding purpose?

SwRa — Fri, 10 Mar 2023 09:43:24 GMT

Hi Rishitha,

You will need to make necessar changes in cte_recv_cb() in main.c to print the I and Q samples.

You can take a look at this ticket: RE: AOA: Antenna switch pattern and IQ sampling via nrf52833

You always have to convert the IQ data into a vector, and then examine this to get a useful positioning data. Some formulas for calculating with IQ signals translating between polar and rectangular forms can be found here: https://www.pe0sat.vgnet.nl/sdr/iq-data-explained/

Peak Amplitude A = (I²+Q²)½

Phase Angle ϕ = tan⁻¹(Q/I)

I = A⋅cos(ϕ)

Q = A⋅sin(ϕ)

Converting IQ Data to a plain signal: I is the original signal.

Euler form: A⋅eiϕ = A⋅(cos(ϕ) + i⋅sin(ϕ)) = I + Qi

Regards,
-Swathy