I am perceiving an behavior that, at least for me, is a little bit odd. Sometimes, not always, the signals of the I and Q get inverted. I mean I build my wave format, like this:
and after I receive it, the half sinusoids that were supposed to be, for example, positive shows up negative and vice versa, maybe showing the RX is easier. What I receive is something like this:
These are the raw values of I and Q I am receiving.... no treatment nothing, and if you flip these, they are much closer to the original data sent! Well OK, compare the flipped version below with the first graph!
I mean I don't know if this is an expected behavior (I hope not) or if it is something that I messed up with my configuration.. or there is an option somewhere... I don't know. The thing is that it does not do that always, sometimes it goes as I am expecting and I manage to decode!
Main configuration (FMCOMMS4):
- Ensm mode: FDD
- Frequency: 2.4GHz
- Gain: Manual : 30 db
- Sampling frequency: 2MHz
- TX attenuation: 0
- Calibration mode: auto
This happens in all three configurations I have tested:
a. loopback cable between RX and TX
b. over the air loopback between the same board RX and TX
c. From board A to board B over the air
Any ideas are welcome!!!