I'm working on a project where OFDM subcarrier spacing can go down to 750 Hz. (I know AD9361 is OK with LTE where subcarrier spacing is 15 kHz.)
What I observe is, the symbols close to DC get impaired when the subcarrier spacing is less than 15 kHz. It is also observable when I receive some tones with very low frequencies close to DC. Received tone gets attenuated in addition to some frequency offset.
Is it possible to tune some parameters on AD9361 (not sure which parameters those should be , DC offset removal related ones?) to improve the quality on the symbols which are around DC?
If you can help with this or confirm it's not possible that would be really helpful.