I've previously worked with super-heterodyne receivers where the IF spectral content has been above DC.
Reading the below tutorial; direct down conversion receivers are used to mix a signal of interest down to base-band. Figure 7 shows the output of the direct conversion process where the modulated signal has its frequency content either side of DC i.e. half as negative frequencies. https://www.microwavejournal.com/articles/3226-on-the-direct-conversion-receiver-a-tutorial
A similar question was asked in the link below which explains that there will be indeed overlap and corruption because of the negative frequencies. Downconversion / Demodulation of RF signal to DC
If that is the case, how is the signal recovered and what do the resultant I and Q samples look like in terms of magnitude and frequency content?
If specifics help; if we assume an already modulated carrier 1500MHz with +/-1MHz FSK signal is mixed with a 1500MHz LO. The output (and image) will be centered around DC but half the signal bandwidth will be negative, the missing half will be on-top. Its this with which I'm confused.