I've simulated a circuit and a little confused... If I have an BPSK
RF signal at 1KHz, and I mix it with an LO of .9KHz, then I should get
100Hz still in BPSK format? PSpice says otherwise. If I filter the IF
for lowpass at 100Hz, it doesnt look like anything I could possible
work with and doesnt sync to anything. If I pass everything below
200Hz, it looks more like a sign wave, that's syncronous with the
modulation.

On the other end of the spectrum (no pun intended), if I went with
direct down converstion, what I get at the output of the mixer is a
sign that it twice the RF freq that' shifts 'dc offset'. Should I be
filtering for the DC offset?
Does anyone have a link to actual waveforms that I should see in a
typical IQ demodulation scheme? Or at least some good docs for
understanding the waveforms and what I should be looking for?