Antijam WLAN link for using ISM or uni bands

If I wanted to use the ISM or unni bands (like 900 MHz, 2.4 GHz, 5-6 GHz) to send 3 mbps in the presence of very strong interferring signals, how would I go about it. FHSS, DSSS, some other more exotic approach? And are there any wlan cards out there that are off-the-shelf with this best antijam technology.