I'm in no way affiliated with this thing. I'm just eagerly looking forward to adding one to my APU2.
It's similar to the Lime SDR board, but in a mini-PCIe form factor. So, it can "speak" 2g, 3g, 4g, 2.5GHz wifi, GPS, or pretty much anything 10 MHz - 3.7 GHz, 2x2 MIMO, up to 120 MSPS.
It also provides an FPGA that's fully reconfigurable, so you could just do DSP on it if you wanted. FPGA routing, anyone?
Drivers (provided by manufacturer) are open-source, including linux kernel module. I don't know for sure it's compatible, but it sounds probable.