Nutaq has providing various products for research and development for physical layers for various radio technology. Recently they combined one of their hardware product (picoSDR) with Amarisoft LTE protocol stack to support full LTE network in a small box. Refer to Nutaq picoSDR page for the details.
The small box shown below has both SDR hardware and embedded PC running SDR baseband software and core network software. Nutaq promotes it as 'LTE in a box'.