@conference {306, title = {Experimental Testbed for 5G Cognitive Radio Access in 4G LTE Cellular Systems}, booktitle = {Proceedings of the IEEE Sensor Array and Multichannel Signal Processing Workshop (SAM{\textquoteright}14)}, year = {2014}, month = {06/2014}, address = {A Coruna, Spain}, author = {Martin Danneberg and Rohit Datta and Andreas Festag and Gerhard Fettweis} }