On simultaneous sensing and reception for cognitive LTE-A systems

We consider the application of cognitive radio technology in future LTE-A systems. The carrier aggregation (CA) features of LTE-A can be exploited for enabling a cognitive operation in a subset of component carriers. Spectrum sharing between different network operators, device-to-device communications and the use of unlicensed bands for LTE-A are potential applications for such an operation. Sensing is expected to play an important role in such systems. To this end we explore the possibilities of spectrum sensing, especially the sensing while receiving a desired signal, in LTE-A systems. Specifically, an energy detector based on reference signal cancellation is introduced and compared to a beamforming based energy detector under practical channel conditions and realistic channel estimation assumptions. The results are expected to play an important role in the development of protocols for cognitive operation in LTE-A systems.