Experimental Assessment of Harmful Interference Between Broadcasting and Distributed Cognitive Radio Networks in Real Scenarios

Spectrum scarcity has become a challenge for the growing demand of wireless services. Paradoxically, although most of the sub-1-GHz spectrum is assigned it is underutilized in the space and time domain. Several surveys demonstrate a spectrum usage efficiency lower than 20%. Cognitive Radio technologies has been proposed as a long-term solution for tackling spectrum scarcity and inefficiency. However, a major concern has been the interference to and from the primary licensed service. In this paper we investigate the coexistence between broadcasting digital television and LTE-A distributed cognitive radio in real scenarios. Our research revealed that, for the worst case the LTE-A distributed cognitive radio causes a degradation of the broadcasting service QoE higher than 60%. For the LTE-A network there is up to 5 dB C/I margin that does not worsen its QoS, being a potential resource for networking optimization and interference mitigation.