Challenges in open spectrum systems

Authorised Shared Access/Licensed Shared Access (ASA/LSA) are a key enabler for an efficient use of the available spectrum in 5G and beyond networks, which will become absolutely compulsory in order to cope with the unprecedented wireless traffic growth that has been predicted for the 2014–2020 period. ASA/LSA policies represent an intermediate solution between the traditional “licensed” and “unlicensed” schemes in which an incumbent user of a certain frequency band shares it with a concrete set of ASA/LSA licensed users under a determined set of time and coverage restrictions. In other words, they are based on the open spectrum concept, where for given periods of time and in a given bandwidth, the owner of a radio spectrum band opens it for secondary users. Overlapped zones between secondary operators entail severe problems. This talk will present spatial signal processing techniques for proper interference management towards an efficient implementation of ASA/LSA schemes guaranteeing the desired QoS to all sharing users. Two differentiated scenarios with critical importance inside future networks will be considered: short-range communications and satellite communications and its possible extensions to optical wireless communications.