Intra-operator spectrum sharing concepts for energy efficiency and throughput enhancement

Cognitive radio and other dynamic spectrum sharing paradigms have enjoyed the limelight recently for their potential to realize a number of benefits for communications systems. The majority of investigated solutions thus far have looked at primary/secondary access and sharing of spectrum among different spectrum owners. In contrast, this paper investigates solutions for spectrum sharing among different bands owned by the same entity, such as a mobile operator, and demonstrates considerable potential for such solutions to improve power efficiency for the network and to increase throughput. The paper utilizes four means to achieve this potential: spectrum sharing through the opportunistic movement of users between bands allowing radio network equipment in other bands to be switched off when possible, spectrum sharing to opportunistically improve links´ propagation characteristics therefore reducing necessary transmission power, better interference management in spectrum sharing to reduce necessary transmission power, and the opportunistic aggregation of spectrum bands to increase achievable throughput. Power consumption reductions of over 50%, both in terms of mains power draw and in terms of necessary transmission power, are demonstrated. Moreover, throughput enhancements of up to 20% are achieved.