A User-Centric Small BSs Collaboration Mechanism in Ultra-Dense Network

Ultra-dense network (UDN) is becoming significant with the rapid growth of smart terminals and traffic demands of the mobile network. In UDN, the number of small BSs is much more than that in the legacy network to satisfy the traffic demands from dense users. It is not suitable in UDN that a user is served by only one small BS. The prior research concentrated on coordinated multipoint transmissions (CoMP) where several BSs transmit the same data to the target user. Different from the prior research, this paper focuses on the scenario that several small BSs transmit different data to the same user. Then a user-centric small BSs collaboration mechanism is proposed in UDN, which comprehensively consider the traffic demand of a user, the ability of the small BS and the channel conditions. Moreover, the intra-tier interference coordination is combined with the mechanism. It can improve the UDN performance including spectral efficiency (SE) and energy efficiency (EE) and this will be proved through simulation in future work.