Neighbor-friendly user scheduling algorithm for interference management in LTE-A networks

Downlink inter-cell interference is considered as a major challenge for cellular systems. For this purpose, the Long Term Evolution Advanced (LTE-A) standard uses soft frequency reuse (SFR), which assigns two fixed disjoint portions of the available bandwidth, one for center users and one for cell edge users. However, SFR forces the allocation of users in a certain portion of the bandwidth regardless of the users´ channel conditions. Neighbor-friendly power control techniques have been studied as a means to reduce inter-cell interference in neighboring cells without forcing users to a certain bandwidth portion. Nevertheless, they are not directly applicable to LTE-A since the granularity of the power levels and the exchange of information between base stations are limited. In this paper, we use the principles of neighbor-friendly power control to develop a user scheduling algorithm that assigns physical resource blocks (PRBs) to users based on the channel quality indicator (CQI) and uses relative narrowband transmit power (RNTP) signalling to reallocate users whenever inter-cell interference is detected. Compared to the baseline algorithms, the proposed algorithm is able to increase the instantaneous CQI efficiency especially of cell edge users.