The Impact of Combined Physical Layer Cooperation and Scheduling for the Downlink of LTE-Advanced Networks

In this paper, five different locally restricted cooperation schemes for the downlink of 4G systems are compared. Interference among different sectors is mitigated and the downlink capacity is increased. The focus of our research is to investigate the potential of combined physical layer cooperation and scheduling by considering user-outage within the coordinated multipoint (CoMP) schemes to accomplish further power reduction of the eNodeBs, while maintaining a target data rate. Two methods to identify and discard users requiring large powers are proposed. One is based on a simple peak power constraint, whereas the second approach assumes a channel-aware scheduler which is able to defer data packets. Both outage criteria are implemented for all cooperation schemes and compared with each other. The power reduction achieved is determined by means of the CDF of the peak powers per sector for all considered cooperation schemes.