Design of coordinated multi-point (CoMP) transmission and reception schemes for the fourth generation cellular downlink

In this paper we consider the design of coordinated multi-point transmission and reception schemes for the fourth generation cellular downlink, wherein a set of disparate transmission points serve multiple users on an available spectrum. For efficient resource allocation the set of transmission points is partitioned into several clusters and each cluster is pre-assigned a separate set of users that it should serve. Our focus in this paper is on joint resource allocation (joint scheduling) using all the transmission points in a cluster. We adopt a two-step approach for this joint resource allocation problem. The first step determines a feasible user selection using a suitable approximation algorithm after making certain simplifying assumptions on the transmit precoders that can be employed. In the second step, which is also our main contribution, the transmit precoders are fine tuned for a given user selection and per-antenna transmit power constraints are enforced.