Capacity Analysis of Interlaced Clustering in a Distributed T ransmission System With Without CSI T
Abstract: With growing base-station density and decreasing frequency reuse factor, intercell interference and low cell-edge user rates are becoming serious problems. Legacy solutions like fractional frequency reuse are simple to implement but are suboptimal. In this paper, we investigate interlaced clustering as a solution to the edge user problem for a general distributed cellular transmission system. In interlaced clustering, several different coverage patterns coexist on disjoint parts of the spectrum. We demonstrate how various previously suggested network architectures can be interpreted as special cases of interlaced clustering. We then characterize the downlink user throughputs at the proportional fairness operating point of the rate region for both of the cases that the transmitter does, or does not, have channel state information. Based on this derivation, we develop a novel algorithm to solve the resource allocation problem for systems with interlaced clustering. Simulations based on practical cell parameters show that interlaced clustering can provide, on an average, a 100% gain on edge user rate without appreciable loss in rates elsewhere. We also verify that this result is robust to irregular deployment of the remote antenna units.