An ICSGC algorithm for carrier assignment in downlink coordinated multi-point with carrier aggregation

In a network deploying carrier aggregation (CA) each cell can aggregate several carriers across multiple bands and different cell may aggregate different carriers, which make the inter-cell interference (ICI) very complicated. Proper carrier assignment must be applied in downlink coordinated multi-point (CoMP) with CA to deal with this problem. The optimum carrier assignment in downlink CoMP with CA that maximizes the performance of both the whole network and each individual user is a NP-hard problem. So we abstract the carrier assignment in downlink CoMP with CA into a graph coloring problem and propose an improved color-sensitive graph coloring (ICSGC) algorithm to find out a suboptimum solution. By comparing with a greedy algorithm, the ICSGC algorithm has shown an impressive relative gain over 40% at most in total throughput and 90% in users access rate.