Dynamic channel assignment with flexible reuse partitioning in cellular systems

Abstract

In cellular communications, how to achieve optimum system capacity with limited frequency spectrum is one of the main research issues. Many dynamic channel assignment (DCA) schemes have been proposed and studied to increase the capacity of cellular systems. Reuse partitioning (RP) is another technique to achieve higher capacity by reducing the overall reuse distance. In convention, when RP is exploited in DCA, a portion of channels are assigned permanently to each partitioned region (A. Pattavina et al., 1999 and Steve I. Chen et al., Sept. 2003). However, the number of channels assigned to each region may not be optimum due to the uneven and time-varying traffic. In this paper, a new network-based DCA scheme with the flexible use of RP technique is proposed, namely flexible dynamic reuse partitioning with interference information (FDRP-WI). In this scheme, channels are open to all incoming calls and no channel allocation for each region is required. As long as the assignment satisfies the co-channel interference constraints, any user from different regions can use any channel. The scheme aims to minimize the effect of assigned channels on the availability of channels for use in the interfering cells and to reduce their overall reuse distances. Simulation results have confirmed the effectiveness of FDRP-WI scheme. Under both uniform and nonuniform traffic distributions, FDRP-WI exhibits outstanding performance in improving the system capacity. It can provide over 100% capacity improvement as compared to conventional fixed channel assignment scheme with 70 system channels at 1% blocking probability.