Performance of a new microcell/macrocell cellular architecture with CDMA access

A novel architecture for a microcell/macrocell cellular system is proposed. Instead of a universal frequency reuse and orthogonal sharing between layers, a “carrier reuse” distance is used in the macrocell layer. In the microcell layer, carriers that are not used in the overlaying macrocells can be used. With this architecture macrocells use hard handoff and microcelles use soft handoff or hard handoff depending on the carrier use in adjacent microcells. Interference and capacity analysis are performed for this architecture, showing an increment in capacity in comparison with a different carrier assignment to macrocells and microcells. An increment of 56% per carrier per cell for macrocells and only a 7% decrement in capacity per carrier per cell for the center microcell (with a carrier reuse of 3) were obtained for a path loss exponent of 4 and a standard deviation of the shadowing losses of 8 dB