Improvement of coverage probability by subband scheme in CDMA macro-micro cellular system

When fast-moving users pass through micro-cellular systems, some problems arise, such as a large amount of handoff trials and instability of handoff control. To overcome these problems, macro-micro cellular systems have been proposed recently. The interference, however, between both cell classes in the macro-micro cellular system is a critical problem, particularly in CDMA systems. This report describes the performance of a CDMA subband system in which the CDMA frequency band is divided into several subbands and both cell classes use the subbands simultaneously. Through evaluations of the uplink simulation, it is found that the characteristics of coverage probability are improved at both the macrocell and microcell by the CDMA frequency band division.