Capacity improvement with uplink/downlink power control in CDMA cellular systems

Combining macrocell and microcell by a two-tier overlaying and underlaying structure for code-division multiple access (CDMA) systems is becoming a popular trend in the near future. However, the cochannel interference between microcell and macrocell in a two-tier structure is different from that in the homogeneous structure. This paper investigates the schemes to enhance the capacity of system. The power control schemes for both the uplink and downlink are also considered. We obtain performance measures, such as the blocking probability, C/I, capacity and service hole area, by means of computer simulation. The results show that the capacity of the macrocell and microcell can be significantly increased if appropriate power control schemes are adopted.