PN offset planning for synchronous CDMA based fiber-optic microcellular systems

PN offset planning methods for a multi-layer synchronous CDMA network composed of macrocells and fiber-optic microcells (fomicells) are developed. In these methods, planning of macrocells and that of fomicells are independently performed. For macrocells, an existing method, which is called the cluster reuse-based method, is used. For fomicells, it is observed that precompensation of optical delay is required at each base transceiver system (BTS) supporting fomicells. Two methods for fomicell planning are proposed. One is the cluster reuse-based method and the other is the graph coloring technique. Design examples indicate that the latter is more appropriate to the fomicell environment and yields more efficient PN-offset planning than the former.