The CDMA cellular system can provide more capacity than AMPS systems and the hierarchical layer of cells is required for system design. However, system performance and capacity is degraded due to the cochannel interference between microcell and macrocell if a single frequency channel is shared. This paper proposes three multi-channel access schemes where various frequency channels are assigned for microcell and macrocell. Performances of channel capacity, blocking probability and blocking ratio in uplink and downlink are evaluated. Due to channel segregation and thus the cochannel interference among macrocell and microcell are minimized, the proposed scheme 3 where all channels are accessible sequentially in macrocell and microcell performs the best in system capacity and blocking probability than the other schemes.
- Multi-channel access