Frequency Allocation Scheme for Interference Avoidance in Cellular System with Fixed Relay

The introduction of fixed relays is expected to be inevitable as 4G wireless communications coverage is expanded and data processing ratios enhanced, and for reducing costs of base station extension and backhaul communication network holding. Additional interference is an unwanted concomitant of adding many fixed relays to the existing cellular system without an efficient frequency allocation scheme. We propose an efficient frequency allocation scheme for avoiding co-channel interference between cells/sectors when installing fixed relays on cellular systems. The proposed frequency allocation scheme can minimize the co-channel interference between cells/sectors by not sharing a frequency band among neighboring fixed relays, or between the base station and fixed relays, and instead using different frequency bands in sectors.