Spectral and Geographical Domain Coordination for IMT-Advanced Compatibility with Point-to-Point Fixed Service

Frequency intersystem interference is a phenomenon caused by coexistence of multiple wireless systems in same or adjacent areas. Consequently, frequency sharing studies play a very important rule in order to use limited spectrum resources efficiently. Because an International Mobile Telecommunication-Advanced (IMT-Advanced) systems are going to use 3500 MHz according to World Radiocommunication Conferences 2007 (WRC-07) decision along with point-to-point Fixed Wireless Access (FWA) system, which currently allocated in the same band, the frequency sharing between IMT-Advanced and FWA is essential. This paper investigates the spectrum sharing requirements in different terrestrial areas using interference to noise ratio criterion. Three methods of investigation of the interference, co-channel, null-guard band, and adjacent channel, have been proposed to investigate the phenomenon in the frequency and space domains to obtain correlation between the minimum separated range of base stations antennas and the frequency separation. Offaxis angles direction alignment is also proposed to reduce the necessary coordination separation distance and frequency separation for good enough coexistence between systems. Key-Words: Zero-guard band, Co-channel, Adjacent channel, Interference, I/N ratio, Separation distance, Off-axis angles direction alignment.