Co-channel and adjacent channel interference evaluation for IMT-Advanced coexistence with existing fixed systems

Due to spectrum scarcity and emerging various wireless applications, coexistence and sharing between IMT-advanced and fixed wireless access (FWA) systems becomes a recently critical issue. At WRC-07, ITU-R allocated 3400-3600 MHz band for the coming fourth generation (4G) or IMT-Advanced on a co-primary basis along with existing FWA systems. Therefore, coexistence and sharing requirements like separation distance and frequency separation coordination must be achieved in terms of both co-channel and adjacent channel frequencies. Co-sited the two base stations antennas and non co-sited coexistence of the two systems are analyzed (depending on interference to noise ratio of -6 dB as a standard coexistence criteria). The interference analysis models, adjacent channel interference ratio ACIR and spectral emission mask (SEM) are applied in the mentioned band to extract the additional isolation needed to protect adjacent channel interference. Finally, possible intersystem interference mitigation techniques are suggested.