Schemes for mitigating adjacent channel interference in coexisting TDD-FDD systems

This paper considers the problem of adjacent channel interference between two different operators using different duplexing methods. Focusing on the interference between two colocated base stations, which existing guard-band based methods still cannot solve efficiently, we propose a scheme that adjusts the downlink power of the aggressor system to maximize the downlink transmission capacity while keeping the interference introduced to the victim system in a tolerable range. In addition to the power allocation scheme, a downlink user allocation scheme is proposed to improve further the downlink capacity. Simulations on 2.6-GHz systems show that the proposed schemes enable coexistence of two co-located base stations, and that the frequency spectrum is utilized more efficiently.