On Frequency Separation among Radio Access Technologies in Heterogeneous Networks

In this paper, we study the coexistence of typical radio access technologies (WiMAX, CDMA, WLAN) in heterogeneous networks. Although the radio accesses employ different frequency band, they can interfere with each other due to out-of- band emission. We compute the minimum adjacent channel interference ratio (ACIR) to satisfy the allowable level of interference, and the resulting minimum frequency separation (guard band) between interfering and victim system. We observe that WiMAX-WLAN coexistence and WiMAX-CDMA coexistence are feasible with at least 20 MHz and 15 MHz guard bands, respectively.