The frequency planning for a cellular system enhanced with two-hop fixed relay nodes （FRNs） is investigated. It is assumed that there is no performance-enhancing technique on the base station （BS）-FRN links. Under the assumed condition, two frequency planning schemes are proposed by the principle of reuse partitioning （RP）. The frequency planning schemes are compared with the channel-borrowing-based frequency planning scheme and the conventional frequency planning scheme without relaying. Theoretical analysis and simulation results show that the proposed schemes can improve the service quality for mobile terminals close to cell boundaries and provide better performance over the channel-borrowing-based frequency planning. Finally, to fully exploit the potentials of FRN enhanced cellular system, some performance enhancing techniques on BS-FRN links are indispensable.
