Single Carrier — Frequency Domain Multiple Access (SC-FDMA) is a multiple access technique employed in LTE uplink transmission. SC-FDMA can improve system throughput by frequency selective scheduling (FSS). In cellular systems using SC-FDMA in the uplink, interference arising from user equipments (UEs) in neighboring cells degrades the system throughput, especially the throughput of cell-edge UEs. In order to overcome this drawback, many papers have considered fractional frequency reuse (FFR) techniques and analyzed their effectiveness. However, these studies have come to different conclusions regarding the effectiveness of FFR because the throughput gain of FFR depends on the frequency reuse design and evaluation conditions. Previous papers have focused on the frequency reuse design. Few papers have examined the conditions where FFR is effective, and only the UE traffic conditions have been evaluated. This paper reveals other conditions where FFR is effective by demonstrating the throughput gain of FFR. In order to analyze the throughput gain of FFR, we focus on the throughput relationship between FFR and FSS. System level simulation results demonstrate that FFR is effective when the following conditions are met: (i) the number of UEs is small and (ii) the multipath delay spread is large or close to 0.