AbstractIn orthogonal frequency division multiplexing (OFDM) systems, a co‐channel interference (CCI) canceller has been proposed to reduce CCI from other cells. When the received power of the desired and the interference signals is nearly the same, the probability of detection error becomes high. Therefore, even though a convolutional code is employed, performance is not much improved. In this paper, to solve this problem, we propose to apply frequency spread coding (FSC) and/or frequency interleaving (FI) to the CCI canceller for OFDM systems. Performance of the system using FSC or FI is evaluated by computer simulation. Furthermore, the system using FSC to the adjacent subcarriers, which have high correlation, and the system using FSC to the separated subcarriers, which have low correlation, are also compared. Copyright © 2003