—Single antenna co-channel interference (CCI) cancellation is a challenge in mobile communication systems, especially for downlink systems. A novel single antenna CCI cancellation algorithm based on lattice reduction (LR) and decision feedback equalization scheme is proposed in this paper. The idea behind the proposed algorithm is to form a multichannel multi-user detection model through over-sampling and then adopts a decision feedback detection method based on LR. Complexity analysis results show that the complexity of the proposed algorithm is quadratic with the memory length of the channels and is nearly independent of the modulation order. Furthermore, simulation results are also presented to indicate the bit error rate performance of the proposed algorithm and its robustness with respect to channel estimation errors.