The adjacent cell interference (ACI) issue faced when applying multiple user superposition transmission (MUST) scheme to uplink transmission in cellular networks is considered in this article. To dealing with ACI we proposed a novel MUST scheme called interference fusion multiple access (IFMA). In our scheme transmission rate of superimposed ACI is reduced via compute-and-forward framework. As a result the superimposed ACI can be detected with lower complexity and its adverse effect on system performance is minimized. Both theoretical analysis and numerical results show that our scheme outperforms the available MUST schemes in cellular network scenarios.