Abstract: In a narrowband network environment, the signals received by the receiver are usually multi-channel mixed signals. For single channel receivers, it is difficult to separate the mixed signals and extract the source signals by using conventional blind source separation method. To solve this problem, this paper proposed a method of single channel blind source separation using Kalman filtering algorithm for signal estimation. This method used the time-series structure between signals and uses the Kalman filter algorithm to continuously estimate and iteratively update the source signal in the multi-signal mixture, finally the signal got separated. Simulation results show that the proposed method can effectively estimate and separate the source signals.