Iterative post processing algorithm for channel estimation of multiuser detection based wireless systems

The multiuser detection (MUD) based receiver requires more accurate channel estimation, and hence post processing is required to clean up the channel estimate by eliminating the noise only coefficients after the channel estimation. The iterative post processing method is proposed, which provides more accurate channel responses as well as the background noise variance estimation at the cost of the ignorable processing time compared to the conventional method based on the threshold test with the threshold value relative to the noise variance. The simulation results show that the noise estimation error of the proposed method is less than 10 % depending on the channel environments, which is much smaller than that of the conventional method.