Due to the defects of the severe pilot pollution exist in the massive Multiple-Input Multiple-Output（MIMO）system when the same pilot sequences are reused by all cells for channel estimation

the paper proposes an enhanced algorithm for channel estimation to alleviate the pilot pollution.In this paper

previous same pilot sequences are replaced by the random pilot sequences for the channel estimation which has the advantages of more accurate uplink channel status information and lower pilot pollution due to the fact that the random pilot sequences are independent and unrelated.The simulation results of the mean square error of the channel estimation show that the proposed method can obviously mitigate the pilot pollution when comparing with the method with the same pilot sequences.