<FONT face=Verdana>This paper addresses the problem of multiple-input multiple-output (MIMO) frequency selective channel estimation using implicit training without dc-offset (direct current). In order to remove the dc-offset directly without in troducing extra complexity

the ZCZ (Zero correlation zone) set with balance properties can be used as training sequences. Since the transmitted data from each antenna is first preprocessed and then arithmetically added onto the training s equences

thus the influence of the unknown data to the channel estimation existed in normal implicit method can be cancelled. In this paper

error variance of channel estimation vector is derived

and time-domain analysis is performed. Our theoretical analysis and simulation results validate the superiority of the new method compared with the conventional implicit estimation method.