Implicit MIMO Channel Estimation Without DC-Offset Based on ZCZ Training Sequences

In this letter, an implicit direct current (dc) free multiple-input multiple-output (MIMO) channel estimation scheme is proposed by employing a set of zero correlation zone (ZCZ) training sequences. The new implicit MIMO channel estimation scheme includes, as a special case, the conventional implicit single-input single-output (SISO) channel estimation scheme, which is also considered and analyzed. For implicit SISO channel estimation, by choosing properly a set of ZCZ sequences with balanced property, the harmful dc-offset can be completely removed, thus exhibiting significantly better estimation performance and resulting in simpler implementation when compared with the conventional implicit training schemes without dc-offset elimination and with dc-offset elimination based on perfect sequences, respectively