  In this letter, we study the reference signal-aided channel estimation
concept which is a crucial requirement to address the realistic performance of
spatial media-based modulation (SMBM) systems where the radio frequency mirrors
are deployed along with the multiple transmit antennas. Accordingly, least
squares and linear minimum mean square error-based channel estimation schemes
are proposed for MBM-based systems for the first time in the literature where
former studies mainly assume either perfect channel state information or an
error model on channel coefficients. In addition, corresponding symbol
detection performance is studied. To measure the efficiency of the proposed
channel estimation approaches, the theoretical upper bounds on average bit
error rate are derived and shown to be well overlapped with the computer
simulations for the medium and high signal-to-noise ratio regions. This study
is important due to the implementation of channel estimation as well as the
theoretical derivation of detection bounds for MBM-based communication systems.
