On blind channel identifiability under space-time coded transmission

Space-time block coded (STBC) transmission has recently been established as an efficient method to enhance wireless communication performance over quasi-static fading channels. Often, the success of STBC requires accurate channel knowledge at the receiver side. In this work, we present a channel estimation approach that does not require training data to estimate the unknown channel. We establish that under real space-time coded transmission, if the STBC symbol dimension n is odd, then the channel is identifiable up to a scalar ambiguity. In case the STBC dimension is even, the channel matrix is still identifiable if it has full column rank and the number of transmit antennas is odd. We develop simple algorithms to identify the unknown space-time channel matrix for STBC transmission developed.