On the Blind Channel Identifiability of MIMO-STBC Systems Using Noncircular Complex FastICA Algorithm

This paper studies the channel identifiability for Multiple-Input Multiple-Output Space–Time Block Code (MIMO-STBC) systems using the noncircular complex Fast Independent Component Analysis (nc-FastICA) algorithm. In contrast to the previous blind MIMO-STBC channel estimation methods in literature, the method proposed in this paper is more suitable for non-cooperative scenario since it needs less prior knowledge and does not require any modification of the transmitter. The main contribution of the paper consists in the theoretical proof that, although the sources among different antennas of MIMO-STBC systems are not independent, they can be retrieved from the received data by directly using nc-FastICA algorithm in most cases. The conclusion is also demonstrated by simulation. This shows that the classical nc-FastICA algorithm can be applied to a wider range of situations rather than strictly independent sources.