Blind source separation with order recovery for MIMO system and an Alamouti or Tarokh space-time block coding scheme

Abstract

We consider the problem of blind sources separation (BSS), i.e., without the use of training sequences, for a multiuser communication system using a linear multiple input multiple output (MIMO) system combined with an Alamouti or Tarokh space-time block coding scheme. In this coding scheme, each symbol is transmitted using several time slots and through a linear instantaneous mixing channel. In order to separate the sources, we use the multiuser kurtosis (MUK) algorithm, usually used in Bell layered space time (BLAST) scheme. This algorithm allows to separate the sources in spite to redundancy insert by Alamouti and Tarokh scheme. So, we propose a new method, applied after MUK algorithm, which raises the ambiguity of sources order inherent in BSS algorithm, thanks to redundancy. Furthermore, it is shown theoretically that using this method reduces the mean square error (MSE) of 3 dB compared with a method which doesn't exploit the redundancy.