A new method of source separation problems: turbo deflation

Abstract

Recently the space-time codes were introduced. They allow significant profits of performances (J. Foschini et al., March 1996) (V. Tarokh et al., 1998,1999). They consist in using several transmitting antennas and sending the signal on sensor network. The transmitted information is then coded differently on each of the sending antennas. Thus, relevant codes could be highlighted for Rayleigh channels. When the channel is very dispersive, it is impossible to use space-time codes developed within the framework of numerical communications on Rayleigh channel. In this paper, we propose a new method (without training sequence) allowing to take part of emission diversity in the numerical communication context on multipath channels. A communication system having 2 emitting antennas and P received antennas over a frequency selective channel is implemented. Each antenna send the same information but coded differently. The problem is then identified as a sensor blind separation problem : it consists in emitting the transmitted symbols sent by the first antenna and those sent by the second antenna.