A cooperative communications system comprising a source terminal, at least one relay terminal and a destination terminal. The system also comprises a distributed turbocoder over the source terminal and at least the relay terminal. The first part of the turbocoder residing on the source terminal and/or the second part of the turbocoder residing on the relay terminal is(are) equipped with a frequency scheduler (FSr,FSs) allocating the deeper-fading carriers to the systematic information data and the weaker-fading carriers to the parity data.