Cellular capacity gains of cooperative MIMO transmission in the downlink

In this paper cooperation among users at the physical layer level is studied for the downlink. Distributed space time linear dispersion codes are proposed for the cooperative strategies amplify and forward (AF) and decode forward (DF), assuming no channel state knowledge at the transmitter. Both AF and DF strategies are evaluated in a cellular multiuser realistic scenario based on TDMA access, considering cellular reuse of the relay slot. Different configurations regarding the number of antennas at the relay and destination nodes are considered. The maximum achievable rate of cooperative schemes implemented by means of space time linear dispersion codes is compared with the theoretical capacity of the cooperative channel. Finally an analysis in terms of BER is given for different schemes.