US Patent 8386876 Transmission of different redundancy versions on different degrees of freedom

For downlink cooperative multi-point (CoMP) communication, each cooperating transmission point (e.g., base station) may send a retransmission packet with a different redundancy version to a user equipment (UE). Mechanisms may be provided to determine which transmission point should send packets with which redundancy version. For uplink CoMP, in order to reduce the backhaul overhead, each cooperating base station may share only a fraction of the retransmitted packet with the serving base station. Also, different retransmission packets with different redundancy versions can be transmitted to different cooperating base stations using spatial degrees of freedom.