HARQ in spatial multiplexing MIMO system

A base station in a spatial multiplexing wireless communications system, the base station comprising:

• a transmitter;
• and
• processing circuitry operatively connected to the transmitter and configured to:
• schedule first and second transport blocks for simultaneous transmission during a first transmission interval on first and second data substreams, respectively;
• assign a single re-transmission process identifier for the first transmission interval;
• transmit first scheduling information for the first transmission interval, the first scheduling information comprising the re-transmission process identifier and first disambiguation data;
• schedule the second transport block for re-transmission during a second transmission interval;
• transmit second scheduling information for the second transmission interval, the second scheduling information comprising the re-transmission process identifier and second disambiguation data;
• and
• wherein the first and second disambiguation data indicate whether the re-transmission of the second transport block is scheduled for the first or second data substream.

A mobile terminal in a spatial multiplexing wireless communications system, the mobile terminal comprising:

• a receiver;
• and
• processing circuitry operatively connected to the receiver and configured to:
• receive first and second transport blocks, the first and second transport blocks having been simultaneously transmitted during a first transmission interval on first and second data substreams, respectively;
• receive a re-transmitted one of the first or second transport blocks during a second transmission interval;
• receive first scheduling information for the first transmission interval, the first scheduling information comprising a single re-transmission process identifier and first disambiguation data;
• receive second scheduling information for the second transmission interval, the second scheduling information comprising the re-transmission process identifier and second disambiguation data;
• and
• determine, based on the first and second disambiguation data, whether the re-transmitted one of the first or second transport blocks is scheduled for re-transmission on the first or second data substream.

A method for processing scheduling information in a spatial multiplexing wireless communication system in which first and second transport blocks are scheduled for simultaneous transmission during a first transmission interval on first and second data substreams, respectively, the method comprising:

• receiving first and second transport blocks, the first and second transport blocks having been simultaneously transmitted during a first transmission interval on first and second data substreams, respectively;
• receiving a re-transmitted one of the first or second transport blocks during a second transmission interval;
• receiving first scheduling information for the first transmission interval, the first scheduling information comprising a single re-transmission process identifier and first disambiguation data;
• receiving second scheduling information for the second transmission interval, the second scheduling information comprising the re-transmission process identifier and second disambiguation data;
• and
• determining, based on the first and second disambiguation data, whether the re-transmitted one of the first or second transport blocks is scheduled for re-transmission on the first or second data substream.