Method and apparatus for transmitting uplink reference signal in a multi-antenna wireless communication system

A User Equipment (UE) configured to transmit signals in a multi-antenna wireless communication system, the UE comprising:

• a processor;
• and
• a memory containing instructions, which when executed by the processor, cause the UE to:
• receive, from a Base Station (BS), a first uplink grant indicating a number of transport blocks and a number of layers for the transport blocks,
• calculate resources of a Reference Signal (RS) for the transport blocks based on a cyclic shift field included in the first uplink grant,
• transmit, to the BS, the transport blocks and the RS for the transport blocks using the calculated resources of the RS,
• receive, from the BS, Negative ACKnowledgment (NACK) information for at least one of the transport blocks for retransmission,
• if a second uplink grant for retransmission is not received from the BS and if a number of the at least one of the transport blocks for retransmission is not equal to the number of transport blocks indicated by the first uplink grant, recalculate the resources of the RS for the at least one of the transport blocks for retransmission based on the cyclic shift field included in the first uplink grant and a number of layers of the at least one of the transport blocks for retransmission, and
• retransmit, to the BS, the at least one of the transport blocks for retransmission and the RS for the at least one of the transport blocks for retransmission using the recalculated resources of the RS,
• wherein the resources of the RS comprise a cyclic shift value and an Orthogonal Cover Code (OCC) value.

A method for receiving signals at a Base Station (BS) in a multi-antenna wireless communication system, the method comprising:

• transmitting, from the BS to a User Equipment (UE), a first uplink grant indicating a number of transport blocks and a number of layers for the transport blocks;
• receiving, by the BS from the UE, the transport blocks and a Reference Signal (RS) for the transport blocks based on the first uplink grant, wherein resources of the RS for the transport blocks are calculated based on a cyclic shift field included in the first uplink grant;
• transmitting, by the BS to the UE, Negative ACKnowledgment (NACK) information for at least one of the transport blocks for retransmission,
• wherein, if a second uplink grant for retransmission is not received by the UE and if a number of the at least one of the transport blocks for retransmission is not equal to the number of transport blocks indicated by the first uplink grant, the resources of the RS for the at least one of the transport blocks for retransmission are recalculated based on the cyclic shift field included in the first uplink grant and a number of layers of the at least one of the transport blocks for retransmission;
• and
• receiving, by the BS from the UE, the at least one of the transport blocks for retransmission and the RS for the at least one of the transport blocks for retransmission using the recalculated resources of the RS,
• wherein the resources of the RS comprise a cyclic shift value and an Orthogonal Cover Code (OCC) value.

A Base Station (BS) configured to receive signals in a multi-antenna wireless communication system, the BS comprising:

• a processor;
• and
• a memory containing instructions, which when executed by the processor, cause the BS to
• transmit, to a User Equipment (UE), a first uplink grant indicating a number of transport blocks and a number of layers for the transport blocks,
• receive, from the UE, the transport blocks and a Reference Signal (RS) for the transport blocks based on the first uplink grant, wherein resources of the RS for the transport blocks are calculated based on a cyclic shift field included in the first uplink grant,
• transmit, to the UE, Negative ACKnowledgment (NACK) information for at least one of the transport blocks for retransmission,
• wherein, if a second uplink grant for retransmission is not received by the UE and if a number of the at least one of the transport blocks for retransmission is not equal to the number of transport blocks indicated by the first uplink grant, the resources of the RS for the at least one of the transport blocks for retransmission are recalculated based on the cyclic shift field included in the first uplink grant and a number of layers of the at least one of the transport blocks for retransmission;
• and
• receive, from the UE, the at least one of the transport blocks for retransmission and the RS for the at least one of the transport blocks for retransmission using the recalculated resources of the RS,
• wherein the resources of the RS comprise a cyclic shift value and an Orthogonal Cover Code (OCC) value.