Method and device for performing HARQ in a multiple antenna system
Disclosed are a method and a device for performing HARQ in a multiple antenna system. A terminal transmits uplink data via a plurality of antennas and through a Physical Uplink Shared Channel (PUSCH), and receives an ACK/NACK (Acknowledgement/Non-Acknowledgement) signal indicating whether or not the uplink data has been received, the signal being received via the plurality of antennas and through a PHICH (Physical Hybrid-ARQ Indicator Channel) which corresponds to the PUSCH. A downlink resource to which the PHICH is mapped is determined on the basis of the index (I PRB — RA lowest — index ) of the smallest Physical Resource Block (PRB) among the PRBs to which the PUSCH is mapped, uplink DMRS (Demodulation Reference Signal) cyclic shift parameters (n DMRS ) and Orthogonal Code Cover (OCC) index.
1. A method of determining a physical hybrid-ARQ indicator channel (PHICH) resource in a multi-antenna system, the method comprising:
transmitting uplink data through a plurality of antennas on a physical uplink shared channel (PUSCH); and
determining a PHICH resource respectively corresponding to the uplink data,
wherein the PHICH resource is determined based on a lowest physical resource block (PRB) index I PRB — RA lowest — index among PRBs in a first slot to which the PUSCH is mapped, a cyclic shift field n DMRS for an uplink demodulation reference signal (DMRS), and a parameter regarding an orthogonal code cover (OCC),
wherein the PHICH resource is determined based on Equation:
n PHICH group =( I PRB — RA lowest — index +n DMRS +n OCC )mod N PHICH group +I PHICH N PHICH group
n PHICH seq =(└ I PRB — RA lowest — index /N PHICH group ┘+n DMRS +n OCC )mod 2 N SF PHICH ,
where n PHICH group is an index of a PHICH group, n PHICH seq is an orthogonal sequence index in the PHICH group, n DMRS is the cyclic shift field for the uplink DMRS, N SF PHICH is a size of a spreading factor (SF), I PRB — RA lowest — index is the lowest PRB index among PRBs in a first slot to which the PUSCH is mapped, n OCC is an OCC index which is the parameter regarding the OCC, N PHICH group is the number of PHICH groups, and I PHICH is a value 0 or 1, and
wherein the n OCC is either 0 or 1.
2. The method of claim 1 , wherein the parameter regarding the OCC is obtained through a physical downlink control channel (PDCCH) or a radio resource control (RRC) message from a base station.
3. The method of claim 1 , wherein the parameter regarding the OCC is determined based on the cyclic shift field n DMRS for the uplink DMRS.
4. The method of claim 1 , further comprising receiving an acknowledgement/non-acknowledgement (ACK/NACK) signal through the PHICH resource.
5. An apparatus for determining a physical hybrid-ARQ indicator channel (PHICH) resource in a multi-antenna system, the apparatus comprising:
a radio frequency (RF) unit configured for transmitting or receiving a radio signal; and
a processor;
wherein the processor is configured to:
transmit the uplink data through a plurality of antennas on a physical uplink shared channel (PUSCH); and
determining a PHICH resource respectively corresponding to the uplink data,
wherein the PHICH resource is determined based on a lowest physical resource lowest index block (PRB) index I PRB — RA lowest — index among PRBs in a first slot to which the PUSCH is mapped, a cyclic shift field n DMRS for an uplink demodulation reference signal (DMRS), and a parameter regarding an orthogonal code cover (OCC),
wherein the PHICH resource is determined based on Equation:
n PHICH group =( I PRB — RA lowest — index +n DMRS +n OCC )mod N PHICH group +I PHICH N PHICH group
n PHICH seq =(└ I PRB — RA lowest — index /N PHICH group ┘+n DMRS +n OCC )mod 2 N SF PHICH ,
where n PHICH group is an index of a PHICH group, n PHICH seq is an orthogonal sequence index in the PHICH group, n DMRS is the cyclic shift field for the uplink DMRS, N SF PHICH is a size of a spreading factor (SF), I PRB — RA lowest — index is the lowest PRB index among PRBs in a first slot to which the PUSCH is mapped, n OCC is an OCC index which is the parameter regarding the OCC, N PHICH group is the number of PHICH groups, and I PHICH is a value 0 or 1 and wherein n OCC is either 0 or 1.
6. A method of transmitting an acknowledgement/non-acknowledgement (ACK/NACK) signal in a multi-antenna system, the method comprising:
generating a plurality of physical hybrid-ARQ indicator channel (PHICH) sequences;
mapping the plurality of generated PHICH sequences to PHICH resources; and
transmitting the plurality of mapped PHICH sequences to a plurality of user equipments,
wherein the PHICH resources are determined based on a lowest physical resource block (PRB) index I PRB — RA lowest — index among PRBs in a first slot to which respective physical uplink shared channel (PUSCH) corresponding to the respective PHICH sequence are mapped, a cyclic shift field n DMRS for an uplink demodulation reference signal (DMRS),
wherein the PHICH resources do not overlap with each other,
wherein the PHICH resources are determined based on a parameter regarding an orthogonal code cover (OCC) applied to the respective PHICH sequence,
wherein the PHICH resources are determined based on Equation:
n PHICH group =( I PRB — RA lowest — index +n DMRS +n OCC )mod N PHICH group +I PHICH N PHICH group
n PHICH seq =(└ I PRB — RA lowest — index /N PHICH group ┘+n DMRS +n OCC )mod 2 N SF PHICH ,
where n PHICH group is an index of a PHICH group, n PHICH seq is an orthogonal sequence index in the PHICH group, n DMRS is the cyclic shift field for the uplink DMRS, N SF PHICH is a size of a spreading factor (SF), I PRB — RA lowest — index is the lowest PRB index among PRBs in a first slot to which the PUSCH is mapped, n OCC is an OCC index which is the parameter regarding the OCC, N PHICH group is the number of PHICH groups, and I PHICH is a value 0 or 1, and
wherein n OCC is either 0 or 1.
7. The method of claim 6 , wherein the parameter regarding the OCC is obtained through a physical downlink control channel (PDCCH) or a radio resource control (RRC) message from a base station.
8. The method of claim 6 , wherein the parameter regarding the OCC is determined based on the cyclic shift field n DMRS for the uplink DMRS.