Method for transmitting and receiving channel state information periodically or aperiodically

1. A method for aperiodically transmitting channel state information (CSI) by a terminal, the method comprising:

receiving an indicator requesting a channel state information report of a downlink channel from a base station over a downlink control channel; and

aperiodically transmitting the channel state information (CSI) to the base station over a physical uplink shared channel (PUSCH) in subframe n+k, upon receiving the indicator from the base station in subframe n, wherein k is a predetermined number of subframes,

wherein a Cyclic Redundancy Check (CRC) is attached to a transmission control signal including the channel state information (CSI), in order to detect a CRC error from the transmission control signal, such that the transmission control signal including the CRC is transferred over the PUSCH.

2. The method according to claim 1 , wherein the channel state information (CSI) includes at least one of a precoding matrix index (PMI), a channel quality indicator (CQI), and a rank indicator (RI).

3. The method according to claim 1 , wherein the CRC is attached to the transmission control signal including the channel state information (CSI) when the channel state information (CSI) falls within a category defined based on at least one of

a control information multiplexing scheme,

an amount of information of the CSI, and

a requested reliability.

4. The method according to claim 1 , further comprising:

periodically transmitting the channel state information (CSI) to the base station over a physical uplink control channel (PUCCH).

5. The method according to claim 4 , wherein the physical uplink control channel (PUCCH) has an error detection capability weaker than that of the physical uplink shared channel (PUSCH).

6. The method according to claim 1 , wherein k=4.

7. The method according to claim 1 , wherein the channel state information includes a wideband precoding matrix index and a subband precoding matrix index, in which

if the subband precoding matrix index is transferred, a precoding matrix index for each subband is cyclically transmitted in an entire system band or is transferred according to a predetermined order configured by an upper layer higher than a physical layer.

8. A method for allowing a base station to aperiodically receive channel state information (CSI) from a terminal, the method comprising:

transmitting an indicator requesting a channel state information report of a downlink channel to the terminal over a downlink control channel in subframe n; and

aperiodically receiving a report of the channel state information (CSI) from the terminal over a physical uplink shared channel (PUSCH) in subframe n+k, wherein k is a predetermined number of subframes,

wherein a Cyclic Redundancy Check (CRC) is attached to a transmission control signal including the channel state information (CSI), in order to detect a CRC error from the transmission control signal, such that the transmission control signal including the CRC is transferred over the PUSCH.

9. The method according to claim 8 , wherein the CRC is attached to the transmission control signal including the channel state information (CSI) when the channel state information (CSI) falls within a category defined based on at least one of

a control information multiplexing scheme,

an amount of information of the CSI, and

a requested reliability.

10. The method according to claim 8 , further comprising:

periodically receiving the channel state information (CSI) from the terminal over a physical uplink control channel (PUCCH).