Method of switching a periodic/aperiodic transmission of a channel estimation reference signal, and apparatus and method for a transmitting/receiving channel estimation reference signal using the same

1. A method of switching periodic transmission and aperiodic transmission of a channel estimation reference signal for scheduling resources in a communication system, the method comprising:

determining a periodic transmission section where the channel estimation reference signal is periodically transmitted, and an aperiodic transmission section where the channel estimation reference signal is aperiodically transmitted; and

generating and transmitting a periodic/aperiodic indicator to distinguish the periodic transmission section and the aperiodic transmission section, or a transmission indicator including the periodic/aperiodic indicator,

wherein the transmission indicator is formed of two or more bits, and

wherein the transmission indicator comprises the periodic/aperiodic indicator of one or more bits indicating whether a corresponding subframe belongs to the periodic transmission section or the aperiodic transmission section, and a trigger indicator of one bit indicating whether to activate transmission of a channel estimation reference signal in the corresponding subframe.

2. The method as claimed in claim 1 , wherein the periodic/aperiodic indicator or the transmission indicator is transmitted at time intervals, the time interval being sufficient for adaptation to a dynamic environment that requires switching between the periodic transmission and aperiodic transmission.

3. The method as claimed in claim 2 , wherein the periodic/aperiodic indicator or the transmission indicator is transmitted through a physical layer (L1) signaling or a data link layer (L2) signaling.

4. The method as claimed in claim 3 , wherein the periodic/aperiodic indicator or the transmission indicator is included in a separately defined downlink control information (DCI) format, and is transmitted through a physical downlink control channel (PDCCH).

5. The method as claimed in claim 1 , wherein the periodic/aperiodic indicator or the transmission indicator including the periodic/aperiodic indicator is set to transmit a channel estimation reference signal in only aperiodic transmission subframes corresponding to a few subframes in the aperiodic transmission section.

6. The method as claimed in claim 5 , wherein the aperiodic transmission subframe is selected within a characterized range of subframes from among a plurality of subframes in the aperiodic transmission section.

7. The method as claimed in claim 1 , wherein, for a periodic transmission user equipment (UE) to which only the periodic transmission section is applied, excluding an aperiodic transmission UE to which the aperiodic transmission section is applied, the method further comprises:

transmitting, by the periodic transmission UE, an Off trigger indicator that indicates to not transmit a channel estimation reference signal in a subframe where the aperiodic transmission UE transmits a channel estimation reference signal.

8. An apparatus for receiving a channel estimation reference signal for scheduling resources in a communication system, the apparatus comprising:

a periodic/aperiodic indicator processing unit to determine whether switching between a periodic transmission mode and an aperiodic transmission mode for a channel estimation reference signal is required, and to generate and transmit a periodic/aperiodic indicator of one or more bits instructing switching of a mode or a transmission indicator of two or more bits including the periodic/aperiodic indicator; and

a channel estimation reference signal receiving unit to periodically and aperiodically receive a channel estimation reference signal transmitted from a corresponding apparatus, based on the periodic/aperiodic indicator or the transmission indicator,

wherein the periodic/aperiodic indicator of one or more bits indicates whether a corresponding subframe belongs to a periodic transmission section or an aperiodic transmission section, and

wherein the transmission indicator comprises a trigger indicator of one bit indicating whether to activate transmission of a channel estimation reference signal in the corresponding subframe.

9. An apparatus for transmitting a channel estimation reference signal for scheduling resources in a communication system, the apparatus comprising:

a periodic/aperiodic indicator receiving/analyzing unit to receive a transmission indicator including a periodic/aperiodic indicator of one or more bits, to determine a predetermined subframe in a periodic transmission section to be a periodic channel estimation reference signal transmission subframe based on the transmission indicator, and to determine a predetermined subframe in an aperiodic transmission section to be an aperiodic channel estimation reference signal transmission subframe based on the transmission indicator;

a channel estimation reference signal generating unit to generate a channel estimation reference signal; and

a channel estimation reference signal transmitting unit to perform mapping of the generated channel estimation reference signal on the periodic channel estimation reference signal transmission subframe and the aperiodic channel estimation reference signal transmission subframe, for transmission,

wherein the periodic/aperiodic indicator of one or more bits indicates whether a corresponding subframe belongs to the periodic transmission section or the aperiodic transmission section, and

wherein the transmission indicator further comprises a trigger indicator of one bit indicating whether to activate transmission of a channel estimation reference signal in the corresponding subframe.

10. A method of receiving a channel estimation reference signal for scheduling resources in a communication system, the method comprising:

scheduling a periodic channel estimation reference signal transmission section and an aperiodic channel estimation reference signal transmission section, with respect to a predetermined UE;

generating a transmission indicator including a periodic/aperiodic indicator of one or more bits, and transmitting the transmission indicator to the UE; and

receiving a channel estimation reference signal periodically and aperiodically, from the corresponding UE,

wherein the periodic/aperiodic indicator of one or more bits indicates whether a corresponding subframe belongs to a periodic transmission section or an aperiodic transmission section, and

wherein the transmission indicator further comprises a trigger indicator of one bit indicating whether to activate transmission of a channel estimation reference signal in the corresponding subframe.

11. A method of transmitting a channel estimation reference signal for scheduling resources in a communication system, the method comprising:

receiving a transmission indicator including a periodic/aperiodic indicator of one or more bits;

determining a predetermined subframe in a periodic transmission section to be a periodic channel estimation reference signal transmission subframe based on the transmission indicator, and determining a predetermined subframe in an aperiodic transmission section to be an aperiodic channel estimation reference signal transmission subframe based on the transmission indicator; and

transmitting the channel estimation reference signal by including the channel estimation reference in the determined periodic channel estimation reference signal transmission subframe and the aperiodic channel estimation reference signal transmission subframe,

wherein the periodic/aperiodic indicator of one or more bits indicates whether a corresponding subframe belongs to the periodic transmission section or the aperiodic transmission section, and

wherein the transmission indicator further comprises a trigger indicator of one bit indicating whether to activate transmission of a channel estimation reference signal in the corresponding subframe.