Method and apparatus for transmitting positioning reference signal in wireless access system supporting machine type communication
The present invention provides methods for configuring and transmitting a positioning reference signal (PRS) used for estimating the location of a machine type communication (MTC) terminal in a wireless access system supporting machine type communication (MTC), and an apparatus for supporting the same. According to one embodiment of the present invention, a method for transmitting, by a base station, a positioning reference signal (PRS) used for estimating the location of a machine type communication (MTC) terminal in a wireless access system supporting MTC, comprises the steps of: repeating transmission of a physical downlink shared channel (PDSCH) including the same downlink data N times; and transmitting the PRS in a PRS subframe (SF), wherein when the PRS SF consists of a normal subframe (SF) and a multimedia broadcast multicast service single frequency network (MBSFN) SF, a normal cyclic prefix (CP) is used as a CP to be applied to the PRS, and when the PRS SF consists of only the MBSFN SF, a CP applied to the PRS may be an extended CP.
1. A method for transmitting a Positioning Reference Signal (PRS) for estimating a location of a Machine Type Communication (MTC) User Equipment (UE) by a Base Station (BS) in a wireless access system supporting MTC, the method comprising:
transmitting PRS Subframe (SF) information;
repeatedly transmitting a Physical Downlink Shared Channel (PDSCH) including a same downlink data, N times; and
transmitting the PRS in PRS SFs,
wherein a normal Cyclic Prefix (CP) is applied to the PRS when the PRS SFs are configured with a normal SF and a Multimedia Broadcast Multicast Service Single Frequency Network (MBSFN) SF,
wherein an extended CP is applied to the PRS when the PRS SFs are configured with only MBSFN SFs, and
wherein the PRS SF information indicates SFs configured as the PRS SFs.
2. The method according to claim 1 , wherein the repeatedly transmitted PDSCH is not transmitted in the MBSFN SF.
3. The method according to claim 2 , wherein a Redundancy Version (RV) of the PDSCH transmitted repeatedly N times is not counted for the MBSFN SF, if the PDSCH is not transmitted in the MBSFN SF.
4. The method according to claim 2 , wherein a redundancy value (RV) of the PDSCH transmitted repeatedly N times is counted, on the assumption that the PDSCH is transmitted in the MBSFN SF.
5. The method according to claim 1 , wherein if some of the N transmitted PDSCHs are transmitted in the MBSFN SF, the some of the N transmitted PDSCHs are transmitted based on a Demodulation Reference Signal (DM-RS) specific to the MTC UE, and ones of the N transmitted PDSCHs that are transmitted in the normal SF are transmitted based on a Cell-specific Reference Signal (CRS) specific to the BS.
6. A Base Station (BS) for transmitting a Positioning Reference Signal (PRS) for estimating a location of a Machine Type Communication (MTC) User Equipment (UE) in a wireless access system supporting MTC, the BS comprising:
a transmitter; and
a processor configured to support PRS transmission by controlling the transmitter,
wherein the processor is configured to transmit PRS Subframe (SF) information, repeatedly transmit a Physical Downlink Shared Channel (PDSCH) including a same downlink data, N times, and transmit the PRS in PRS SFs,
wherein a normal Cyclic Prefix (CP) is applied to the PRS when the PRS SFs are configured with a normal SF and a Multimedia Broadcast Multicast Service Single Frequency Network (MBSFN) SF,
wherein an extended CP is applied to the PRS when the PRS SFs include only MBSFN SFs, and
wherein the PRS SF information indicates SFs configured as the PRS SFs.
7. The BS according to claim 6 , wherein the repeatedly transmitted PDSCH is not transmitted in the MBSFN SF.
8. The BS according to claim 7 , wherein a Redundancy Version (RV) of the PDSCH transmitted repeatedly N times is not counted for the MBSFN SF, if the PDSCH is not transmitted in the MBSFN SF.
9. The BS according to claim 7 , wherein a redundancy value (RV) of the PDSCH transmitted repeatedly N times is counted, on the assumption that the PDSCH is transmitted in the MBSFN SF.
10. The BS according to claim 6 , wherein if some of the N transmitted PDSCHs are transmitted in the MBSFN SF, the some of the N transmitted PDSCHs are transmitted based on a Demodulation Reference Signal (DM-RS) specific to the MTC UE, and ones of the N transmitted PDSCHs that are transmitted in the normal SF is transmitted based on a Cell-specific Reference Signal (CRS) specific to the BS.