Method and apparatus for transmitting downlink reference signal in wireless communication system that supports multiple antennas
First Claim
1. A method for transmitting reference signals for 8 or fewer antenna ports at a base station, the method comprising:
- transmitting common reference signals (CRSs) for four or fewer antenna ports and channel state information-reference signals (CSI-RSs) for the 8 or fewer antenna ports,wherein the CRSs and the CSI-RSs are mapped to a downlink subframe including a first slot and a second slot,wherein the downlink subframe has an extended cyclic prefix (CP) and has 12 orthogonal frequency division multiplexing (OFDM) symbols, wherein an OFDM symbol index starts from 0,wherein a predetermined pattern for the CSI-RSs includes that the CSI-RSs are mapped to two consecutive OFDM symbols, wherein the two consecutive OFDM symbols are second and third OFDM symbols of the second slot, andwherein the predetermined pattern for the CSI-RSs is allowed to be used only when the CRSs are configured for 2 or fewer antenna ports.
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Abstract
The present invention relates to a wireless communication system, and in particular, to a method and an apparatus for transmitting a downlink reference signal in a wireless communication system that supports multiple antennas. The method for transmitting a reference signal for a maximum of eight antenna ports according to one embodiment of the present invention comprises: in a base station, mapping part of a common reference signal for a maximum of four antenna ports into a downlink subframe that includes a 1st slot and a 2nd slot; in the base station, mapping a channel status information reference signal for the maximum of eight antenna ports into the downlink subframe, according to a preset pattern; and in the base station, transmitting the downlink subframe into which the common reference signal and the channel status information reference signal have been mapped, wherein the preset pattern defines the channel status information reference signal for the maximum of eight antenna ports to be mapped onto two OFDM symbols of the data region in the downlink subframe, and wherein part of the common reference signal for the maximum of four antenna ports is limited to the common reference signal for a maximum of two antenna ports.
24 Citations
13 Claims
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1. A method for transmitting reference signals for 8 or fewer antenna ports at a base station, the method comprising:
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transmitting common reference signals (CRSs) for four or fewer antenna ports and channel state information-reference signals (CSI-RSs) for the 8 or fewer antenna ports, wherein the CRSs and the CSI-RSs are mapped to a downlink subframe including a first slot and a second slot, wherein the downlink subframe has an extended cyclic prefix (CP) and has 12 orthogonal frequency division multiplexing (OFDM) symbols, wherein an OFDM symbol index starts from 0, wherein a predetermined pattern for the CSI-RSs includes that the CSI-RSs are mapped to two consecutive OFDM symbols, wherein the two consecutive OFDM symbols are second and third OFDM symbols of the second slot, and wherein the predetermined pattern for the CSI-RSs is allowed to be used only when the CRSs are configured for 2 or fewer antenna ports. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A method of estimating a channel using channel state information-reference signals (CSI-RSs) for 8 or fewer antenna ports from a base station at a user equipment, the method comprising:
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receiving common reference signals (CRSs) for four or fewer antenna ports and the CSI-RSs for the 8 or fewer antenna ports; and estimating the channel using the CSI-RSs, wherein the CRSs and the CSI-RSs are mapped to a downlink subframe including a first slot and a second slot, wherein the downlink subframe has an extended cyclic prefix (CP) and has 12 orthogonal frequency division multiplexing (OFDM) symbols, wherein an OFDM symbol index starts from 0, wherein a predetermined pattern for the CSI-RSs includes that the CSI-RSs are mapped to two consecutive OFDM symbols, wherein the two consecutive OFDM symbols are second and third OFDM symbols of the second slot, and wherein the predetermined pattern for the CSI-RSs is allowed to be used only when the CRSs are configured for 2 or fewer antenna ports.
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12. A base station for transmitting reference signals (RSs) for 8 or fewer antenna ports, the base station comprising:
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a receiver; a transmitter; and a processor, wherein the processor is configured to transmit common reference signals, (CRSs) for four or fewer antenna ports and channel state information-reference signals (CSI-RSs) for the 8 or fewer antenna ports, wherein the CRSs and the CSI-RSs are mapped to a downlink subframe including a first slot and a second slot, wherein the downlink subframe has an extended cyclic prefix (CP) and has 12 orthogonal frequency division multiplexing (OFDM) symbols, wherein an OFDM symbol index starts from 0, wherein a predetermined pattern for the CSI-RSs includes that the CSI-RSs are mapped to two consecutive OFDM symbols, wherein the two consecutive OFDM symbols are second and third OFDM symbols of the second slot, and wherein the predetermined pattern for the CSI-RSs is allowed to be used only when the CRSs are configured for 2 or fewer antenna ports.
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13. A user equipment for estimating a channel using channel state information-reference signals (CSI-RSs) for 8 or fewer antenna ports from a base station, the user equipment comprising:
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a receiver; a transmitter; and a processor, wherein the processor is configured to; receive common reference signals (CRSs) for four or fewer antenna ports and the CSI-RSs for the 8 or fewer antenna ports; and estimate the channel using the CSI-RSs, wherein the CRSs and the CSI-RSs are mapped to a downlink subframe including a first slot and a second slot, wherein the downlink subframe has an extended cyclic prefix (CP) and has 12 orthogonal frequency division multiplexing (OFDM) symbols, wherein an OFDM symbol index starts from 0, wherein a predetermined pattern for the CSI-RSs includes that the CSI-RSs are mapped to two consecutive OFDM symbols, wherein the two consecutive OFDM symbols are second and third OFDM symbols of the second slot, and wherein the predetermined pattern for the CSI-RSs is allowed to be used only when the CRSs are configured for 2 or fewer antenna ports.
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Specification