Method for Transmitting Reference Signal for Terminal Demodulation in Radio Mobile Communication System, and Apparatus for Implementing the Same

1. A method for transmitting demodulation reference signals in a radio mobile communication system, the method comprising: mapping, by a base station, the demodulation reference signals for multiple antenna ports to a resource block according to mapping patterns; and transmitting, by the base station to a user equipment, the demodulation reference signals in a downlink subframe, wherein: the mapping patterns are classified as a first pattern group and a second pattern group, the first pattern group corresponds to at least one antenna port among the multiple antenna ports, the second pattern group corresponds to remaining at least one antenna port among the multiple antenna ports, resource element positions of the first pattern group are shifted by 1 subcarrier compared to resource element positions of the second pattern group, and the first pattern group and the second pattern group are defined in a same resource block, and wherein: the first pattern group includes 12 resource element positions in the resource block, and the second pattern group includes another 12 resource element positions in the resource block.

2. The method according to claim 1 , wherein: the resource element positions of the first pattern group are commonly used for the at least one antenna port among the multiple antenna ports; and the resource element positions of the second pattern group are commonly used for the remaining at least one antenna port among the multiple antenna ports.

3. The method according to claim 1 , wherein: the demodulation reference signals of the at least one antenna ports corresponding to the first pattern group are multiplexed using a first set of orthogonal code sequences; and the demodulation reference signals of the remaining at least one antenna ports corresponding to the second pattern group are multiplexed using a second set of orthogonal code sequences.

4. The method according to claim 1 , wherein: the resource element positions of the first pattern group are on 4 orthogonal frequency division multiplexing symbols in the downlink subframe; and the resource element positions of the second pattern group are on the 4 orthogonal frequency division multiplexing symbols in the downlink subframe.

5. The method according to claim 1 , wherein the resource block includes 14 orthogonal frequency division multiplexing symbols and 12 subcarriers.

6. The method according to claim 1 , wherein the demodulation reference signals are used by the user equipment to demodulate downlink data.

7. The method according to claim 1 , wherein a number of the multiple antenna ports is 3 , 4 , 5 , 6 , 7 , or 8 .

8. A base station for transmitting demodulation reference signals in a radio mobile communication system, the base station comprising: a transmitter; a receiver; and a processor is configured to: map the demodulation reference signals for multiple antenna ports to a resource block according to mapping patterns; and transmit, to a user equipment using the transmitter, the demodulation reference signals in a downlink subframe, wherein: the mapping patterns are classified as a first pattern group and a second pattern group, the first pattern group corresponds to at least one antenna port among the multiple antenna ports, the second pattern group corresponds to remaining at least one antenna port among the multiple antenna ports, resource element positions of the first pattern group are shifted by 1 subcarrier compared to resource element positions of the second pattern group, and the first pattern group and the second pattern group are defined in a same resource block, and wherein: the first pattern group includes 12 resource element positions in the resource block, and the second pattern group includes another 12 resource element positions in the resource block.

9. The base station according to claim 8 , wherein: the resource element positions of the first pattern group are commonly used for the at least one antenna port among the multiple antenna ports; and the resource element positions of the second pattern group are commonly used for the remaining at least one antenna port among the multiple antenna ports.

10. The base station according to claim 8 , wherein: the demodulation reference signals of the at least one antenna ports corresponding to the first pattern group are multiplexed using a first set of orthogonal code sequences; and the demodulation reference signals of the remaining at least one antenna ports corresponding to the second pattern group are multiplexed using a second set of orthogonal code sequences.

11. The base station according to claim 8 , wherein: the resource element positions of the first pattern group are on 4 orthogonal frequency division multiplexing symbols in the downlink subframe; and the resource element positions of the second pattern group are on the 4 orthogonal frequency division multiplexing symbols in the downlink subframe.

12. The base station according to claim 8 , wherein the resource block includes: 14 orthogonal frequency division multiplexing symbols; and 12 subcarriers.

13. The base station according to claim 8 , wherein the demodulation reference signals are used by the user equipment to demodulate downlink data.

14. The base station according to claim 8 , wherein a number of the multiple antenna ports is 3 , 4 , 5 , 6 , 7 , or 8 .