Method and apparatus for position estimation in wireless communication

1. A method for receiving a positioning reference signal for positioning in a wireless communication system by a user equipment (UE), the method comprising:

receiving, from an eNodeB, a plurality of positioning reference signal sequences composed of identical sequences to which different frequency shift values are respectively applied;

calculating a correlation between the received plurality of positioning reference signal sequences and transmitted positioning reference signal sequences corresponding to the received plurality of positioning reference signal sequences in a time domain; and

determining a time domain index having a highest value from the calculated correlation as a reference time point for positioning,

wherein the different frequency shift values are determined according to the sum of multiplication of an index of each positioning reference signal sequence and a frequency shift interval, and a frequency offset.

2. The method according to claim 1 , wherein the frequency shift interval is determined in such a way that the calculated correlation has only an effective component.

3. The method according to claim 1 , wherein the frequency shift interval is determined as N/M, where N is the number of subcarriers constituting a whole band and M is the number of the positioning reference signal sequences.

4. The method according to claim 1 , wherein the frequency shift interval is determined as └L(N−N/M)/D┘, where N is the number of subcarriers constituting a whole band, M is the number of the positioning reference signal sequences, and D corresponds to a specific time period.

5. The method according to claim 1 , further comprising receiving information about at least one of the number of the positioning reference signal sequences, an OFDM symbol index of a resource in which the positioning reference signal sequences are transmitted, the frequency shift interval, or the frequency offset.

6. The method according to claim 1 , further comprising receiving information about a candidate set of the number of the positioning reference signal sequences and a candidate set of the frequency shift interval, or information about a candidate set of combinations of the number of the positioning reference signal sequences and the frequency shift intervals.

7. The method according to claim 1 , further comprising transmitting information about information about preferred number of positioning reference signal sequences and a preferred frequency shift interval.

8. The method according to claim 1 , wherein the plurality of positioning reference signal sequences are transmitted in different OFDM symbols.

9. A user equipment (UE) configured to receiver a positioning reference signal in a wireless communication system, the UE comprising:

a radio frequency (RF) unit; and

a processor configured to control the RF unit,

wherein:

the processor is configured to receive, from an eNodeB, a plurality of positioning reference signal sequences composed of identical sequences to which different frequency shift values are respectively applied, to calculate a correlation between the received plurality of positioning reference signal sequences and transmitted positioning reference signal sequences corresponding to the received plurality of reference signal sequences in a time domain, and to determine a time domain index having a highest value from the calculated correlation as a reference time point for positioning; and

the different frequency shift values are determined according to the sum of multiplication of an index of each positioning reference signal sequence and a frequency shift interval, and a frequency offset.

10. The UE according to claim 9 , wherein the frequency shift interval is determined in such a way that the calculated correlation has only an effective component.

11. The UE according to claim 9 , wherein the frequency shift interval is determined as N/M, where N is the number of subcarriers constituting a whole band and M is the number of the positioning reference signal sequences.

12. The UE according to claim 9 , wherein the frequency shift interval is determined as └L(N−N/M)/D┘, where N is the number of subcarriers constituting a whole band, M is the number of the positioning reference signal sequences, and D corresponds to a specific time period.

13. The UE according to claim 9 , wherein the processor is configured to receive information about at least one of the number of the positioning reference signal sequences, an OFDM symbol index of a resource in which the positioning reference signal sequences are transmitted, the frequency shift interval, or the frequency offset.

14. The UE according to claim 9 , wherein the processor is configured to receive information about a candidate set of the number of the positioning reference signal sequences and a candidate set of the frequency shift interval, or information about a candidate set of combinations of the number of the positioning reference signal sequences and the frequency shift intervals.

15. The UE according to claim 9 , wherein the processor is configured to transmit information about information about preferred number of positioning reference signal sequences and a preferred frequency shift interval.

16. The UE according to claim 9 , wherein the plurality of positioning reference signal sequences are transmitted in different OFDM symbols.