Method and apparatus for transmitting and receiving reference signal in wireless communication system
View Patent ↗The present invention relates to a method and an apparatus for transmitting and receiving a reference signal in a wireless communication system. In the method, in order to dynamically switch an uplink (UL) Demodulation-Reference Signal (DM-RS) according to the communication environment, such as CoMP and MU-MIMO, a parameter set for generation of a reference signal sequence is configured to include a Virtual Cell Identifier (VCID) parameter configured by information of a total of 9 bits and a cyclic shift hopping initial value parameter c init CSH , which is 9-bit information representing one integer value among 510 integer values. Therefore, it may be possible to achieve dynamic transmission or reception of a reference signal and channel estimation through the dynamic transmission or reception of the reference signal even when the communication environment dynamically changes as in a Cooperative Multiple Point transmission and reception (CoMP) scenario.
1. A method of transmitting a reference signal by a User Equipment (UE), the method comprising:
receiving an initial value CSH and a cell identifier;
determining a base sequence based on the cell identifier;
initializing a pseudo random sequence generator based on C init , C init being generated based on Eq. 1;
determining a cyclic shift value using a pseudo random sequence generated by the pseudo random sequence generator; and
generating the reference signal based on the cyclic shift value and the base sequence,
wherein:
the initial value is generated based on an integer ranging from 0 to 509,
the cell identifier is generated based on an integer ranging from 0 to 509, and
c
init
=
⌊
c
init
CSH
30
⌋
·
2
5
+
(
c
init
CSH
mod
30
)
.
Eq
.
1
2. The method of claim 1 , wherein the initial value and the cell identifier are received through a Radio Resource Control (RRC) message.
3. A method of transmitting a reference signal by a User Equipment (UE), the method comprising:
receiving an initial value c init CSH ;
initializing a pseudo random sequence generator based on C init ,
determining a cyclic shift value using a pseudo random sequence generated by the pseudo random sequence generator;
generating the reference signal based on a base sequence and the cyclic shift value; and
transmitting the generated reference signal,
wherein C init is generated based on Eq. 1;
c
init
=
⌊
c
init
CSH
30
⌋
·
2
5
+
(
c
init
CSH
mod
30
)
.
Eq
.
1
4. The method of claim 3 , wherein the initial value c init CSH represents one of 510 integer values and is received from a transmission/reception point.
5. The method of claim 3 , wherein the initial value c init CSH is generated based on an integer ranging from 0 to 509.
6. The method of claim 3 , wherein total number of the integer values available for the initial value c init CSH is 510.
7. The method of claim 3 , wherein the initial value c init CSH is received through higher layer signaling.
8. A method of receiving a reference signal by a transmission/reception point, the method comprising:
transmitting an initial value and a cell identifier (ID) to a User Equipment (UE);
receiving the reference signal, from the UE; and
measuring a channel state based on the received reference signal,
wherein:
the reference signal is generated based on a cyclic shift value and a base sequence;
the cyclic shift value is determined by using a pseudo random sequence generated by a pseudo random sequence generator;
the pseudo random sequence generator is initialized based on C init , C init being generated based on Eq. 1;
the base sequence is determined based on the cell ID;
the initial value is generated based on an integer ranging from 0 to 509;
the cell ID is generated based on an integer ranging from 0 to 509; and
c
init
=
⌊
c
init
CSH
30
⌋
·
2
5
+
(
c
init
CSH
mod
30
)
.
Eq
.
1
9. The method of claim 8 , wherein the cell ID is a virtual cell identifier, and
wherein the initial value and the cell ID are transmitted to the UE through higher layer signaling.
10. An apparatus to transmit a reference signal, the apparatus comprising:
a parameter information receiver configured to receive an initial value and a cell identifier (ID); and
a reference signal processor configured to determine a base sequence based on the cell ID, to initialize a pseudo random sequence generator based on C init , C init being generated based on Eq. 1, to determine a cyclic shift value using a pseudo random sequence generated by the pseudo random sequence generator, to generate the reference signal based on the cyclic shift value and the base sequence, and to transmit the generated reference signal,
wherein:
the initial value is generated based on an integer ranging from 0 to 509,
the cell ID is generated based on an integer ranging from 0 to 509, and
c
init
=
⌊
c
init
CSH
30
⌋
·
2
5
+
(
c
init
CSH
mod
30
)
.
Eq
.
1
11. An apparatus to receive a reference signal, the apparatus comprising:
a transmitter configured to transmit an initial value and a cell identifier to a User Equipment (UE);
a receiver configured to receive the reference signal from the UE; and
a channel state measurer configured to measure a channel state of the UE from the received reference signal;
wherein:
the reference signal is generated based on a cyclic shift value and a base sequence;
the cyclic shift value is determined by using a pseudo random sequence generated by a pseudo random sequence generator;
the pseudo random sequence generator is initialized based on C init , C init being generated based on Eq. 1;
the base sequence is determined based on the cell identifier; and
c
init
=
⌊
c
init
CSH
30
⌋
·
2
5
+
(
c
init
CSH
mod
30
)
.
Eq
.
1
12. The apparatus of claim 11 , wherein:
the cell identifier is a virtual cell identifier;
the initial value is generated based on an integer ranging from 0 to 509;
the cell identifier is generated based on an integer ranging from 0 to 509; and
the initial value and the cell identifier are transmitted to the UE through higher layer signaling.