Method for generating reference signal sequence in multi-antenna wireless communication system and apparatus for same
The present application discloses a method in which a base station transmits a reference signal sequence in a wireless communication system. In detail, the method comprises the steps of: generating a pseudo-random sequence using a first m-sequence and a second m-sequence; generating the reference signal sequence using the pseudo-random sequence; and transmitting the reference signal to a mobile station via antenna ports different from one another. The second m-sequence has an initial value containing parameters for discriminating reference signal sequences among users.
1. A method for transmitting a UE (User Equipment) specific reference signal sequence in a wireless communication system, the method comprising:
generating the UE specific reference signal sequence based on a pseudo-random sequence (c(n)); and
transmitting the UE specific reference signal sequence to a UE,
wherein the pseudo-random sequence is defined by following equation A,
c ( n )=( x 1 ( n+N C )+ x 2 ( n+N C ))mod 2
x 1 ( n+ 31)=( x 1 ( n+ 3)+ x 1 ( n ))mod 2,
x 2 ( n+ 31)=( x 2 ( n+ 3)+ x 2 ( n+ 2)+ x 2 ( n+ 1)+ x 2 ( n ))mod 2 <equation A>
where N C =1600 and a first m-sequence (x 1 (n)) is initialized with x 1 (0)=1, x 1 (n)=0, n=1, 2, . . . , 30,
wherein a second m-sequence (x 2 (n)) is initialized with k+(└n s /2┘+1)·(2n ID +1)·2 16 , where n s is a slot number within a radio frame, k is a scrambling identity, and n ID is an identity configured based on a transmission mode of a PDSCH (Physical Downlink Shared CHannel).
2. The method according to claim 1 , wherein the UE specific reference signal sequence (r(m)) is defined by following equation B,
r
(
m
)
=
1
2
(
1
-
2
·
c
(
2
m
)
)
+
j
1
2
(
1
-
2
·
c
(
2
m
+
1
)
)
,
〈
equation
B
〉
m=0, 1, . . . , 12N RB PDSCH −1 where N RB PDSCH is a number of resource blocks allocated to the PDSCH.
3. The method according to claim 1 , wherein the scrambling identity (k) is transmitted to the UE through a PDCCH (Physical Downlink Control CHannel).
4. The method according to claim 1 , wherein information on the scrambling identity (k) is included in a DCI (Downlink Control Information) associated with the PDSCH.
5. The method according to claim 1 , wherein the scrambling identity (k) is one or zero.
6. The method according to claim 1 , wherein the UE specific reference signal sequence is transmitted via two antenna ports.
7. A method for receiving a UE (User Equipment) specific reference signal sequence at a UE in a wireless communication system, the method comprising:
receiving the UE specific reference signal sequence,
wherein the UE specific reference signal sequence is generated based on a pseudo-random sequence (c(n)), and
wherein the pseudo-random sequence is defined by following equation A,
c ( n )=( x 1 ( n+N C )+ x 2 ( n+N C ))mod 2
x 1 ( n+ 31)=( x 1 ( n+ 3)+ x 1 ( n ))mod 2,
x 2 ( n+ 31)=( x 2 ( n+ 3)+ x 2 ( n+ 2)+ x 2 ( n+ 1)+ x 2 ( n ))mod 2 <equation A>
where N C =1600 and a first m-sequence (x 1 (n)) is initialized with x 1 (0)=1, x 1 (n)=0, n=1, 2, . . . , 30,
wherein a second m-sequence (x 2 (n)) is initialized with k+(└n s /2┘+1)·(2n ID +1)·2 16 , where n s is a slot number within a radio frame, k is a scrambling identity, and n ID is an identity configured based on a transmission mode of a PDSCH (Physical Downlink Shared CHannel).
8. The method according to claim 7 , wherein the UE specific reference signal sequence (r(m)) is defined by following equation B,
r
(
m
)
=
1
2
(
1
-
2
·
c
(
2
m
)
)
+
j
1
2
(
1
-
2
·
c
(
2
m
+
1
)
)
,
〈
equation
B
〉
m=0, 1, . . . , 12N RB PDSCH −1, where N RB PDSCH is a number of resource blocks allocated to the PDSCH.
9. The method according to claim 7 , wherein the scrambling identity (k) is received through a PDCCH (Physical Downlink Control Channel).
10. The method according to claim 7 , wherein information on the scrambling identity (k) is included in a DCI (Downlink Control Information) associated with the PDSCH.
11. The method according to claim 7 , wherein the scrambling identity (k) is one or zero.
12. The method according to claim 7 , wherein the UE specific reference signal sequence is received via two antenna ports.