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 at a base station 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 the following equation 1,
c ( n )=( x 1 ( n+N C )+ x 2 ( n+N C ))mod2
x 1 ( n +31)=( x 1 ( n+ 3)+ x 1 ( n ))mod2
x 2 ( n +31)=( x 2 ( n+ 3)+ x 2 ( n+ 2)+ x 2 ( n +1) +x 2 ( n ))mod2, where N c =1600 <equation 1>
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 cell +1)·2 16 where n s is a slot number within a radio frame, N ID cell is a cell identity, and k is a scrambling identity.
2. The method according to claim 1 , wherein the UE specific reference signal sequence (r(m)) is defined by the following equation 2,
r
(
m
)
=
1
2
(
1
-
2
·
c
(
2
m
)
)
+
j
1
2
(
1
-
2
·
c
(
2
m
+
1
)
)
,
m
=
0
,
1
,
…
,
12
N
RB
PDSCH
-
1
,
where
N
RB
PDSCH
<
equation
2
>
is a number of resource blocks allocated to a PDSCH (Physical Downlink Shared CHannel).
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) format 2B associated with a PDSCH (Physical Downlink Shared CHannel).
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 base station in a wireless communication system, the base station comprising:
a processor for generating a UE (User Equipment) specific reference signal sequence based on a pseudo-random sequence (c(n)) and
a transmitting module for transmitting the UE specific reference signal sequence to a UE,
wherein the pseudo-random sequence is defined by the following equation 1,
c ( n )=( x 1 ( n+N C )+ x 2 ( n+N C ))mod2
x 1 ( n +31)=( x 1 ( n+ 3)+ x 1 ( n ))mod2
x 2 ( n +31)=( x 2 ( n+ 3)+ x 2 ( n+ 2)+ x 2 ( n +1) +x 2 ( n ))mod2, where N c =1600 <equation 1>
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) initialized with k+(└n s /2┘+1)·(2N ID cell +1)·2 16 where n s is a slot number within a radio frame, N ID cell is a cell identity, and k is a scrambling identity.
8. The base station according to claim 7 , wherein the UE specific reference signal sequence (r(m)) is defined by following equation 2,
r
(
m
)
=
1
2
(
1
-
2
·
c
(
2
m
)
)
+
j
1
2
(
1
-
2
·
c
(
2
m
+
1
)
)
,
m
=
0
,
1
,
…
,
12
N
RB
PDSCH
-
1
,
where
N
RB
PDSCH
<
equation
2
>
is a number of resource blocks allocated to a PDSCH (Physical Downlink Shared CHannel).
9. The base station according to claim 7 , wherein the scrambling identity (k) is transmitted to the UE through a PDCCH (Physical Downlink Control CHannel).
10. The base station according to claim 7 , wherein information on the scrambling identity (k) is included in a DCI (Downlink Control Information) format 2B associated with a PDSCH (Physical Downlink Shared CHannel).
11. The base station according to claim 7 , wherein the scrambling identity (k) is one or zero.
12. The base station according to claim 7 , wherein the UE specific reference signal sequence is transmitted via two antenna ports.