Apparatus and method for generating and transceiving reference signal in wireless communication system using plural component carriers
View Patent ↗The present invention relates to an apparatus and a method for composing and transmitting/receiving a reference signal in a wireless communication system that uses a plurality of component carriers (CC). In a wireless communication system using a plurality of component carriers, the present invention can reduce an increase in cubic metric (CM) and peak to average power ratio (PAPR) which occur in the course of composing and transmitting/receiving the same reference signal for each component carrier, by composing and transceiving a distinctive reference signal for each component carrier.
1. A method for transmitting a reference signal in a wireless communication system using at least two component carriers, the method comprising:
generating a reference signal enabling discrimination for each component carrier by using a reference signal sequence enabling discrimination for each component carrier; and
transmitting the reference signal enabling the discrimination for each component carrier for each relevant component carrier,
wherein, in generating of the reference signal, a base sequence is constructed based on a Zadoff-Chu sequence, phase cyclic shift is performed on the constructed base sequence, and a reference signal sequence r u,v (α) (n) is constructed,
wherein the reference signal enabling the discrimination for each component carrier is generated by using the reference signal sequence, which is generated by generating the Zadoff-Chu sequence different according to each component carrier and constructing the different base sequences, or by causing a phase cyclic shift value α to be different according to each component carrier.
2. The method as claimed in claim 1 , wherein generating of the Zadoff-Chu sequence different according to each component carrier and constructing of the different base sequences comprises: generating the base sequences r u,v (α) (n), which are different by causing a root value q of the Zadoff-Chu sequence or a sequence group number u constructing the root value q of the Zadoff-Chu sequence to have a difference by adding a component carrier number or an offset value for each component carrier.
3. The method as claimed in claim 2 , wherein the root value q of the Zadoff-Chu sequence different according to each component carrier by adding the component carrier number or the offset value for each component carrier is expressed by
q =(└ q + ½┘+ v ·(−1) └2 q ┘ +N CC )mod N ZC RS and
q =N ZC RS ·( u+ 1)/31,
wherein u represents a sequence group number, v represents a base sequence number in a relevant group, N CC represents each component carrier number or the offset value for each component carrier, and N ZC RS represents a length of the Zadoff-Chu sequence.
4. The method as claimed in claim 2 , wherein the sequence group number u different according to each component carrier by adding the component carrier number or the offset value for each component carrier is expressed by
u =( f gh ( n s )+ f ss +N CC )mod 30,
wherein f gh (n s ) represents a group hopping pattern, f ss represents a sequence shift pattern, and N CC represents each component carrier number or the offset value for each component carrier.
5. The method as claimed in claim 2 , wherein the sequence group number u different according to each component carrier by adding the component carrier number or the offset value for each component carrier is expressed by
u =( f gh ( n s ,N ID CC )+ f ss )mod 30,
wherein f ss represents a sequence shift pattern, N CC represents each component carrier number or the offset value for each component carrier, and f gh (n s , N ID CC ) represents a group hopping pattern expressed by
f
gh
(
n
s
,
N
CC
)
=
{
0
if
group
hopping
is
disabled
(
∑
i
=
0
7
c
(
160
N
CC
+
8
n
s
+
i
)
·
2
i
)
mod
30
if
group
hopping
is
enabled
.
6. The method as claimed in claim 2 , wherein the sequence group number u different according to each component carrier by adding the component carrier number or the offset value for each component carrier is expressed by
u =( f gh ( n s )+ f ss )mod 30,
wherein f ss represents a sequence shift pattern, and f gh (n s ) represents a group hopping pattern expressed by
f
gh
(
n
s
)
=
{
0
if
group
hopping
is
disabled
(
∑
i
=
0
7
c
(
8
n
s
+
i
)
·
2
i
)
mod
30
if
group
hopping
is
enabled
,
wherein an initial value of f gh (n s ) is expressed by
c
init
=
N
CC
·
2
s
+
⌊
N
ID
cell
30
⌋
,
wherein N CC represents each component carrier number or the offset value for each component carrier, and N ID cell represents a cell identifier (ID).
7. The method as claimed in claim 2 , wherein the reference signal corresponds to a reference signal for a physical uplink control channel (PUCCH), and the sequence group number u different according to each component carrier by adding the component carrier number or the offset value for each component carrier is expressed by
u =( f gh ( n s )+ f ss )mod 30,
wherein f gh (n s ) represents a group hopping pattern,
and f ss represents a sequence shift pattern expressed by f ss PUCCH =(N ID cell +N CC ) mod 30,
wherein N CC represents each component carrier number or the offset value for component carrier, and N ID cell represents a cell identifier (ID).
8. The method as claimed in claim 1 , wherein, in generating of the reference signal, the reference signal enabling the discrimination for each component carrier is generated by using the reference signal sequence generated by causing the phase cyclic shift value α to be different according to each component carrier by adding the component carrier number or the offset value for each component carrier.
9. The method as claimed in claim 8 , wherein the reference signal corresponds to a demodulation reference signal (DM-RS) for a physical uplink shared channel (PUSCH), and the phase cyclic shift value α different according to each component carrier by adding the component carrier number or the offset value for each component carrier, is expressed by α=2πn cs /12,
wherein n cs is expressed by n cs =(n DMRS (1) +n DMRS (2) +n PRS (n s )+N CC )mod 12,
wherein n DMRS (1) and n DMRS (2) are determined by a cyclic shift value descending from an upper side and a cyclic shift value for a downlink control information (DCI) format 0, respectively, N CC represents each component carrier number or the offset value for each component carrier, and n PRS (n s ) is expressed by n PRS (n s )=Σ i=0 7 c(8N symb UL ·n s +i)·2 i ,
wherein N symb UL signifies the number of symbols in uplink.
10. The method as claimed in claim 8 , wherein the reference signal corresponds to a DM-RS for a PUSCH, and the phase cyclic shift value α different according to each component carrier by adding the component carrier number or the offset value for each component carrier, is expressed by α=2πn cs /12,
wherein n cs is expressed by n cs =(n DMRS (1) +n DMRS (2) +n PRS (n s ))mod 12,
wherein n DMRS (1) and n DMRS (2) are determined by a cyclic shift value descending from an upper side and a cyclic shift value for a DCI format 0, respectively, and n PRS (n s ) is expressed by n PRS (n s ,N CC )=Σ i=0 7 c(160N symb UL ·N CC +8N symb UL ·n s +i)·2 i ,
wherein N symb UL signifies the number of symbols in uplink, and N CC represents each component carrier number or the offset value for each component carrier.
11. The method as claimed in claim 8 , wherein the reference signal corresponds to a DM-RS for a PUSCH, and the phase cyclic shift value α different according to each component carrier by adding the component carrier number or the offset value for each component carrier, is expressed by α=2πn cs /12,
wherein n cs is expressed by n cs =(n DMRS (1) +n DMRS (2) +n PRS (n s ))mod 12,
wherein n DMRS (1) and n DMRS (2) are determined by a cyclic shift value descending from an upper side and a cyclic shift value for a DCI format 0, respectively, and n PRS (n s ) is expressed by n PRS (n s )=Σ i=0 7 c(8N symb UL ·n s +i)·2 i ,
wherein N symb UL signifies the number of symbols in uplink, and an initial value c(i) is expressed by
c
init
=
N
CC
·
2
10
+
⌊
N
ID
cell
30
⌋
·
2
s
+
f
ss
PUSCH
,
wherein N CC represents each component carrier number or the offset value for each component carrier, N ID cell represents a cell ID, and f ss PUSCH represents a sequence shift pattern for a PUSCH.
12. The method as claimed in claim 8 , wherein the reference signal corresponds to a demodulation reference signal (DM-RS) for a physical uplink control channel (PUCCH), and the phase cyclic shift value α different according to each component carrier by adding the component carrier number or the offset value for each component carrier, is expressed by α(n s ,l)=2π· n cs (n s ,l)/N sc RB ,
wherein N sc RB signifies the number of subcarriers per resource block, and n cs (n s ,l) is expressed by
(
n
s
,
1
,
N
CC
)
=
{
[
n
cs
cell
(
n
s
,
1
)
+
(
n
′
(
n
s
)
·
Δ
shift
PUCCH
+
(
n
_
oc
(
n
s
)
mod
Δ
shift
PUCCH
)
)
modN
′
+
N
CC
]
mod
N
sc
RB
[
n
cs
cell
(
n
s
,
1
)
+
(
n
′
(
n
s
)
·
Δ
shift
PUCCH
+
n
_
oc
(
n
s
)
)
mod
N
′
+
N
CC
]
mod
N
sc
RB
,
wherein an upper part represents a normal cyclic prefix, a lower part represents an extended cyclic prefix, n oc (n s ) represents an orthogonal sequence index, Δ shift PUCCH represents a PUCCH shift parameter descending from a system on an upper side, n′(n s ) and N′ represent parameters determined by setting values in a system, N CC represents each component carrier number or the offset value for each component carrier, and n cs cell (n s ,l) is expressed by
n cs cell ( n s ,l )=Σ i=0 7 c (8 N symb UL ·n s +8 l+i )·2 i ,
wherein N symb UL signifies the number of symbols in uplink.
13. The method as claimed in claim 8 , wherein the reference signal corresponds to a DM-RS for a PUCCH, and the phase cyclic shift value α different according to each component carrier by adding the component carrier number or the offset value for each component carrier, is expressed by α(n s ,l)=2π· n cs (n s ,l)/N sc RB ,
wherein N sc RB signifies the number of subcarriers per resource block, and n cs (n s ,l) is expressed by
n
_
cs
(
n
s
,
1
)
=
{
[
n
cs
cell
(
n
s
,
1
)
+
(
n
′
(
n
s
)
·
Δ
shift
PUCCH
+
(
n
_
oc
(
n
s
)
mod
Δ
shift
PUCCH
)
)
mod
N
′
]
mod
N
sc
RB
[
n
CS
cell
(
n
s
,
1
)
+
(
n
′
(
n
s
)
·
Δ
shift
PUCCH
+
n
_
oc
(
n
s
)
)
mod
N
″
]
mod
N
sc
RB
,
wherein an upper part represents a normal cyclic prefix, a lower part represents an extended cyclic prefix, n oc (n s ) represents an orthogonal sequence index, Δ shift PUCCH represents a PUCCH shift parameter descending from a system on an upper side, n′(n s ) and N′ represent parameters determined by setting values in a system, and n cs cell (n s ,l) is expressed by
n cs cell ( n s ,l,N CC )=Σ i=0 7 c (160 N symb UL ·N CC +8 N symb UL ·n s +8 l+i )·2 i ,
wherein N symb UL signifies the number of symbols in uplink, and N CC represents each component carrier number or the offset value for each component carrier.
14. The method as claimed in claim 8 , wherein the reference signal corresponds to a DM-RS for a PUCCH, and the phase cyclic shift value α different according to each component carrier by adding the component carrier number or the offset value for each component carrier, is expressed by α(n s ,l)=2π· n cs (n s ,l)/N sc RB ,
wherein N sc RB signifies the number of subcarriers per resource block, and n cs (n s ,l) is expressed by
n
_
cs
(
n
s
,
1
)
=
{
[
n
cs
cell
(
n
s
,
l
)
+
(
n
′
(
n
s
)
·
Δ
shift
PUCCH
+
(
n
_
oc
(
n
s
)
mod
Δ
shift
PUCCH
)
)
mod
N
′
]
mod
N
sc
RB
[
n
cs
cell
(
n
s
,
1
)
+
(
n
′
(
n
s
)
·
Δ
shift
PUCCH
+
n
_
oc
(
n
s
)
)
mod
N
″
]
mod
N
sc
RB
,
wherein an upper part represents a normal cyclic prefix, a lower part represents an extended cyclic prefix, n Os (n s ) represents an orthogonal sequence index, Δ shift PUCCH represents a PUCCH shift parameter descending from a system on an upper side, n′(n s ) and N′ represent parameters determined by setting values in a system, and n cs cell (n s ,l) is expressed by n cs cell (n s ,l)=Σ i=0 7 c(8N symb UL ·n s +8l+i)·2 i ,
wherein N symb UL signifies the number of symbols in uplink, and an initial value is expressed by c init =N CC ·2 9 +N ID cell ,
wherein N CC represents each component carrier number or the offset value for each component carrier, and N ID cell represents a cell ID.
15. The method as claimed in claim 8 , wherein the reference signal corresponds to a sounding reference signal (SRS), and the phase cyclic shift value α different according to each component carrier by adding the component carrier number or the offset value for each component carrier, is expressed by α=2π·{(n SRS CS +N CC )mod 8}/8,
wherein n SRS CS has a value determined as one of 0, 1, 2, 3, 4, 5, 6 and 7 by an upper side, and N CC represents each component carrier number or the offset value for each component carrier.
16. An apparatus for transmitting a reference signal in a wireless communication system using at least two component carriers, the apparatus comprising:
a reference signal generator for generating a reference signal enabling discrimination for each component carrier by using a reference signal sequence enabling discrimination for each component carrier; and
a reference signal transmitter for transmitting the reference signal enabling the discrimination for each component carrier, which has been generated by the reference signal generator, for each relevant component carrier,
wherein the reference signal generator configures a base sequence based on a Zadoff-Chu sequence, performs phase cyclic shift on the constructed base sequence, and constructs a reference signal sequence r u,v (α) (n), and
the reference signal generator generates the reference signal enabling the discrimination for each component carrier by using the reference signal sequence, which is generated by generating the Zadoff-Chu sequence different according to each component carrier and constructing the different base sequences, or by causing a phase cyclic shift value α to be different according to each component carrier.
17. The apparatus as claimed in claim 16 , wherein the reference signal generator generates the reference signal enabling the discrimination for each component carrier by using a reference signal sequence, which is generated by constructing a base sequence different according to each component carrier by adding a component carrier number or an offset value for each component carrier based on the Zadoff-Chu sequence, or by causing a phase cyclic shift value α to be different according to each component carrier by adding the component carrier number or the offset value for each component carrier.
18. The apparatus as claimed in claim 16 , wherein the reference signal generator generates the base sequences, which are different by causing a root value q of the Zadoff-Chu sequence or a sequence group number u constructing the root value q of the Zadoff-Chu sequence to have a difference by adding the component carrier number or the offset value for each component carrier.
19. An apparatus for receiving a reference signal in a wireless communication system using at least two component carriers, the apparatus comprising:
a reference signal receiver for receiving a reference signal, which is generated in such a manner as to be different according to each component carrier by using a reference signal sequence enabling discrimination for each component carrier and is transmitted, for each component carrier; and
a reference information extractor for decoding the reference signal received by the reference signal receiver and extracting particular reference information,
wherein from the reference signal, the reference signal receiver configures a base sequence based on a Zadoff-Chu sequence, performs phase cyclic shift on the constructed base sequence, and constructs a reference signal sequence r u,v (α) (n), and
the reference signal receiver identifies the reference signal enabling the discrimination for each component carrier generated by using the reference signal sequence, which is generated by generating the Zadoff-Chu sequence different according to each component carrier and constructing the different base sequences, or by causing a phase cyclic shift value α to be different according to each component carrier.
20. The apparatus as claimed in claim 19 , wherein the reference signal receiver identifies the reference signal enabling the discrimination for each component carrier generated by using a reference signal sequence, which is generated by constructing a base sequence different according to each component carrier by adding a component carrier number or an offset value for each component carrier based on the Zadoff-Chu sequence, or by causing a phase cyclic shift value α to be different according to each component carrier by adding the component carrier number or the offset value for each component carrier.
21. The apparatus as claimed in claim 20 , wherein the reference signal receiver identifies the reference signals generated by using the base sequences which are different by causing a root value q of the Zadoff-Chu sequence or a sequence group number u constructing the root value q of the Zadoff-Chu sequence to have a difference by adding the component carrier number or the offset value for each component carrier.