Method for mapping physical hybrid automatic repeat request indicator channel
View Patent ↗A method for mapping a physical hybrid automatic repeat request indicator channel (PHICH) is described. The method for mapping a PHICH includes determining an index of a resource element group transmitting a repetitive pattern of the PHICH, according to a ratio of the number of available resource element groups in a symbol in which the PHICH is transmitted and the number of available resource element groups in a first or second OFDM symbol, and mapping the PHICH to the symbol according to the determined index. In transmitting the PHICH, since efficient mapping is performed considering available resource elements varying with OFDM symbols, repetition of the PHICH does not generate interference between neighbor cell IDs and performance is improved.
1. A method of transmitting ACK/NACK (acknowledgement/negative acknowledgement) information through a physical hybrid automatic repeat request indicator channel (PHICH), the method comprising:
mapping the ACK/NACK information to resource elements of an orthogonal frequency division multiplexing (OFDM) symbol of index l′ i ,
wherein the resource elements of the OFDM symbol of index l′ i corresponds to a resource element group (REG) index ( n i ) that is defined by one of the following equations:
n
_
i
=
{
(
⌊
(
N
ID
cell
·
n
l
i
′
′
/
n
0
′
)
⌋
+
m
′
)
mod
n
l
i
′
′
i
=
0
(
⌊
(
N
ID
cell
·
n
l
i
′
′
/
n
0
′
)
⌋
+
m
′
+
⌊
n
l
i
′
′
/
3
⌋
)
mod
n
l
i
′
′
i
=
1
(
⌊
(
N
ID
cell
·
n
l
i
′
′
/
n
0
′
)
⌋
+
m
′
+
⌊
2
n
l
i
′
′
/
3
⌋
)
mod
n
l
i
′
′
i
=
2
equation
1
where N ID cell denotes a cell ID, n′ l′ i denotes a number of available REGs in the OFDM symbol of index l′ i , n′ 0 denotes a number of available REGs in an OFDM symbol of index 0, and m′ denotes an index related to a PHICH group in which the PHICH is included, and
n
_
i
=
{
(
⌊
(
N
ID
cell
·
n
l
i
′
′
/
n
1
′
)
⌋
+
m
′
)
mod
n
l
i
′
′
i
=
0
(
⌊
(
N
ID
cell
·
n
l
i
′
′
/
n
1
′
)
⌋
+
m
′
+
⌊
n
l
i
′
′
/
3
⌋
)
mod
n
l
i
′
′
i
=
1
(
⌊
(
N
ID
cell
·
n
l
i
′
′
/
n
1
′
)
⌋
+
m
′
+
⌊
2
n
l
i
′
′
/
3
⌋
)
mod
n
l
i
′
′
i
=
2
equation
2
where n ID cell denotes a cell ID, n′ l′ i denotes the number of available REGs in the OFDM symbol of index l′ i , n′ 1 denotes a number of available REGs in an OFDM symbol of index 1, and m′ denotes the index related to a PHICH group in which the PHICH is included.
2. The method of claim 1 , wherein the index l′ i is defined by the following equation:
l
i
′
=
{
0
normal
PHICH
duration
,
all
subframes
i
extended
PHICH
duration
,
non
-
MBSFN
subframes
(
⌊
m
′
/
2
⌋
+
i
+
1
)
mod
2
extended
PHICH
duration
,
MBSFN
subframes
where m′ denotes the index related to the PHICH group in which the PHICH is included.
3. The method of claim 1 , wherein the ACK/NACK information includes spread ACK/NACK information.
4. The method of claim 1 , wherein the number of available REGs in an OFDM symbol is defined as a number of REGs not assigned to physical control format indicator channel (PCFICH) in the OFDM symbol.
5. The method of claim 1 , wherein resource elements corresponding to each REG index consist of four resource elements.
6. The method of claim 1 , wherein the PHICH is transmitted using two or four resource elements among the resource elements corresponding to each REG index.
7. The method of claim 1 , wherein the ACK/NACK information is transmitted via multi-antennas.
8. A method of transmitting an ACK/NACK (acknowledgement/negative acknowledgement) signal by a transmitting end in a wireless communication system, the method comprising:
spreading ACK/NACK information using a plurality of spreading codes, wherein the plurality of spreading codes have a spreading factor (SF) of 4;
multiplexing the spread ACK/NACK information by code division multiplexing to generate ACK/NACK signal corresponding to a physical hybrid ARQ indicator channel (PHICH) group; and
transmitting, to a receiving end, the ACK/NACK signal using resource elements corresponding to resource element group (REG) indexes ( n i ),
wherein the REG indexes ( n i ) are defined by the following equation:
n
_
i
=
{
(
⌊
(
N
ID
cell
·
n
l
i
′
′
/
n
0
′
)
⌋
+
m
′
)
mod
n
l
i
′
′
i
=
0
(
⌊
(
N
ID
cell
·
n
l
i
′
′
/
n
0
′
)
⌋
+
m
′
+
⌊
n
l
i
′
′
/
3
⌋
)
mod
n
l
i
′
′
i
=
1
(
⌊
(
N
ID
cell
·
n
l
i
′
′
/
n
0
′
)
⌋
+
m
′
+
⌊
2
n
l
i
′
′
/
3
⌋
)
mod
n
l
i
′
′
i
=
2
where N ID cell denotes a cell ID, n′ l i ′ denotes a number of available REGs in the OFDM symbol of index l′ i within a subframe, n′ 0 denotes a number of available REGs in an OFDM symbol of index 0 within the subframe, and m′ denotes an index related to the PHICH group.
9. The method of claim 8 , wherein the index l′ i is defined by the following equation:
l
i
′
=
{
0
normal
PHICH
duration
,
all
subframes
i
extended
PHICH
duration
,
non
-
MBSFN
subframes
(
⌊
m
′
/
2
⌋
+
i
+
1
)
mod
2
extended
PHICH
duration
,
MBSFN
subframes
where m′ denotes the index related to the PHICH group.
10. The method of claim 8 , wherein the number of available REGs in an OFDM symbol is defined as a number of REGs not assigned to physical control format indicator channel (PCFICH) in the OFDM symbol.
11. The method of claim 8 , wherein resource elements corresponding to each REG index consist of four resource elements.
12. A method of transmitting an ACK/NACK (acknowledgement/negative acknowledgement) signal by a transmitting end in a wireless communication system, the method comprising:
spreading ACK/NACK information using a plurality of spreading codes, wherein the plurality of spreading codes have a spreading factor (SF) of 2;
multiplexing the spread ACK/NACK information by code division multiplexing to generate a plurality of ACK/NACK signals corresponding to a plurality of physical hybrid ARQ indicator channel (PHICH) group; and
transmitting, to a receiving end, two ACK/NACK signals corresponding to two consecutive PHICH groups together using resource elements corresponding to resource element group (REG) indexes ( n i ),
wherein the REG indexes ( n i ) are defined by the following equation:
n
_
i
=
{
(
⌊
(
N
ID
cell
·
n
l
i
′
′
/
n
1
′
)
⌋
+
m
′
)
mod
n
l
i
′
′
i
=
0
(
⌊
(
N
ID
cell
·
n
l
i
′
′
/
n
1
′
)
⌋
+
m
′
+
⌊
n
l
i
′
′
/
3
⌋
)
mod
n
l
i
′
′
i
=
1
(
⌊
(
N
ID
cell
·
n
l
i
′
′
/
n
1
′
)
⌋
+
m
′
+
⌊
2
n
l
i
′
′
/
3
⌋
)
mod
n
l
i
′
′
i
=
2
where N ID cell denotes a cell ID, n l i ′ ′ denotes a number of available REGs in the OFDM symbol of index l i ′ within a subframe, n 1 ′ denotes a number of available REGs in an OFDM symbol of index 1 within the subframe, and m′ denotes an index related to the two consecutive PHICH groups.
13. The method of claim 12 , wherein the index l′ i is defined by the following equation:
l
i
′
=
{
0
normal
PHICH
duration
,
all
subframes
i
extended
PHICH
duration
,
non
-
MBSFN
subframes
(
⌊
m
′
/
2
⌋
+
i
+
1
)
mod
2
extended
PHICH
duration
,
MBSFN
subframes
where m′ denotes the index related to the two consecutive PHICH groups.
14. The method of claim 12 , wherein the number of available REGs in an OFDM symbol is defined as a number of REGs not assigned to a physical control format indicator channel (PCFICH) in the OFDM symbol.
15. The method of claim 12 , wherein resource elements corresponding to each REG index consist of four resource elements.
16. A method of receiving an ACK/NACK (acknowledgement/negative acknowledgement) signal through a physical hybrid automatic repeat request indicator channel (PHICH) from a transmitting end, the method comprising:
receiving orthogonal frequency division multiplexing (OFDM) symbols from the transmitting end, wherein the OFDM symbols include resource elements,
wherein the ACK/NAK signal is received through resource elements corresponding to resource element group (REG) indexes ( n i ), and
wherein the REG indexes ( n i ) are defined by one of the following equations:
n
_
i
=
{
(
⌊
(
N
ID
cell
·
n
l
i
′
′
/
n
0
′
)
⌋
+
m
′
)
mod
n
l
i
′
′
i
=
0
(
⌊
(
N
ID
cell
·
n
l
i
′
′
/
n
0
′
)
⌋
+
m
′
+
⌊
n
l
i
′
′
/
3
⌋
)
mod
n
l
i
′
′
i
=
1
(
⌊
(
N
ID
cell
·
n
l
i
′
′
/
n
0
′
)
⌋
+
m
′
+
⌊
2
n
l
i
′
′
/
3
⌋
)
mod
n
l
i
′
′
i
=
2
equation
1
where N ID cell denotes a cell ID, n′ l′ i denotes a number of available REGs in the OFDM symbol of index l′ i , n′ 0 denotes a number of available REGs in an OFDM symbol of index 0, and m′ denotes an index related to a PHICH group in which the PHICH is included, and
n
_
i
=
{
(
⌊
(
N
ID
cell
·
n
l
i
′
′
/
n
1
′
)
⌋
+
m
′
)
mod
n
l
i
′
′
i
=
0
(
⌊
(
N
ID
cell
·
n
l
i
′
′
/
n
1
′
)
⌋
+
m
′
+
⌊
n
l
i
′
′
/
3
⌋
)
mod
n
l
i
′
′
i
=
1
(
⌊
(
N
ID
cell
·
n
l
i
′
′
/
n
1
′
)
⌋
+
m
′
+
⌊
2
n
l
i
′
′
/
3
⌋
)
mod
n
l
i
′
′
i
=
2
equation
2
where N ID cell denotes a cell ID, n′ l′ i denotes the number of available REGs in the OFDM symbol of index, l′ i , n′ 1 denotes a number of available REGs in an OFDM symbol of index 1, and m′ denotes the index related to a PHICH group in which the PHICH is included.
17. The method of claim 16 , wherein the index l′ i is defined by the following equation:
l
i
′
=
{
0
normal
PHICH
duration
,
all
subframes
i
extended
PHICH
duration
,
non
-
MBSFN
subframes
(
⌊
m
′
/
2
⌋
+
i
+
1
)
mod
2
extended
PHICH
duration
,
MBSFN
subframes
where m′ denotes the index related to a PHICH group in which the PHICH is included.
18. The method of claim 16 , wherein the ACK/NACK signal includes spread ACK/NACK information.
19. The method of claim 16 , wherein the number of available REGs in an OFDM symbol is defined as a number of REGs not assigned to physical control format indicator channel (PCFICH) in the OFDM symbol.
20. The method of claim 16 , wherein resource elements corresponding to each REG index consist of four resource elements.
21. The method of claim 16 , wherein the ACK/NAK signal is received using two or four resource elements among the resource elements corresponding to each REG index.
22. The method of claim 16 , wherein the ACK/NACK signal is transmitted from the transmitting end via multi-antennas.
23. An apparatus of transmitting ACK/NACK (acknowledgement/negative acknowledgement) information through a physical hybrid automatic repeat request indicator channel (PHICH), the apparatus configured to:
map the ACK/NACK information to resource elements of an orthogonal frequency division multiplexing (OFDM) symbol of index l′ i ,
wherein the resource elements of the OFDM symbol of index l′ i corresponds to an REG index ( n i ) that is defined by one of the following equations:
n
_
i
=
{
(
⌊
(
N
ID
cell
·
n
l
i
′
′
/
n
0
′
)
⌋
+
m
′
)
mod
n
l
i
′
′
i
=
0
(
⌊
(
N
ID
cell
·
n
l
0
′
′
/
n
0
′
)
⌋
+
m
′
+
⌊
n
l
i
′
′
/
3
⌋
)
mod
n
l
i
′
′
i
=
1
(
⌊
(
N
ID
cell
·
n
l
i
′
′
/
n
0
′
)
⌋
+
m
′
+
⌊
2
n
l
i
′
′
/
3
⌋
)
mod
n
l
i
′
′
i
=
2
equation
1
where N ID cell denotes a cell ID, n′ l′ i denotes a number of available REGs in the OFDM symbol of index l′ i , n′ 0 denotes a number of available REGs in an OFDM symbol of index 0, and m′ denotes an index related with a PHICH group in which the PHICH is included, and
n
_
i
=
{
(
⌊
(
N
ID
cell
·
n
l
i
′
′
/
n
1
′
)
⌋
+
m
′
)
mod
n
l
i
′
′
i
=
0
(
⌊
(
N
ID
cell
·
n
l
i
′
′
/
n
1
′
)
⌋
+
m
′
+
⌊
n
l
i
′
′
/
3
⌋
)
mod
n
l
i
′
′
i
=
1
(
⌊
(
N
ID
cell
·
n
l
i
′
′
/
n
1
′
)
⌋
+
m
′
+
⌊
2
n
l
i
′
′
/
3
⌋
)
mod
n
l
i
′
′
i
=
2
equation
2
where N ID cell denotes the cell ID, n′ l′ i denotes the number of available REGs in the OFDM symbol of index l′ i , n′ 1 denotes a number of available REGs in an OFDM symbol of index 1, and m′ denotes an index related with a PHICH group in which the PHICH is included.
24. An apparatus of receiving ACK/NACK (acknowledgement/negative acknowledgement) signal through a physical hybrid automatic repeat request indicator channel (PHICH) from a transmitting end, the apparatus configured to:
receive orthogonal frequency division multiplexing (OFDM) symbols from the transmitting end, wherein the OFDM symbols include resource elements,
wherein the ACK/NACK signal is received through resource elements corresponding to resource element group (REG) indexes ( n i ), and
wherein the REG indexes ( n i ) is defined by one of the following equations:
n
_
i
=
{
(
⌊
(
N
ID
cell
·
n
l
i
′
′
/
n
0
′
)
⌋
+
m
′
)
mod
n
l
i
′
′
i
=
0
(
⌊
(
N
ID
cell
·
n
l
i
′
′
/
n
0
′
)
⌋
+
m
′
+
⌊
n
l
i
′
′
/
3
⌋
)
mod
n
l
i
′
′
i
=
1
(
⌊
(
N
ID
cell
·
n
l
i
′
′
/
n
0
′
)
⌋
+
m
′
+
⌊
2
n
l
i
′
′
/
3
⌋
)
mod
n
l
i
′
′
i
=
2
equation
1
where N ID cell denotes a cell ID, n′ l′ i denotes a number of available REGs in the OFDM symbol of index l′ i , n′ 0 denotes a number of available REGs in an OFDM symbol of index 0, and m′ denotes an index related with a PHICH group in which the PHICH is included, and
n
_
i
=
{
(
⌊
(
N
ID
cell
·
n
l
i
′
′
/
n
1
′
)
⌋
+
m
′
)
mod
n
l
i
′
′
i
=
0
(
⌊
(
N
ID
cell
·
n
l
i
′
′
/
n
1
′
)
⌋
+
m
′
+
⌊
n
l
i
′
′
/
3
⌋
)
mod
n
l
i
′
′
i
=
1
(
⌊
(
N
ID
cell
·
n
l
i
′
′
/
n
1
′
)
⌋
+
m
′
+
⌊
2
n
l
i
′
′
/
3
⌋
)
mod
n
l
i
′
′
i
=
2
equation
2
where N ID cell denotes the cell ID, n′ l′ i denotes the number of available REGs in the OFDM symbol of index l′ i , n′ 1 denotes a number of available REGs in an OFDM symbol of index 1, and m′ denotes an index related with a PHICH group in which the PHICH is included.