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 for transmitting a signal comprising acknowledgement/negative acknowledgement (ACK/NACK) mapped in an orthogonal frequency division multiplexing (OFDM) symbol, the method comprising:
determining, at a processor, a frequency domain index of i-th resource element group (REG) in which the ACK/NACK is mapped, wherein the number i is an integer of 0 to 2, the i-th REG is comprised in an OFDM symbol having symbol index l′ i , the frequency domain index of the i-th REG is determined based on a ratio of a number of available resource element groups (REGs) in the OFDM symbol having symbol index l′ i to a number of available REGs in an OFDM symbol having symbol index 0 or 1, and available REGs are REGs not assigned to Physical Control Format Indicator Channel (PCFICH);
mapping the ACK/NACK to the i-th REG according to the determined frequency domain index; and
transmitting, at a wireless transceiver, the signal comprising the mapped ACK/NACK.
2. The method of claim 1 , wherein the symbol index l′ i =0 if the ACK/NACK is transmitted through one OFDM symbol.
3. The method of claim 2 , wherein the number of available REGs in the OFDM symbol having symbol index l′ i serves as a divisor of a modulo operation in the determination of the frequency domain index of the i-th REG.
4. The method of claim 3 , wherein the number of available REGs in the OFDM symbol having symbol index l′ i serves as an offset parameter in the determination of the frequency domain index of the i-th REG for i=1 and 2.
5. The method of claim 2 , wherein the symbol index l′ i =(└m′/2┘+i+1)mod 2 if the ACK/NACK is transmitted through two OFDM symbols, and the symbol index l′ i =i if the ACK/NACK is transmitted through three OFDM symbols,
where m′ denotes an index related to Physical Hybrid Automatic Repeat reQuest (HARD) Indicator Channel (PHICH) group in which the ACK/NACK is included.
6. The method of claim 1 , wherein the frequency domain index ( n i ) of the i-th REG to which the ACK/NACK is mapped is determined using 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 identifier (ID), n′ l′ i /n′ 0 denotes the ratio of the number of available REGs in the OFDM symbol having symbol index l′ i to the number of available REGs in the OFDM symbol having symbol index 0,
or
=
{
(
⌊
(
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 identifier (ID), n′ l′ i /n′ 1 denotes the ratio of the number of available REGs in the OFDM symbol having symbol index l′ i to the number of available REGs in the OFDM symbol having symbol index 1.
7. A method for transmitting a signal comprising acknowledgement/negative acknowledgement (ACK/NACK) mapped in an orthogonal frequency division multiplexing (OFDM) symbol, the method comprising:
determining, at a processor, a frequency domain index of i-th resource element group (REG) in which the ACK/NACK is mapped, wherein the number i is an integer of 0 to 2, the i-th REG is comprised in an OFDM symbol having symbol index l′ i , the frequency domain index of the i-th REG is determined based on a number of available resource element groups (REGs) in the OFDM symbol having symbol index l′ i , and available REGs are REGs not assigned to Physical Control Format Indicator Channel (PCFICH);
mapping the ACK/NACK to the i-th REG according to the determined frequency domain index; and
transmitting, at a wireless transceiver, the signal comprising the mapped ACK/NACK.
8. The method of claim 7 , wherein the symbol index l′ i =0 if the ACK/NACK is transmitted through one OFDM symbol.
9. The method of claim 8 , wherein the symbol index l′ i =(└m′/2┘+i+1)mod 2 if the ACK/NACK is transmitted through two OFDM symbols, and the symbol index l′ i =i if the ACK/NACK is transmitted through three OFDM symbols,
where m′ denotes an index related to Physical Hybrid Automatic Repeat reQuest (HARQ) Indicator Channel (PHICH) group in which the ACK/NACK is included.
10. The method of claim 8 , wherein the number of available REGs in the OFDM symbol having symbol index l′ i serves as a divisor of a modulo operation in the determination of the frequency domain index of the i-th REG.
11. The method of claim 10 , wherein a parameter determined based on a cell identifier (ID) and the m′ serves as a dividend of the modulo operation in the determination of the frequency domain index of the i-th REG.
12. The method of claim 11 , wherein └n′ l′ i /3┘ the number of available REGs in the OFDM symbol having symbol index l′ i serves as an offset parameter in the determination of the frequency domain index of the i-th REG for i=1 and 2.
13. The method of claim 12 , wherein └n′ l′ i /3┘ serves as a first offset in the determination of the frequency domain index of the i-th REG for i=1, and
└2n′ l′ i /3┘ serves as a second offset in the determination of the frequency domain index of the i-th REG for i=2.
14. The method of claim 7 , wherein the frequency domain index of the i-th REG for i=0 and 2 is determined based on a ratio of a number of available resource element groups (REGs) in the OFDM symbol having symbol index l′ i to a number of available REGs in an OFDM symbol having symbol index 0.
15. The method of claim 7 , wherein the frequency domain index of the i-th REG for i=1 is determined based on a ratio of a number of available resource element groups (REGs) in the OFDM symbol having symbol index l′ i to a number of available REGs in an OFDM symbol having symbol index 1.
16. The method of claim 7 , wherein the frequency domain index ( n i ) of the i-th REG to which the ACK/NACK is mapped is determined using 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 identifier (ID), n′ l′ i /n′ 0 denotes the ratio of the number of available REGs in the OFDM symbol having symbol index l′ i to the number of available REGs in the OFDM symbol having symbol index 0,
or
=
{
(
⌊
(
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 identifier (ID), n′ l′ i /n′ 1 denotes the ratio of the number of available REGs in the OFDM symbol having symbol index l′ i to the number of available REGs in the OFDM symbol having symbol index 1.
17. An apparatus to transmit a signal comprising acknowledgement/negative acknowledgement (ACK/NACK) mapped in an orthogonal frequency division multiplexing (OFDM) symbol, the apparatus comprising:
a processor configured to determine a frequency domain index of i-th resource element group (REG) in which the ACK/NACK is mapped, wherein the number i is an integer of 0 to 2, the i-th REG is comprised in an OFDM symbol having symbol index l′ i , the frequency domain index of the i-th REG is determined based on a ratio of a number of available resource element groups (REGs) in the OFDM symbol having symbol index l′ i to a number of available REGs in an OFDM symbol having symbol index 0 or 1, and to map the ACK/NACK to the i-th REG according to the determined frequency domain index of the i-th REG; and
a transmitter to transmit the signal comprising the mapped ACK/NACK,
wherein available REGs are REGs not assigned to Physical Control Format Indicator Channel (PCFICH).
18. The apparatus of claim 17 , wherein the symbol index l′ i =0 if the ACK/NACK is transmitted through one OFDM symbol.
19. The apparatus of claim 18 , wherein the number of available REGs in the OFDM symbol having symbol index l′ i serves as a divisor of a modulo operation in the determination of the frequency domain index of the i-th REG.
20. The apparatus of claim 19 , wherein the number of available REGs in the OFDM symbol having symbol index l′ i serves as an offset parameter in the determination of the frequency domain index of the i-th REG for i=1 and 2.
21. The apparatus of claim 18 , wherein the symbol index l′ i =(└m′/2┘+i+1)mod 2 if the ACK/NACK is transmitted through two OFDM symbols, and the symbol index l′ i =i if the ACK/NACK is transmitted through three OFDM symbols,
where m′ denotes an index related to Physical Hybrid Automatic Repeat reQuest (HARM) Indicator Channel (PHICH) group in which the ACK/NACK is included.
22. The apparatus of claim 17 , wherein the frequency domain index ( n i ) of the i-th REG to which the ACK/NACK is mapped is determined using 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 a cell identifier (ID), n′ l′ i /n′ 0 denotes the ratio of the number of available REGs in the OFDM symbol having symbol index l′ i to the number of available REGs in the OFDM symbol having symbol index 0,
or
=
{
(
⌊
(
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 identifier (ID), n′ l′ i /n′ 1 denotes the ratio of the number of available REGs in the OFDM symbol having symbol index l′ i to the number of available REGs in the OFDM symbol having symbol index 1.
23. An apparatus to transmit acknowledgement/negative acknowledgement (ACK/NACK) mapped in an orthogonal frequency division multiplexing (OFDM) symbol, the apparatus comprising:
a processor configured to determine a frequency domain index of i-th resource element group (REG) in which the ACK/NACK is mapped, wherein the number i is an integer of 0 to 2, the i-th REG is comprised in an OFDM symbol having symbol index l′ i , the frequency domain index of the i-th REG is determined based on a number of available resource element groups (REGs) in the OFDM symbol having symbol index l′ i , and to map the ACK/NACK to the i-th REG according to the determined frequency domain index of the i-th REG; and
a transmitter to transmit a signal comprising the mapped ACK/NACK;
wherein available REGs are REGs not assigned to Physical Control Format Indicator Channel (PCFICH).
24. The apparatus of claim 23 , wherein the symbol index l′ i =0 if the ACK/NACK is transmitted through one OFDM symbol.
25. The apparatus of claim 24 , wherein the symbol index l′ i =(└m′/2┘+i+1)mod 2 if the ACK/NACK is transmitted through two OFDM symbols, and the symbol index l′ i =i if the ACK/NACK is transmitted through three OFDM symbols,
where m′ denotes an index related to Physical Hybrid Automatic Repeat reQuest (HARD) Indicator Channel (PHICH) group in which the ACK/NACK is included.
26. The apparatus of claim 24 , wherein the number of available REGs in the OFDM symbol having symbol index l′ i serves as a divisor of a modulo operation in the determination of the frequency domain index of the i-th REG.
27. The apparatus of claim 26 , wherein a parameter determined based on a cell identifier (ID) and the m′ serves as a dividend of the modulo operation in the determination of the frequency domain index of the i-th REG.
28. The apparatus of claim 27 , wherein the number of available REGs in the OFDM symbol having symbol index l′ i serves as an offset parameter in the determination of the frequency domain index of the i-th REG for i=1 and 2.
29. The apparatus of claim 28 , wherein └n′ l′ i /3┘ serves as a first offset in the determination of the frequency domain index of the i-th REG for i=1, and
└2n′ l′ i /3┘ serves as a second offset in the determination of the frequency domain index of the i-th REG for i=2.
30. The apparatus of claim 23 , wherein the frequency domain index of the i-th REG for i=0 and 2 is determined based on a ratio of a number of available resource element groups (REGs) in the OFDM symbol having symbol index l′ i to a number of available REGs in an OFDM symbol having symbol index 0.
31. The apparatus of claim 23 , wherein the frequency domain index of the i-th REG for i=1 is determined based on a ratio of a number of available resource element groups (REGs) in the OFDM symbol having symbol index l′ i to a number of available REGs in an OFDM symbol having symbol index 1.
32. The apparatus of claim 23 , wherein the frequency domain index ( n i ) of the i-th REG to which the ACK/NACK is mapped is determined using 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 identifier (ID), n′ l′ i /n′ 0 denotes the ratio of the number of available REGs in the OFDM symbol having symbol index l′ i to the number of available REGs in the OFDM symbol having symbol index 0,
or
=
{
(
⌊
(
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 identifier (ID), n′ l′ i /n′ 1 denotes the ratio of the number of available REGs in the OFDM symbol having symbol index l′ i to the number of available REGs in the OFDM symbol having symbol index 1.