Method for scheduling distributed virtual resource blocks
View Patent ↗A method for efficiently scheduling virtual resource blocks to physical resource blocks is disclosed. In a wireless mobile communication system that supports a resource block group (RBG) allocation scheme, for distributed mapping of consecutively allocated virtual resource blocks to physical resource blocks, there is proposed a mapping method capable of increasing the number of distributed virtual resource blocks to a maximum while satisfying gap limitations, when the length of the physical resource blocks is different from the length of the distributed virtual resource blocks. Also, the number of distributed virtual resource blocks and the structure of an interleaver are limited for efficient scheduling.
1. A method for distributively mapping virtual resource blocks (VRBs) to physical resource blocks (PRBs) in a wireless mobile communication system, the method comprising:
interleaving by a base station, indexes of the VRBs, of a downlink data packet using a block interleaver;
mapping the interleaved indexes onto a first slot and a second slot of a subframe of a downlink data packet with a gap for distribution; and
transmitting the mapped data packet to a user equipment,
wherein an index o 1,d of one of the PRBs on the first slot mapped to a given index d of one of the VRBs is set to p 1,d +N offset if a temporary index p 1,d of one of the PRBs on the first slot mapped to the index d by the block interleaver is larger than N DVRB /2, and an index o 2,d of the one of the PRBs on the second slot mapped to the index d is set to p 2,d +N offset if a temporary index p 2,d of one of the PRBs on the second slot mapped to the index d by the block interleaver is larger than N DVRB /2,
wherein N DVRB is a number of the VRBs and N offset is a predetermined integer, and
wherein d has an integer value in a range from 0 to N DVRB −1, and p 1,d , p 2,d , o 1,d , and o 2,d have an integer value in a range from 0 to N PRB −1, N PRB being a number of the PRBs in the wireless mobile communication system, wherein the wireless mobile communication system supports a resource allocation scheme.
2. The method according to claim 1 , wherein N offset =N PRB −N DVRB .
3. The method according to claim 1 , wherein N offset =N gap −N DVRB /2.
4. The method according to claim 1 , wherein the temporary index P 1,d is given in expression (1), and the temporary index p 2,d is given in expression (2), wherein
expression
(
1
)
is
p
1
,
d
=
{
p
1
,
d
′
,
when
N
null
=
0
or
(
d
<
N
DVRB
-
N
null
and
mod
(
d
,
C
)
<
2
)
p
1
,
d
′
-
N
null
/
2
,
when
N
null
≠
0
and
(
d
<
N
DVRB
-
N
null
and
mod
(
d
,
C
)
≥
2
)
where
p
1
,
d
′
=
mod
(
d
,
C
)
·
R
+
⌊
d
/
C
⌋
p
1
,
d
=
{
p
1
,
d
′
-
R
+
N
null
/
2
,
when
N
null
≠
0
and
(
d
≥
N
DVRB
-
N
null
and
mod
(
d
,
C
/
2
)
=
0
)
p
1
,
d
′
-
R
,
when
N
null
≠
0
and
(
d
≥
N
DVRB
-
N
null
and
mod
(
d
,
C
/
2
)
=
1
)
where
p
1
,
d
′
=
mod
(
d
,
C
/
2
)
·
2
R
+
⌊
2
d
/
C
⌋
;
and
expression
(
2
)
is
p
2
,
d
=
mod
(
p
1
,
d
+
N
DVRB
/
2
,
N
DVRB
)
where R is a number of rows of the block interleaver, C is a number of columns of the block interleaver, N DVRB is a number of resource blocks used for the VRBs, and ‘mod’ means a modulo operation.
5. The method according to claim 1 , wherein the wireless mobile communication system supports a resource allocation scheme in which one resource block group (RBG) including consecutive PRBs is indicated by one bit, and wherein
the gap for the distribution is a multiple of a square of a number of the consecutive PRBs constituting the RBG.
6. The method according to claim 5 , wherein the gap for distribution is given in expression (1), wherein expression (1) is
N gap =round( N PRB /(2· M RBG 2 ))· M RBG 2
where M RBG is the number of the consecutive PRBs constituting the RBG and N gap is the gap for the distribution.
7. The method according to claim 1 , wherein a degree of the block interleaver is equal to a diversity order (N DivOrder ) determined by the distribution.
8. The method according to claim 1 , wherein the wireless mobile communication system supports a resource allocation scheme in which one resource block group (RBG) including consecutive PRBs is indicated by one bit, and
wherein the number of the VRBs (N DVRB ) is a multiple of a value obtained by multiplying a square of the number of the consecutive PRBs constituting the RBG (M RBG 2 ) by a number of the PRBs to which one VRB is mapped (N D ).
9. The method according to claim 1 , wherein the wireless mobile communication system supports a resource allocation scheme in which one resource block group (RBG) including consecutive PRBs is indicated by one bit, and
wherein a degree of the block interleaver is defined as a number of columns of the block interleaver (C=4), a number of rows of the block interleaver (R) is given as expression (1) and the number of nulls (N null ) filled in the block interleaver is given as expression (2), wherein
expression (1) is
R=N int erleaver /C=┌N DVRB /( C·M RBG )┐· M RBG
N int erleaver =┌N DVRB /( C·M RBG )┐· C·M RBG ; and
expression (2) is
N null =N int erleaver −N DVRB =┌N DVRB /( C·M RBG )┌· C·M RBG −N DVRB
N int erleaver =┌N DVRB /( C·M RBG )┐· C·M RBG
where M RBG is a number of the consecutive PRBs constituting the RBG and N DVRB is the number of the VRBs.
10. The method according to claim 9 , wherein the number of the VRBs (N DVRB ) is given as expression (3) when nulls are input to the block interleaver, wherein expression (3) is N DVRB =min(N PRB −N gap , N gap )·2.
11. The method according to claim 7 , wherein the diversity order (N DivOrder ) is an integer multiple of a number of PRBs to which one VRB is mapped (N D ).
12. The method according to claim 1 , further comprising receiving a resource indication value (RIV) at a mobile station of the wireless mobile communication system, wherein the RIV is used to determine the indexes of the VRBs and indicates a start index number of the VRBs and a length of the VRBs.
13. The method according to claim 1 , wherein the gap is 0 when N DVRB is larger than or equal to a predetermined threshold value (M th ).
14. The method according to claim 1 , wherein N DVRB is an integer multiple of a diversity order (N DivOrder ) determined by the distribution.