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 transmitting downlink data using resource blocks at a base station in a wireless mobile communication system, the method comprising:
transmitting downlink data mapped to physical resource blocks (PRBs) to a user equipment,
wherein:
indexes of virtual resource blocks (VRBs) are mapped to indexes of the PRBs for each of N s slots of a subframe, N s denoting a number of slots included in the subframe,
indexes of the PRBs for an odd-numbered slot are shifted with respect to indexes of the PRBs for an even-numbered slot based on a predetermined gap, and
an index of one of the PRBs on each of the N s slots that are mapped to an index of one of the VRBs is determined by using N gap and N DVRB
where N gap is a value of the predetermined gap and N DVRB is a number of the VRBs.
2. The method according to claim 1 , wherein:
the indexes of the VRBs are interleaved by a block interleaver,
an index o 1,d of one of the PRBs on the odd-numbered slot of N s slots that is mapped to a given index d of one of the VRBs is set to p 1,d +N gap −N DVRB /2 if a temporary index p 1,d of one of the PRBs on the odd-numbered slot that is mapped to the index d by the block interleaver is greater than or equal to N DVRB /2,
an index o 2,d of the one of the PRBs on the even-numbered slot of N s slots that is mapped to the index d is set to p 2,d +N gap −N DVRB /2 if a temporary index p 2,d of one of the PRBs on the even-numbered slot that is mapped to the index d by the block interleaver is greater than or equal to N DVRB /2, and
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.
3. The method according to claim 2 , 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.
4. The method according to claim 2 ,
wherein:
a number of rows of the block interleaver (R) is given as expression (1) and a number of nulls (N null ) filled in the block interleaver is given as expression (2), wherein
expression (1) is
R=N interleaver /C=┌N DVRB /( C·M RBG )┐· M RBG
N interleaver =┌N DVRB /( C·M RBG )┐· C·M RBG , and
expression (2) is
N null =N interleaver −N DVRB =┌N DVRB /( C·M RBG )┐· C·M RBG −N DVRB
where C is a number of columns of the block interleaver and M RBG is a number of consecutive PRBs constituting one resource block group (RBG).
5. The method according to claim 4 , wherein the number of the VRBs (N DVRB ) is given as expression (3) where expression (3) is N DVRB =min(N PRB −N gap , N gap )·2.
6. A method for receiving downlink data using resource blocks at a user equipment in a wireless mobile communication system, the method comprising:
receiving downlink control information including resource allocation information for the downlink data from a base station; and
receiving the downlink data mapped to physical resource blocks (PRBs) based on the downlink control information,
wherein:
the resource allocation information indicates virtual resource block (VRB) allocations for the user equipment,
indexes of the PRBs to which the downlink data are mapped are determined based on a mapping relationship between virtual resource blocks (VRBs) and the PRBs,
the mapping relationship is defined as indexes of the VRBs that are mapped to the indexes of the PRBs for N s slots of a subframe, N s denoting a number of slots included in the subframe,
indexes of the PRBs for an odd-numbered slot are shifted with respect to indexes of the PRBs for an even-numbered slot based on a predetermined gap, and
an index of one of the PRBs on each of the N s slots that is mapped to an index of one of the VRBs is determined by using N gap and N DVRB where N gap is a value of the predetermined gap and N DVRB is a number of the VRBs.
7. The method according to claim 6 , wherein:
the indexes of the VRBs are interleaved by a block interleaver,
an index o 1,d of one of the PRBs on the odd-numbered slot of N s slots that is mapped to a given index d of one of the VRBs is set to p 1,d +N gap −N DVRB /2 if a temporary index p 1,d of one of the PRBs on the odd-numbered slot that is mapped to the index d by the block interleaver is greater than or equal to N DVRB /2,
an index o 2,d of the one of the PRBs on the even-numbered slot of N s slots that is mapped to the index d is set to p 2,d +N gap −N DVRB /2 if a temporary index p 2,d of one of the PRBs on the even-numbered slot that is mapped to the index d by the block interleaver is greater than or equal to N DVRB /2, and
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.
8. The method according to claim 7 , wherein the temporary index p 1,d is given in expression (1), and the temporary index p 2,d is given in expression (2), where
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.
9. The method according to claim 7 , wherein 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), where
expression (1) is
R=N interleaver /C=┌N DVRB /( C·M RBG )┐· M RBG
N interleaver =┌N DVRB /( C·M RBG )┐· C·M RBG ; and
expression (2) is
N null =N interleaver −N DVRB =┌N DVRB /( C·M RBG )┐· C·M RBG −N DVRB
where C is a number of columns of the block interleaver and M RBG is a number of consecutive PRBs constituting the RBG.
10. The method according to claim 9 , wherein the number of the VRBs (N DVRB ) is given as expression (3) where expression (3) is N DVRB =min(N PRB −N gap , N gap )·2.
11. A base station transmitting downlink data using resource blocks in a wireless mobile communication system, the base station comprising:
a processor configured to control an operation of the base station; and
a memory unit driven by the processor,
wherein:
the processor is configured to transmit downlink data mapped to physical resource blocks (PRBs) to a user equipment,
indexes of virtual resource blocks (VRBs) are mapped to indexes of the PRBs for N s slots of a subframe, the N s denoting a number of slots included in the subframe
indexes of the PRBs for an odd-numbered slot are shifted with respect to indexes of the PRBs for an even-numbered slot based on a predetermined gap,
an index of one of the PRBs on each of the N s slots that is mapped to an index of one of the VRBs is determined by using N gap and N DVRB where N gap is a value of the predetermined gap and N DVRB is a number of the VRBs.
12. A user equipment receiving downlink data using resource blocks in a wireless mobile communication system, the user equipment comprising:
a processor configured to control an operation of the user equipment; and
a memory unit driven by the processor,
wherein:
the processor is configured to:
receive downlink control information including resource allocation information for the downlink data from a base station; and
receive the downlink data mapped to physical resource blocks (PRBs) based on the downlink control information,
the resource allocation information indicates virtual resource block (VRB) allocations for the user equipment,
indexes of the PRBs to which the downlink data are mapped are determined based on a mapping relationship between virtual resource blocks (VRBs) and the PRBs,
the mapping relationship is defined as indexes of the VRBs that are mapped to the indexes of the PRBs for N s slots of a subframe, N s denoting a number of slots included in the subframe,
indexes of the PRBs for an odd-numbered slot are shifted with respect to indexes of the PRBs for an even-numbered slot based on a predetermined gap, and
an index of one of the PRBs on each of the N s slots that is mapped to an index of one of the VRBs is determined by using N gap and N DVRB where N gap is a value of the predetermined gap and N DVRB is a number of the VRBs.