Corrections to limited buffer rate-matching restriction
Embodiments include methods, performed by a user equipment (UE), for receiving downlink (DL) data from a serving cell in a wireless network. Such methods include determining whether a total number of coded bits for all transport blocks (TBs) scheduled for the UE, by the wireless network in the serving cell during a plurality of consecutive symbols, is greater than a limited-buffer rate-matching (LBRM) threshold. The LBRM threshold is based on a maximum number of transmission layers, X, associated with the UE for the serving cell. Such methods also include receiving and decoding a plurality of TBs, comprising one or more DL data messages, when the total number of coded bits for all TBs (including the plurality of TBs) scheduled for the UE is not greater than the LBRM threshold. Other embodiments include complementary methods performed by network nodes, and UEs and network nodes configured to perform such methods.
1. A method performed by a user equipment (UE) for receiving a physical downlink shared channel (PDSCH) transmission from a serving cell in a wireless network, the method comprising:
receiving a PDSCH transmission from the serving cell on an active bandwidth part (BWP);
decoding a plurality of transport blocks (TBs) partially or fully contained within a duration of a plurality of consecutive symbols ending at a last symbol of the PDSCH transmission, when a limited-buffer rate-matching (LBRM) condition is not satisfied, wherein the LBRM condition is:
2
max
(
0
,
μ
-
μ
′
)
.
∑
i
∈
S
⌊
C
i
′
L
i
⌋
x
i
.
F
i
>
ceil
(
X
4
)
.
1
R
L
B
R
M
.
T
B
S
L
B
R
M
where: R LBRM =2/3, TBS LBRM is an LBRM transport block size and X is a maximum number of transmission layers associated with the UE for the serving cell;
S is a set of all TBs scheduled for the UE on physical downlink shared channels (PDSCHs) that are at least partially included in the plurality of consecutive symbols, and i is an index to an i-th TB within S;
C i ′ is a number of scheduled code blocks for the i-th TB;
L i is a number of orthogonal frequency-division multiplexing (OFDM) symbols assigned to the PDSCH for the i-th TB;
x i is a number of OFDM symbols of the PDSCH that are included in the plurality of consecutive symbols;
F
i
=
max
j
=
0
,
…
,
J
-
1
(
min
(
k
0
,
i
j
+
E
i
j
,
N
c
b
,
i
)
)
,
where k 0,i j is the starting location of a redundancy version (RV) for the jth transmission, E i j =min(E r ) of the scheduled code blocks for the jth transmission, where E r is a rate matching output sequence length for the r-th coded block, N cb,i is a circular buffer length;
μ corresponds to a subcarrier spacing of an active bandwidth part (BWP); and
μ′ corresponds to the subcarrier spacing of a configured BWP having the largest number of configured physical resource blocks; and
wherein X is greater than four.
2. The method of claim 1 , wherein decoding the plurality of TBs comprises:
receiving a first TB via one or more first transmission layers;
receiving a second TB via one or more second transmission layers; and
decoding the respective first and second TBs.
3. The method of claim 1 , further comprising refraining from decoding the plurality of TBs when the LBRM condition is satisfied.
4. The method of claim 1 , wherein the plurality of TBs are received and decoded based on R LBRM and TBS LBRM .
5. The method of claim 1 , wherein the plurality of TBs constitute all TBs scheduled for the UE by the wireless network in the serving cell during the plurality of consecutive symbols.
6. The method of claim 1 , wherein X is given by:
a higher-layer parameter maxMIMO-Layers of the serving cell, when the higher-layer parameter has been configured for the UE by the wireless network; and
the maximum number of layers for physical downlink shared channel (PDSCH) supported by the UE for the serving cell, when the higher-layer parameter has not been configured for the UE by the wireless network.
7. The method of claim 1 , wherein the plurality of consecutive symbols is 14 consecutive symbols for normal cyclic prefix (CP) and 12 consecutive symbols for extended CP.
8. The method of claim 1 , further comprising determining that the LBRM condition is not satisfied for the duration of the plurality of consecutive symbols ending at the last symbol of the PDSCH transmission.
9. The method of claim 1 , wherein
2
max
(
0
,
μ
-
μ
′
)
.
∑
i
∈
S
⌊
C
i
′
L
i
⌋
x
i
.
F
i
is greater than
1
R
LMRM
.
T
B
S
L
B
R
M
10. The method of claim 1 , further comprising determining that the LBRM condition is satisfied for the duration of the plurality of consecutive symbols ending at the last symbol of the PDSCH transmission.
11. The method of claim 10 , comprising refraining from decoding the plurality of TBs when it is determined that the LBRM condition is satisfied.
12. A method performed by a network node for a serving cell in a wireless network for transmitting a physical downlink shared channel (PDSCH) transmission to a user equipment (UE), the method comprising:
transmitting, to the UE, a plurality of transport blocks (TBs) partially or fully contained within a duration of a plurality of consecutive symbols ending at a last symbol of a PDSCH transmission, when a limited-buffer rate-matching (LBRM) condition is not satisfied, wherein the LBRM condition is:
2
max
(
0
,
μ
-
μ
′
)
.
∑
i
∈
S
⌊
C
i
′
L
i
⌋
x
i
.
F
i
>
ceil
(
X
4
)
.
1
R
L
B
R
M
.
T
B
S
L
B
R
M
where: R LBRM =2/3, TBS LBRM is an LBRM transport block size and X is a maximum number of transmission layers associated with the UE for the serving cell;
S is a set of all TBs scheduled for the UE on physical downlink shared channels (PDSCHs) that are at least partially included in the plurality of consecutive symbols, and i is an index to an i-th TB within S;
C i ′ is a number of scheduled code blocks for the i-th TB;
L i is a number of orthogonal frequency-division multiplexing (OFDM) symbols assigned to the PDSCH for the i-th TB;
x i is a number of OFDM symbols of the PDSCH that are included in the plurality of consecutive symbols;
F
i
=
max
j
=
0
,
…
,
J
-
1
(
min
(
k
0
,
i
j
+
E
i
j
,
N
c
b
,
i
)
)
,
where k 0,i j is the starting location of a redundancy version (RV) for the jth transmission, E i j =min(E r ) of the scheduled code blocks for the jth transmission, where E r is a rate matching output sequence length for the r-th coded block, N cb,i is a circular buffer length;
μ corresponds to a subcarrier spacing of an active bandwidth part (BWP); and
μ′ corresponds to the subcarrier spacing of a configured BWP having the largest number of configured physical resource blocks; and
wherein X is greater than four.
13. The method of claim 12 , wherein transmitting the plurality of TBs comprises determining sizes of the plurality of TBs such that the LBRM condition is not satisfied.
14. The method of claim 12 , wherein transmitting the plurality of TBs comprises:
encoding and transmitting a first TB via one or more first transmission layers; and
encoding and transmitting a second TB via one or more second transmission layers.
15. The method of claim 12 , wherein the plurality of TBs are encoded and transmitted based on R LBRM and TBS LBRM .
16. The method of claim 12 , wherein X is given by:
a higher-layer parameter maxMIMO-Layers of the serving cell, when the higher-layer parameter has been configured in the UE by the wireless network; and
the maximum number of layers for physical downlink shared channel (PDSCH) supported by the UE for the serving cell, when the higher-layer parameter has not been configured in the UE by the wireless network.
17. The method of claim 12 comprising transmitting a PDSCH transmission to the user equipment on an active bandwidth part (BWP).
18. The method of claim 12 , comprising determining that the LBRM condition is not satisfied for the duration of the plurality of consecutive symbols ending at the last symbol of the PDSCH transmission.
19. The method of claim 12 , wherein
2
max
(
0
,
μ
-
μ
′
)
.
∑
i
∈
S
⌊
C
i
′
L
i
⌋
x
i
.
F
i
is greater than
1
R
LMRM
.
T
B
S
L
B
R
M
20. A user equipment (UE) configured to receive a physical downlink shared channel (PDSCH) from a serving cell in a wireless network, the UE comprising:
radio transceiver circuitry configured to communicate with a network node in the wireless network; and
processing circuitry operatively coupled to the radio transceiver circuitry, whereby the processing circuitry and the radio transceiver circuitry are configured to:
receive a PDSCH transmission from the serving cell on an active bandwidth part (BWP);
decode a plurality of transport blocks (TBs) partially or fully contained within a duration of a plurality of consecutive symbols ending at a last symbol of the PDSCH transmission, when a limited-buffer rate-matching (LBRM) condition is not satisfied, wherein the LBRM condition is:
2
max
(
0
,
μ
-
μ
′
)
.
∑
i
∈
S
⌊
C
i
′
L
i
⌋
x
i
.
F
i
>
ceil
(
X
4
)
.
1
R
L
B
R
M
.
T
B
S
L
B
R
M
where: R LBRM =2/3, TBS LBRM is an LBRM transport block size and X is a maximum number of transmission layers associated with the UE for the serving cell;
S is a set of all TBs scheduled for the UE on physical downlink shared channels (PDSCHs) that are at least partially included in the plurality of consecutive symbols, and i is an index to an i-th TB within S;
C i ′ is a number of scheduled code blocks for the i-th TB;
L i is a number of orthogonal frequency-division multiplexing (OFDM) symbols assigned to the PDSCH for the i-th TB;
x i is a number of OFDM symbols of the PDSCH that are included in the plurality of consecutive symbols;
F
i
=
max
j
=
0
,
…
,
J
-
1
(
min
(
k
0
,
i
j
+
E
i
j
,
N
c
b
,
i
)
)
,
where k 0,i j is the starting location of a redundancy version (RV) for the jth transmission, E i j =min(E r ) of the scheduled code blocks for the jth transmission, where E r is a rate matching output sequence length for the r-th coded block, N cb,i is a circular buffer length;
μ corresponds to a subcarrier spacing of an active bandwidth part (BWP); and
μ′ corresponds to the subcarrier spacing of a configured BWP having the largest number of configured physical resource blocks; and
wherein X is greater than four.
21. A network node configured for transmitting a physical downlink shared channel (PDSCH) to a user equipment (UE) in a cell of a wireless network, the network node comprising:
radio network interface circuitry configured to communicate with the UE; and
processing circuitry operatively coupled to the radio network interface circuitry, whereby the processing circuitry and the radio network interface circuitry are configured to:
transmit, to the UE, a plurality of transport blocks (TB s) partially or fully contained within a duration of a plurality of consecutive symbols ending at a last symbol of a PDSCH transmission, when a limited-buffer rate-matching (LBRM) condition is not satisfied, wherein the LBRM condition is:
2
max
(
0
,
μ
-
μ
′
)
.
∑
i
∈
S
⌊
C
i
′
L
i
⌋
x
i
.
F
i
>
ceil
(
X
4
)
.
1
R
L
B
R
M
.
T
B
S
L
B
R
M
where: R LBRM =2/3, TBS LBRM is an LBRM transport block size and X is a maximum number of transmission layers associated with the UE for the serving cell;
S is a set of all TBs scheduled for the UE on physical downlink shared channels (PDSCHs) that are at least partially included in the plurality of consecutive symbols, and i is an index to an i-th TB within S;
C i ′ is a number of scheduled code blocks for the i-th TB;
L i is a number of orthogonal frequency-division multiplexing (OFDM) symbols assigned to the PDSCH for the i-th TB;
x i is a number of OFDM symbols of the PDSCH that are included in the plurality of consecutive symbols;
F
i
=
max
j
=
0
,
…
,
J
-
1
(
min
(
k
0
,
i
j
+
E
i
j
,
N
c
b
,
i
)
)
,
where k 0,i j is the starting location of a redundancy version (RV) for the jth transmission, E i j =min(E r ) of the scheduled code blocks for the jth transmission, where E r is a rate matching output sequence length for the r-th coded block, N cb,i is a circular buffer length;
μ corresponds to a subcarrier spacing of an active bandwidth part (BWP); and
μ′ corresponds to the subcarrier spacing of a configured BWP having the largest number of configured physical resource blocks; and
wherein X is greater than four.