U.S. patent number RE46,810 [Application Number 14/856,224] was granted by the patent office on 2018-04-24 for system and method for transport block size design for multiple-input, multiple-output (mimo) in a wireless communications system.
This patent grant is currently assigned to FUTUREWEI TECHNOLOGIES, INC.. The grantee listed for this patent is Futurewei Technologies, Inc.. Invention is credited to Yufei Blankenship, Ying Jin.
United States Patent |
RE46,810 |
Jin , et al. |
April 24, 2018 |
System and method for transport block size design for
multiple-input, multiple-output (MIMO) in a wireless communications
system
Abstract
In one embodiment, a method for transmitting information
includes processing a downlink transport channel to generate a
transport block (TB) having a TB size. The TB size is selected by
selecting a modulation and coding scheme index (I.sub.TBS) and a
physical resource block index (N.sub.PRB). The TB size for the
selected I.sub.TBS and N.sub.PRB is selected so that an effective
code rate at an user equipment (UE) does not exceed a specified
threshold. The effective code rate is defined as a number of
downlink (DL) information bits including TB cyclic redundancy check
(CRC) bits and code block CRC bits divided by a number of physical
channel bits on Physical Downlink Shared Channel (PDSCH). The
transport block is mapped to multiple spatial layers. The number of
spatial layers N is greater than or equal to three. The multiple
spatial layers are transmitted to the UE.
Inventors: |
Jin; Ying (Shanghai,
CN), Blankenship; Yufei (Kildeer, IL) |
Applicant: |
Name |
City |
State |
Country |
Type |
Futurewei Technologies, Inc. |
Plano |
TX |
US |
|
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Assignee: |
FUTUREWEI TECHNOLOGIES, INC.
(Plano, TX)
|
Family
ID: |
43220137 |
Appl.
No.: |
14/856,224 |
Filed: |
September 16, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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61219321 |
Jun 22, 2009 |
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61183481 |
Jun 2, 2009 |
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Reissue of: |
12791669 |
Jun 1, 2010 |
8537750 |
Sep 17, 2013 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H04L
27/0008 (20130101); H04L 27/0008 (20130101) |
Current International
Class: |
H04W
4/00 (20090101); H04L 27/00 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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101197611 |
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Jun 2008 |
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CN |
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101384072 |
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Mar 2009 |
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CN |
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20030067412 |
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Aug 2003 |
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KR |
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20030079631 |
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Oct 2003 |
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KR |
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Other References
3GPP "3GPP TS 36.212 V8.2.0 (Mar. 2008)", Mar. 2008. cited by
examiner .
3rd Generation Partnership Project; Technical Specification Group
Radio Access Network; Requirements for further advancements for
Evolved Universal Terrestrial Radio Access (E-UTRA)
(LTE-Advanced)(Relase 8), 3GPP TR 36.913 V8.0.1, Mar. 2009, 15
pages. cited by applicant .
3rd Generation Partnership Project; Technical Specification Group
Radio Access Network; Evolved Universal Terrestrial Radio Access
(E-UTRA); Physical Channels and Modulation (Release 8), 3GPP TS
36.211 V8.6.0, Mar. 2009, 83 pages. cited by applicant .
3rd Generation Partnership Project; Technical Specification Group
Radio Access Network; Evolved Universal Terrestrial Radio Access
(E-UTRA); Multiplexing and channel coding (Release 8), 3GPP TS
36.212 V8.6.0, Mar. 2009, 59 pgs. cited by applicant .
3rd Generation Partnership Project; Technical Specification Group
Radio Access Network; Evolved Universal Terrestrial Radio Access
(E-UTRA); Physical layer procedures (Release 8), 3GPP TS 36.213
V8.6.0, Mar. 2009, 77 pages. cited by applicant .
3rd Generation Partnership Project; Technical Specification Group
Radio Access Network; Evolved Universal Terrestrial Radio Access
(E-UTRA); Physical layer procedures (Release 8), 3GPP TS 36.213
V8.7.0, May 2009, 77 pages. cited by applicant .
International Search Report with Written Opinion of the
International Searching Authority and Translation received in
Patent Cooperation Treaty Application No. PCT/CN2010/073456, dated
Sep. 9, 2010, 10 pages. cited by applicant .
Motorola, et al., "Remaining details of MCS/TBS Signalling," 3GPP
TSG RAN1#53 R1-082211, Kansas City, MO, USA, May 5-9, 2008, 4 pgs.
cited by applicant .
Ericsson, et al., "Remaining Issues with TBS & MCS Settings,"
TSG-RAN WG1 #53bis R1-082719, Warsaw, Poland, Jun. 30-Jul. 4, 2008,
5 pgs. cited by applicant .
Motorola, "TBS and MCS Signaling and Tables," 3GPP TSG RAN1 #52bis
R1-081638, Shenzhen, China, Mar. 31-Apr. 4, 2008, 14 pgs. cited by
applicant .
"3.sup.rd Generation Partnership Project; Technical Specification
Group Radio Access Network; Evolved Universal Terrestrial Radio
Access (E-UTRA); Physical Channels and Modulation (Release 8),"
3GPP TS 36.211 V8.6.0, Mar. 2009, 59 pages. cited by
applicant.
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Primary Examiner: Wassum; Luke S
Attorney, Agent or Firm: Slater Matsil, LLP
Parent Case Text
This application claims the benefit of U.S. Provisional Application
No. 61/183,481, filed on Jun. 2, 2009, entitled "System and Method
for Transport Block Size Design for Downlink Multiple-Input,
Multiple-Output (MIMO) in a Wireless Communications System," and
U.S. Provisional Application No. 61/219,321 filed on Jun. 22, 2009,
entitled "Transport Block Size Design for LTE-A Uplink MIMO," which
applications are hereby incorporated herein by reference.
Claims
What is claimed is:
1. A method for transmitting information, the method comprising:
.[.processing a downlink transport channel to generate a transport
block (TB) having a TB size, wherein the TB size is selected by:.].
selecting a modulation and coding scheme index (I.sub.TBS) and a
physical resource block index (N.sub.PRB), .[.and.]. setting
.[.the.]. .Iadd.a transport block (.Iaddend.TB.Iadd.) .Iaddend.size
for the selected I.sub.TBS and N.sub.PRB wherein an effective code
rate at a user equipment (UE) does not exceed a specified
threshold, wherein the effective code rate is defined as a number
of downlink (DL) information bits including TB cyclic redundancy
check (CRC) bits and code block CRC bits divided by a number of
physical channel bits on .Iadd.a .Iaddend.Physical Downlink Shared
Channel (PDSCH); mapping the transport block to multiple spatial
layers, wherein the number of spatial layers N is greater than or
equal to three; and transmitting the multiple spatial layers to the
UE.
2. The method of claim 1, wherein setting the TB size comprises
defining the TB size so that code block sizes with TB CRC bits and
code block CRC bits attached are aligned with Quadratic Permutation
Polynomial (QPP) sizes for turbo codes.
3. The method of claim 1, wherein the TB size is identical to
another entry in an one-layer TB size table or a two-layer TB size
table.
4. The method of claim 1, wherein the number of spatial layers N is
equal to three, and wherein the setting the TB size for the
selected I.sub.TBS and N.sub.PRB comprises: selecting the TB size
by a (I.sub.TBS,3N.sub.PRB) entry of a one-layer TBS table if
1.ltoreq.N.sub.PRB.ltoreq.36; and selecting the TB size from a
translation table if 37.ltoreq.N.sub.PRB.ltoreq.N.sub.MAX, wherein
N.sub.MAX is the maximum number of physical resource blocks that
can be allocated.
5. The method of claim 4, wherein the translation table comprises
translations from a one-layer TB size to a three-layer TB size.
6. The method of claim 4, wherein the translation table is obtained
by: obtaining a one-layer TB size (TBS_L1) by selecting a
(I.sub.TBS,N.sub.PRB) entry from the one-layer TBS table and
calculating 3.times.TBS_L1; and obtaining a three-layer TB size
(TBS_L3) by selecting the TB size in the one-layer table or a
two-layer table that is most adjacent to a calculated
3.times.TBS_L1.
7. The method of claim 6, wherein if the calculated 3.times.TBS_L1
is larger than all entries in the one-layer and two-layer table,
the three-layer TB size is selected to be 3.times.TBS_L1 with
adjustments for CRC bits and alignment with Quadratic Permutation
Polynomial (QPP) sizes for turbo coding.
8. The method of claim 4, wherein if N.sub.PRB={38, 40, 42, 44, 46,
48, 50, 52, 54, 56, 58, 60, 62, 64, 66, 68, 70, 72} and
0.ltoreq.I.sub.TBS.ltoreq.25, the TB size is selected by a
##EQU00003## entry in an equivalent 27.times.110 two-layer TBS
table constructed by a one-layer to two-layer TB size translation
table.
9. The method of claim 4, further comprising receiving the
transmitted multiple spatial layers at the UE, and using the
one-layer TBS table, or the translation table to determine a
transmitted size of the transport block.
10. The method of claim 4, wherein the translation table is
TABLE-US-00014 TBS_L1 TBS_L3 1032 3112 1064 3240 1096 3240 1128
3368 1160 3496 1192 3624 1224 3624 1256 3752 1288 3880 1320 4008
1352 4008 1384 4136 1416 4264 1480 4392 1544 4584 1608 4776 1672
4968 1736 5160 1800 5352 1864 5544 1928 5736 1992 5992 2024 5992
2088 6200 2152 6456 2216 6712 2280 6712/6968 2344 6968 2408 7224
2472 7480 2536 7480/7736 2600 7736 2664 7992 2728 8248 2792
8248/8504 2856 8504 2984 8760/9144 3112 9144/9528 3240 9528/9912
3368 9912/10296 3496 10296/10680 3624 10680/11064 3752 11064/11448
3880 11448/11832 4008 11832/12216 4136 12576 4264 12960 4392 12960
4584 13536 4776 14112 4968 14688 5160 15264 5352 15840 5544 16416
5736 16992 5992 18336 6200 18336 6456 19080 6712 19848 6968 20616
7224 21384 7480 22152 7736 22920 7992 23688 8248 24496 8504 25456
8760 26416 9144 27376 9528 28336 9912 29296 10296 30576 10680 31704
11064 32856 11448 34008 11832 35160 12216 36696 12576 37888 12960
39232 13536 40576 14112 42368 14688 43816 15264 45352 15840 46888
16416 48936 16992 51024 17568 52752 18336 55056 19080 57336 19848
59256 20616 61664 21384 63776 22152 66592 22920 68808 23688 71112
24496 73712 25456 76208 26416 78704 27376 81176 28336 84760 29296
87936 30576 90816 31704 93800 32856 97896 34008 101840 35160 105528
36696 110136 37888 115040 39232 119816 40576 119816 42368 128496
43816 133208 45352 137792 46888 142248 48936 146856 52752 157432
55056 165216 57336 171888 59256 177816 61664 185728 63776 191720
66592 199824 68808 205880 71112 214176.
11. The method of claim 1, wherein the number of spatial layers N
is equal to four, and wherein the setting the TB size for the
selected I.sub.TBS and N.sub.PRB comprises: selecting the TB size
from a translation table if 56.ltoreq.N.sub.PRB.ltoreq.N.sub.MAX,
wherein N.sub.MAX is the maximum number of physical resource blocks
that can be allocated.
12. The method of claim 11, wherein the translation table is
TABLE-US-00015 TBS_L1 TBS_L4 TBS_L1 TBS_L4 1544 6200 1608 6456 3880
15264 1672 6712 4008 15840 1736 6968 4136 16416 1800 7224 4264
16992 1864 7480 4392 17568 1928 7736 4584 18336 1992 7992 4776
19080 2024 7992 4968 19848 2088 8248 5160 20616 2152 8504 5352
21384 2216 8760 5544 22152 2280 9144 5736 22920 2344 9528 5992
23688 2408 9528 2472 9912 6456 25456 2536 10296 2600 10296 6968
28336 2664 10680 7224 29296 2728 11064 7480 29296 2792 11064 7736
30576 2856 11448 7992 31704 2984 11832 8248 32856 3112 12576 8504
34008 3240 12960 8760 35160 3368 13536 9144 36696 3496 14112 9528
37888 3624 14688 9912 39232 10296 40576 28336 115040 10680 42368
11064 43816 30576 124464 11448 45352 31704 128496 11832 46888 32856
133208 12216 48936 34008 137792 12576 51024 35160 142248 12960
51024 36696 146856 13536 55056 14112 57336 39232 157432 14688 59256
40576 161760 15264 61664 42368 169544 15840 63776 43816 175600
16416 66592 45352 181656 16992 68808 46888 187712 17568 71112 48936
195816 18336 73712 51024 203704 19080 76208 52752 211936 19848
78704 55056 220296 20616 81176 57336 230104 21384 84760 22152 87936
22920 90816 23688 93800 66592 266440 24496 97896 25456 101840 71112
284608 26416 105528 27376 110136.
13. The method of claim 11, wherein the translation table comprises
translations from a one-layer TB size to a four-layer TB size.
14. The method of claim 11, wherein the translation table is
obtained by: locating a two-layer TB size (TBS_L2(i)) for an
one-layer TB size (TBS_L1(i)) in an i.sup.th row of an one-layer to
two-layer translation table, the TBS_L1(i) being an
(I.sub.TBS,N.sub.PRB) entry of an one-layer TBS table; in a
j.sup.th row of the one-layer to two-layer translation table
identifying an one-layer TB size (TBS_L1(j)) having a TB size equal
to TBS_L2(i)); and setting the four-layer TB size for the i.sup.th
row in the one-layer to four-layer translation to the two-layer TB
size of the j.sup.th row (TBS_L2(j)).
15. The method of claim 14, wherein the four-layer TB size for the
i.sup.th row in the one-layer to four-layer translation is set to
2.times.TBS_L2(i) with adjustment for CRC bit and alignment with
QPP sizes for turbo codes if no one-layer TB size (TBS_L1(j)) has a
TB size equal to TBS_L2(i)).
16. The method of claim 11, wherein the translation table is
TABLE-US-00016 TBS_L1 TBS_L4 3752 15264 6200 24496 6712 26416 29296
115040 37888 151376 59256 236160 61664 245648 63776 254328 68808
275376.
17. A communications device comprising: a transmitter to be coupled
to at least one transmit antenna, the transmitter configured to
transmit signals with the at least one transmit antenna; a
transport channel .[.processing unit coupled to a.]. processor, the
transport channel .[.processing unit.]. .Iadd.processor
.Iaddend.configured to .[.provide transport channel processing to a
transport block (TB) provided by the processor, wherein a TB size
of the TB is selected by.].: .[.selecting.]. .Iadd.select
.Iaddend.a modulation and coding scheme index (I.sub.TBS) and a
physical resource block index (N.sub.PRB), and .[.selecting the.].
.Iadd.select a transport block (.Iaddend.TB.Iadd.) .Iaddend.size
for the selected I.sub.TBS and N.sub.PRB, wherein the effective
code rate for a user equipment (UE) does not exceed a specified
threshold for the selected TB size, wherein the effective code rate
is defined as the number of downlink (DL) information bits
including TB cyclic redundancy check (CRC) bits and code block CRC
bits divided by the number of physical channel bits on .Iadd.a
.Iaddend.Physical Downlink Shared Channel (PDSCH); and a physical
channel .[.processing unit.]. .Iadd.processor .Iaddend.coupled to
the transmitter, the physical channel .[.processing unit.].
.Iadd.processor .Iaddend.configured to provide physical channel
processing to a plurality of transport blocks provided by the
transport channel .[.processing unit.].
.Iadd.processor.Iaddend..
18. The communications device of claim 17, wherein the transport
channel processing comprises appending error check data to a
transport block, segmenting, channel coding, rate matching,
concatenating, or a combination thereof.
19. The communications device of claim 17, wherein the physical
channel processing comprises scrambling, modulation/coding scheme
selection, codeword-to-layer mapping, signal generating, or a
combination thereof.
20. The communications device of claim 17, wherein the physical
channel .[.processing unit.]. .Iadd.processor .Iaddend.is further
configured to map a transport block of the plurality of transport
blocks to multiple spatial layers, wherein the number of spatial
layers N is greater than or equal to three.
21. A communications device comprising: a transmitter to be coupled
to at least one transmit antenna, the transmitter configured to
transmit signals with the at least one transmit antenna; a
.[.processing unit to process a downlink transport channel to
generate a transport block (TB) having a TB size, wherein the
processing unit is.]. .Iadd.processor .Iaddend.configured to
.[.select the TB size by.].: .[.selecting.]. .Iadd.select
.Iaddend.a modulation and coding scheme index (I.sub.TBS) and a
physical resource block index (N.sub.PRB), and .[.setting the.].
.Iadd.set a transport block (.Iaddend.TB.Iadd.) .Iaddend.size for
the selected I.sub.TBS and N.sub.PRB wherein an effective code rate
for a user equipment (UE) does not exceed a specified threshold,
wherein the effective code rate is defined as a number of downlink
(DL) information bits including TB cyclic redundancy check (CRC)
bits and code block CRC bits divided by a number of physical
channel bits on .Iadd.a .Iaddend.Physical Downlink Shared Channel
(PDSCH); and a layer .[.mapping unit.]. .Iadd.mapper .Iaddend.to
map the transport block to multiple spatial layers, wherein the
number of spatial layers N is greater than or equal to three,
wherein the transmitter is configured to transmit the multiple
spatial layers to the UE.
22. The communications device of claim 21, wherein setting the TB
size comprises defining the TB size so that code block sizes with
TB CRC bits and code block CRC bits attached are aligned with
Quadratic Permutation Polynomial (QPP) sizes for turbo codes.
23. The communications device of claim 21, wherein the TB size is
identical to another entry in an one-layer TB size table or a
two-layer TB size table.
24. The communications device of claim 21, wherein the number of
spatial layers N is equal to three, and wherein the setting the TB
size for the selected I.sub.TBS and N.sub.PRB comprises: selecting
the TB size by a (I.sub.TBS,3N.sub.PRB) entry of a one-layer TBS
table if 1.ltoreq.N.sub.PRB.ltoreq.36; and selecting the TB size
from a translation table if 37.ltoreq.N.sub.PRB.ltoreq.N.sub.MAX,
wherein N.sub.MAX is the maximum number of physical resource blocks
that can be allocated.
25. The communications device of claim 24, wherein the translation
table comprises translations from a one-layer TB size to a
three-layer TB size.
26. The communications device of claim 24, wherein the translation
table is obtained by: obtaining a one-layer TB size (TBS_L1) by
selecting a (I.sub.TBS,N.sub.PRB) entry from the one-layer TBS
table and calculating 3.times.TBS_L1; and obtaining a three-layer
TB size (TBS_L3) by selecting the TB size in the one-layer table or
a two-layer table that is most adjacent to a calculated
3.times.TBS_L1.
27. The communications device of claim 26, wherein if the
calculated 3.times.TBS_L1 is larger than all entries in the
one-layer and two-layer table, the three-layer TB size is selected
to be 3.times.TBS_L1 with adjustments for CRC bits and alignment
with Quadratic Permutation Polynomial (QPP) sizes for turbo
coding.
28. The communications device of claim 24, wherein if
N.sub.PRB={38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, 62, 64,
66, 68, 70, 72} and 0.ltoreq.I.sub.TBS.ltoreq.25, the TB size is
selected by a ##EQU00004## entry in an equivalent 27.times.110
two-layer TBS table constructed by a one-layer to two-layer TB size
translation table.
29. The communications device of claim 21, wherein the number of
spatial layers N is equal to four, and wherein the setting the TB
size for the selected I.sub.TBS and N.sub.PRB comprises selecting
the TB size from a translation table if
56.ltoreq.N.sub.PRB.ltoreq.N.sub.MAX, wherein N.sub.MAX is the
maximum number of physical resource blocks that can be
allocated.
30. The communications device of claim 29, wherein the translation
table comprises translations from a one-layer TB size to a
four-layer TB size.
31. The communications device of claim 29, wherein the translation
table is obtained by: locating a two-layer TB size (TBS_L2(i)) for
an one-layer TB size (TBS_L1(i)) in an i.sup.th row of an one-layer
to two-layer translation table, the TBS_L1(i) being an
(I.sub.TBS,N.sub.PRB) entry of an one-layer TBS table; in a
j.sup.th row of the one-layer to two-layer translation table
identifying an one-layer TB size (TBS_L1(j)) having a TB size equal
to TBS_L2(i)); and setting the four-layer TB size for the i.sup.th
row in the one-layer to four-layer translation to the two-layer TB
size of the j.sup.th row (TBS_L2(j)).
32. The communications device of claim 31, wherein the four-layer
TB size for the i.sup.th row in the one-layer to four-layer
translation is set to 2.times.TBS_L2(i) with adjustment for CRC bit
and alignment with QPP sizes for turbo codes if no one-layer TB
size (TBS_L1(j)) has a TB size equal to TBS_L2(i)).
.Iadd.33. A method for transmitting information, the method
comprising: selecting a modulation and coding scheme index (ITBS)
and a physical resource block index (NPRB) for a transport block
(TB), and setting the TB size for the selected ITBS and NPRB
wherein an effective code rate at a user equipment (UE) does not
exceed a specified threshold, wherein the effective code rate is
defined as a number of downlink (DL) information bits including TB
cyclic redundancy check (CRC) bits and code block CRC bits divided
by a number of physical channel bits on Physical Downlink Shared
Channel (PDSCH); mapping the transport block to multiple spatial
layers, wherein the number of spatial layers N is greater than or
equal to three; and transmitting the multiple spatial layers to the
UE, wherein the number of spatial layers N is equal to three, and
wherein the setting the TB size for the selected ITBS and NPRB
comprises: selecting the TB size by a (I.sub.TBS,3N.sub.PRB) entry
of a one-layer TBS table if 1.ltoreq.NPRB.ltoreq.36; and selecting
the TB size from a translation table if 37.ltoreq.NPRB.ltoreq.NMAX,
wherein NMAX is the maximum number of physical resource blocks that
can be allocated..Iaddend.
.Iadd.34. The method of claim 33, wherein the translation table
comprises: TABLE-US-00017 TBS_L1 TBS_L3 1032 3112 1064 3240 1096
3240 1128 3368 1160 3496 1192 3624 1224 3624 1256 3752 1288 3880
1320 4008 1352 4008 1384 4136 1416 4264 1480 4392 1544 4584.
.Iaddend.
.Iadd.35. The method of claim 33, wherein the translation table
comprises: TABLE-US-00018 TBS_L1 TBS_L3 3752 11064/11448 3880
11448/11832 4008 11832/12216 4136 12576 4264 12960 4392 12960 4584
13536 4776 14112 4968 14688 5160 15264 5352 15840 5544 16416.
.Iaddend.
.Iadd.36. The method of claim 33, wherein the translation table is
TABLE-US-00019 TBS_L1 TBS_L3 16992 51024 17568 52752 18336 55056
19080 57336 19848 59256 20616 61664 21384 63776 22152 66592 22920
68808.
.Iaddend.
.Iadd.37. The method of claim 33, wherein the translation table
comprises TABLE-US-00020 TBS_L1 TBS_L3 1544 4584 1608 4776 1672
4968 1736 5160 1800 5352 1864 5544 1928 5736 1992 5992.
.Iaddend.
.Iadd.38. The method of claim 33, wherein the translation table is
TABLE-US-00021 TBS_L1 TBS_L3 27376 81176 28336 84760 29296 87936
30576 90816 31704 93800 32856 97896 34008 101840 35160 105528 36696
110136 37888 115040.
.Iaddend.
.Iadd.39. The method of claim 33, wherein setting the TB size
comprises defining the TB size so that code block sizes with TB CRC
bits and code block CRC bits attached are aligned with Quadratic
Permutation Polynomial (QPP) sizes for turbo codes..Iaddend.
.Iadd.40. The method of claim 33, wherein the TB size is identical
to another entry in an one-layer TB size table or a two-layer TB
size table..Iaddend.
.Iadd.41. A user equipment (UE) comprising: a transmitter to be
coupled to at least one transmit antenna, the transmitter
configured to transmit signals with the at least one transmit
antenna; a processor configured to select a transport block (TB)
size by: selecting a modulation and coding scheme index (ITBS) and
a physical resource block index (NPRB), and setting the TB size for
the selected ITBS and NPRB wherein an effective code rate for a
communications device does not exceed a specified threshold,
wherein the effective code rate is defined as a number of downlink
(DL) information bits including TB cyclic redundancy check (CRC)
bits and code block CRC bits divided by a number of physical
channel bits on Physical Downlink Shared Channel (PDSCH); and a
layer mapper to map the transport block to multiple spatial layers,
wherein the number of spatial layers N is greater than or equal to
three, wherein the transmitter is configured to transmit the
multiple spatial layers to the communications device..Iaddend.
.Iadd.42. The UE of claim 41, wherein setting the TB size comprises
defining the TB size so that code block sizes with TB CRC bits and
code block CRC bits attached are aligned with Quadratic Permutation
Polynomial (QPP) sizes for turbo codes..Iaddend.
.Iadd.43. The UE of claim 41, wherein the TB size is identical to
another entry in an one-layer TB size table or a two-layer TB size
table..Iaddend.
Description
TECHNICAL FIELD
The present invention relates generally to wireless communication,
and more particularly to a system and method for transport block
size (TBS) design for MIMO in a wireless communication system.
BACKGROUND
The Third Generation Partnership Project (3GPP) has decided that
Evolved Universal Mobile Telecommunications System (UMTS)
Terrestrial Radio Access (E-UTRA) evolve in future releases in
order to meet 3GPP operator requirements for the evolution of
E-UTRA and a need to meet/exceed the capabilities of International
Mobile Telecommunications (IMT) Advanced. Accordingly, Long Term
Evolution (LTE) is in the progress of evolving to LTE-Advanced.
Changes in LTE-Advanced over LTE include a target peak data rate
for a downlink (DL) to be about 1 Gbps for LTE-Advanced as compared
to 100 Mbps for LTE. In order to support such high data rates, DL
spatial multiplexing with up to eight layers is considered for
LTE-Advanced (see 3GPP TR 36.814 V0.4.1(2009-02), "Further
Advancements for E-UTRA; Physical Layer Aspects; (Release 9), which
is incorporated herein by reference), while in LTE, DL spatial
multiplexing with up to four layers is available. As a result,
changes may have to be made to facilitate the higher layer DL
spatial multiplexing for LTE-Advanced, such as redesigning control
signaling, reference signal patterns, transport block size per DL
component carrier, and so forth.
As specified in LTE-Advanced, in the DL 8-by-X single user spatial
multiplexing, up to two transport blocks may be transmitted to a
scheduled User Equipment (UE) in a subframe per DL component
carrier. Each transport block may be assigned its own modulation
and coding scheme.
With an increase in the number of supported layers for DL spatial
multiplexing in LTE-advanced, a new codeword-to-layer mapping needs
to be designed to accommodate the larger number of layers (eight as
opposed to four). Furthermore, the size of the transport blocks may
be significantly increased for the allocated resource blocks.
For uplink, the target peak data rate is 50 Mb/s in LTE system, but
for LTE-Advanced the target peak data rate of uplink is increased
to 500 Mb/s. Uplink spatial multiplexing of up to four layers is
considered for LTE-Advanced to support the higher data rates
according to 3GPP TR 36.814 V0.4.1(2009-02), "Further Advancements
for E-UTRA; Physical Layer Aspects; (Release 9)," which is
incorporated herein by reference. In contrast only a single layer
is used for LTE uplink. Therefore, many changes have to be made to
facilitate the higher layer uplink spatial multiplexing for
LTE-Advanced, such as redesigning control signaling, reference
signal patterns, transport block size per uplink component carrier,
and so on.
Hence, transport block size design for uplink and downlink are
needed for increasing peak data rate in uplink and downlink
transmission.
SUMMARY OF THE INVENTION
These and other problems are generally solved or circumvented, and
technical advantages are generally achieved, by embodiments of a
system and method for transport block size design for downlink MIMO
in a wireless communication system.
In accordance with an embodiment, a method for transmitting
information comprises processing a downlink transport channel to
generate a transport block (TB) having a TB size. The TB size is
selected by selecting a modulation and coding scheme index
(I.sub.TBS) and a physical resource block index (N.sub.PRB). The TB
size for the selected I.sub.TBS and N.sub.PRB is selected so that
an effective code rate at a user equipment (UE) does not exceed a
specified threshold. The effective code rate is defined as a number
of downlink (DL) information bits including TB cyclic redundancy
check (CRC) bits and/or code block CRC bits divided by a number of
physical channel bits on Physical Downlink Shared Channel (PDSCH).
The transport block is mapped to multiple spatial layers. The
number of spatial layers N is greater than or equal to three. The
multiple spatial layers are transmitted to the UE.
In another embodiment, a method for transmitting information
comprises processing a uplink transport channel to generate a
transport block (TB) having a TB size. The TB size is selected by
selecting a modulation and coding scheme index (I.sub.TBS) and a
physical resource block index (N.sub.PRB). The TB size for the
I.sub.TBS and the N.sub.PRB is selected so that the number of code
blocks in the TB size is one (1) or a multiple of a number of
spatial layers N. The transport block is mapped to the N spatial
layers, and the N spatial layers transmitted to a receiver.
In an alternative embodiment, a communications device comprises a
transmitter to be coupled to at least one transmit antenna. The
transmitter is configured to transmit signals with the at least one
transmit antenna. A transport channel processing unit is coupled to
a processor. The transport channel processing unit is configured to
provide transport channel processing to a transport block (TB)
provided by the processor. The TB size of the TB is selected by
selecting a modulation and coding scheme index (I.sub.TBS) and a
physical resource block index (N.sub.PRB), and setting the TB size
for the selected I.sub.TBS and N.sub.PRB so that the effective code
rate at a user equipment (UE) does not exceed a specified
threshold. The effective code rate is defined as the number of
downlink (DL) information bits including TB cyclic redundancy check
(CRC) bits and code block CRC bits divided by the number of
physical channel bits on Physical Downlink Shared Channel (PDSCH).
A physical channel processing unit is coupled to the transmitter.
The physical channel processing unit is configured to provide
physical channel processing to a plurality of transport blocks
provided by the transport channel processing unit.
In yet another, a communications device comprises a transmitter to
be coupled to at least one transmit antenna. The transmitter is
configured to transmit signals with the at least one transmit
antenna. A transport channel processing unit is coupled to a
processor. The transport channel processing unit is configured to
provide transport channel processing to a transport block (TB)
provided by the processor. The TB size of the TB is selected by
selecting a modulation and coding scheme index (I.sub.TBS) and a
physical resource block index (N.sub.PRB), and selecting the TB
size for the I.sub.TBS and N.sub.PRB so that the number of code
blocks in the TB size is one (1) or a multiple of a number of
spatial layers N. A channel interleaver is coupled to the transport
channel processing unit. The channel interleaver is configured to
interleave modulation symbols of a plurality of transport blocks. A
physical channel processing unit is coupled to the channel
interleaver and to the transmitter. The physical channel processing
unit is configured to provide physical channel processing to the
interleaved modulation symbols provided by the channel
interleaver.
The foregoing has outlined rather broadly the features and
technical advantages of the present invention in order that the
detailed description of the embodiments that follow may be better
understood. Additional features and advantages of the embodiments
will be described hereinafter which form the subject of the claims
of the invention. It should be appreciated by those skilled in the
art that the conception and specific embodiments disclosed may be
readily utilized as a basis for modifying or designing other
structures or processes for carrying out the same purposes of the
present invention. It should also be realized by those skilled in
the art that such equivalent constructions do not depart from the
spirit and scope of the invention as set forth in the appended
claims.
BRIEF DESCRIPTION OF THE DRAWINGS
For a more complete understanding of the embodiments, and the
advantages thereof, reference is now made to the following
descriptions taken in conjunction with the accompanying drawings,
in which:
FIG. 1 is a flow diagram of LTE Advanced downlink physical layer
processing;
FIGS. 2a through 2c are diagrams of three cases of transmit blocks
(TBs) to downlink layer mappings, with a number of downlink layers
being equal to two (FIG. 2a), three (FIG. 2b), and four (FIG. 2c),
where a single TB is mapped to two layers;
FIGS. 3a through 3k are diagrams of codeword-to-layer mappings in
LTE-Advanced;
FIG. 4 is a flow diagram of operations in the design of TB sizes
for a codeword-to-N-layer mapping, where N is greater than or equal
to three in accordance with embodiments of the invention;
FIG. 5, which includes FIGS. 5a and 5b, illustrates mapping a
transport block to multiple uplink layers, wherein FIG. 5a
illustrates mapping of a transport block having two code blocks to
two layers, and wherein FIG. 5b illustrates mapping of a transport
block having three code blocks to three layers, in accordance with
embodiments of the invention; and
FIG. 6 illustrates a communications device using embodiments of the
invention.
DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS
The making and using of the embodiments are discussed in detail
below. It should be appreciated, however, that the present
invention provides many applicable inventive concepts that can be
embodied in a wide variety of specific contexts. The specific
embodiments discussed are merely illustrative of specific ways to
make and use the invention, and do not limit the scope of the
invention.
The embodiments will be described in a specific context, namely a
Third Generation Partnership Project (3GPP) Long Term Evolution
Advanced (LTE-Advanced) communications system. The invention may
also be applied, however, to other communications systems, such as
UMB, WiMAX compliant communications systems, that support transport
block (TB) mapping to multiple MIMO layers, both uplink (UL) and
downlink (DL). Therefore, the discussion of LTE and LTE-Advanced
wireless communications systems should not be construed as being
limiting to either the scope or the spirit of the embodiments.
In 3GPP LTE and LTE-Advanced compliant communications systems, data
from upper network layers arrive at a physical layer as transport
blocks (TBs). At each transmission instance (for example, a
subframe in LTE), up to two TBs may be scheduled. At the physical
layer, each TB undergoes processing such as channel coding, rate
matching, scrambling, modulation, before it is mapped to MIMO
layers and sent out from the antennas. In LTE, the set of code
bits/modulation symbols corresponding to a TB is called a MIMO
codeword. Conceptually, the codeword refers to a TB and may be used
interchangeably.
In accordance with embodiments of the invention, a downlink
transport block size design will be first described, followed by an
uplink transport block design.
FIG. 1 is a flow diagram of LTE-Advanced downlink physical layer
processing.
As illustrated in FIG. 1, up to two transport blocks (TB) are input
and for each TB, a cyclic redundancy check (CRC) is attached to the
TB at Transport block CRC attachment unit 101. If the size of the
TB is larger than a preset threshold, Code block segmentation and
Code block CRC attachment unit 102 is used to split the TB into
multiple code blocks (CB) and a CRC is attached to each CB. If the
TB is not larger than the preset threshold, then the TB may not be
split into multiple CBs and the output of unit 101 are sent to unit
103.
Then, each CB is turbo-encoded in Channel Coding unit 103. In Rate
matching unit 104, the coded bits of each CB is interleaved and the
redundancy version (RV) for hybrid automatic repeat request (HARM)
is obtained from high layer signaling. The CBs may be concatenated
in a Code block concatenation unit 105 and the coded symbols to be
transmitted is scrambled in a Scrambling unit 106 to randomize the
transmission bits. The transport block size is defined within the
transport channel processing within steps 101-105 and no further
definition of the transport block size occurs during steps 106 and
beyond.
Before mapping codewords to layers, the scrambled bits may be
modulated into complex-valued symbols using Quadrature Phase Shift
Keying (QPSK), 16 Quadrature Amplitude Modulation (QAM) or 64QAM in
a Modulation Mapper unit 107. The complex-valued modulation symbols
for each codeword to be transmitted are mapped onto one or several
layers in a Layer Mapping unit 108. While, a Precoder unit 109
takes as input the vector comprising one symbol from each layer and
generates a block of vector to be mapped onto resources on each of
the antenna ports.
In a Resource Element Mapper unit 110, the precoded symbols are
mapped into time-frequency domain resource element of each antenna
port and then converted to orthogonal frequency division
multiplexing (OFDM) baseband signal in an OFDM signal generation
unit 111. The baseband signal is then upconverted to a carrier
frequency for each antenna port.
There may be several combinations of codeword-to-layer mapping in
LTE. Codeword-to-layer mapping is discussed herein in the context
of spatial multiplexing.
Let M.sub.symbol.sup.layer denote a number of modulation symbols
per layer transmitted in a LTE subframe. Due to the parallel nature
of the multiple antenna techniques used, the same number of
modulation symbols are transmitted in each layer. Let
M.sub.symbol.sup.q, q {1,2} be a total number of modulation symbols
per transport block q. When the modulation symbols for each of the
code words are mapped onto a layer,
M.sub.symbol.sup.layer=M.sub.symbol.sup.q, q {1,2}.
When the modulation symbols for a codeword are mapped onto two
layers, the number of antenna ports must be four (see 3GPP TS
36.211 V8.6.0 (2009-03), "Physical Channels and Modulation (Release
8), which is incorporate herein by reference).
FIGS. 2a through 2c are diagrams of three cases of transmit blocks
(TBs) to downlink layer mappings, with a number of downlink layers
being equal to two (FIG. 2a), three (FIG. 2b), and four (FIG. 2c).
In FIG. 2, a single TB is mapped to two layers.
FIG. 2a illustrates a single transport block (TB) mapped onto two
layers, wherein after codeword-to-layer mapping,
M.sub.symbol.sup.layer=M.sub.symbol.sup.1/2. FIG. 2b illustrates
two transport blocks mapped onto three layers, wherein after
codeword-to-layer mapping,
M.sub.symbol.sup.layer=M.sub.symbol.sup.1=M.sub.symbol.sup.2/2.
FIG. 2c illustrates two transport blocks mapped onto four layers,
wherein after codeword-to-layer mapping,
M.sub.symbol.sup.layer=M.sub.symbol.sup.1/2=M.sub.symbol.sup.2/2.
FIG. 3, which includes FIGS. 3a-3k illustrates codeword-to-layer
mappings in LTE-Advanced, wherein FIGS. 3c, 3e, and 3g illustrate
single codeword retransmissions when an initial transmission
comprises more than one codeword. In LTE-Advanced, DL spatial
multiplexing of up to eight layers is considered. In order to avoid
increasing the uplink (UL) overhead without a significant loss in
performance, up to two transport blocks (TBs) can be transmitted to
a scheduled UE in a subframe per DL component carrier.
As illustrated in FIGS. 3a-3k, codeword one (CW1) is a modulation
symbol sequence corresponding to TB one (TB1). Similarly, codeword
two (CW2) is a modulation symbol sequence corresponding to TB two
(TB2). There is a one-to-one relationship between a TB and its
modulation symbol sequence, given the modulation order and code
rate. Although the transport blocks (e.g., TB1, TB2) are not
directly mapped to the spatial layers, rather the modulation symbol
sequence (e.g., CW1, CW2) are mapped to the spatial layers, it is
understood that in discussion of mapping to spatial layers, CW1 and
TB1 may be used interchangeably, and CW2 and TB2 may be used
interchangeably. There are one-layer TBs, two-layer TBs (i.e., one
TB mapped to two layers), three-layer TBs (i.e., one TB mapped to
three layers), and four-layer TBs (i.e., one TB mapped to four
layers) in LTE-Advanced.
In particular, a TB may be mapped to three layers or four layers
when spatial multiplexing of five to eight layers is used for
transmission (as illustrated in FIGS. 3h through 3k). For example,
for the five layer (FIG. 3h) and seven layer (FIG. 3j) situations,
the following relationships exist:
For five layers, TB1 is mapped to two layers and TB2 is mapped to
three layers, thus,
M.sub.symbol.sup.layer=M.sub.symbol.sup.1/2=M.sub.symbol.sup.2/3.
For seven layers, TB1 is mapped to three layers and TB2 is mapped
to four layers, thus,
M.sub.symbol.sup.layer=M.sub.symbol.sup.1/3=M.sub.symbol.sup.2/4.
Similar relationships exist for six layer and eight layer
situations.
One-layer TB sizes and two-layer TB sizes, as defined for LTE, are
being reused in LTE-Advanced. One-layer TB size table and two-layer
TB size table are defined in LTE (see 3GPP TS 36.213 V8.6.0
(2009-03), "Physical layer procedures (Release 8), which is
incorporated herein by reference), with a first being a one-layer
TB size (TBS) table of size 27.times.110, referred to as a
one-layer TBS table, and a second being a one-layer to two-layer
TBS translation table, referred to as a two-layer TBS table. Design
principles for one-layer TB sizes and two-layer TB sizes in LTE are
described in detail below (see 3GPP TS 36.212 V8.6.0 (2009-03),
"Multiplexing and channel coding (Release 8);" 3GPP TS 36.213
V8.6.0 (2009-03), "Physical layer procedures (Release 8);"
R1-081638, "TBS and MCS Signalling and Table;"
R1-082211,--"Remaining details of MCS/TBS signaling;" and
R1-082719, "Remaining Issues with TBS & MCS Settings;" which
are incorporated herein by reference).
Several factors are taken into consideration in designing the
one-layer TB sizes. First, in order to avoid padding and reduce
receiver complexity, the one-layer TB sizes are defined so that the
code block sizes, with transport block CRC bits and code block CRC
bits attached, are aligned with Quadratic Permutation Polynomial
(QPP) sizes for turbo codes.
Second, some preferred Media Access Control (MAC) sizes should be
contained for system requirements in designing one-layer TB sizes,
such as 16, 24, 40, 56, 72, 104, 120, 152, 296, 344, 392, 440, 488,
and 536 bits.
Third, one-layer TB sizes are computed from the Modulation and
Coding Scheme (MCS) table using the reference configuration of one
(1) Orthogonal Frequency Division Multiplexed (OFDM) symbol for
control region and the four antenna ports configuration. The
one-layer TBS table is invariant of control region sizes and
antenna configurations.
Fourth, the UE may be unable to decode if the effective code rate
is greater than 1. In particular, since the UE may skip decoding a
TB in an initial transmission if the effective code rate is higher
than 0.930, this factor should be considered for designing TB sizes
with higher modulation orders, where the effective code rate is
defined as the number of DL information bits (including TB CRC bits
and code block CRC bits) divided by the number of physical channel
bits on Physical Downlink Shared Channel (PDSCH).
Fifth, every one-layer TB size should occur with sufficient number
of times, thus providing the desired flexibility in
(re)transmission schedule.
Sixth, the one-layer TB sizes with highest MCS level for every
allocated physical resource blocks lead to consistent peak rate
scaling across different bandwidths.
The one-layer TB sizes may be designed with consideration of the
above listed factors and placed in tabular form, wherein a row
index I.sub.TBS is obtained from the MCS table and a column index
N.sub.PRB denotes the number of allocated physical resource
blocks.
For 1.ltoreq.N.sub.PRB.ltoreq.110, the TB size (TBS) may be given
by (I.sub.TBS, N.sub.PRB) entry of the one-layer TBS table. The
size of the one-layer TBS table used in LTE is 27.times.110,
wherein each of the 27 rows corresponds to a distinct spectral
efficiency, and each of the 110 columns corresponds to a given
number of physical resource blocks (RB).
To signal the transmit format, including the TB size of a TB,
Downlink Control Information (DCI) is used which contains a 5-bit
MCS field. The MCS field points to the 32 rows in the MCS table. In
the MCS table, three MCS states are reserved for signaling
modulation orders for retransmission, and two overlapped MCSs for
transitioning from QPSK to 16-QAM, and from 16-QAM to 64-QAM,
respectively. Thus there are 27 distinct spectral efficiency levels
(i.e., MCS levels), corresponding to the 27 rows of the one-layer
TBS table. With the MCS field and the RB allocation, the TB size is
obtained by looking up the 27.times.110 one-layer TBS table.
For a given combination of resources blocks and spectral
efficiency, two-layer TB sizes are two times one-layer TB sizes in
principle with some adjustment given for CRC bits. Most two-layer
TB sizes occur in the one-layer TBS table, thus providing the
desired flexibility in (re)transmission schedule.
A method for obtaining the two-layer TBS table based on the
one-layer TBS table is described as follows.
First, for 1.ltoreq.N.sub.PRB.ltoreq.55, the two-layer transport
block sizes are given by the (I.sub.TBS, 2N.sub.PRB) entry of the
one-layer TBS table. Second, for 56.ltoreq.N.sub.PRB.ltoreq.110, a
baseline TBS_L1 is taken from the (I.sub.TBS, N.sub.PRB) entry of
one-layer TBS table, which is then translated into TBS_L2 using the
mapping rule shown in Table 1 below. The two-layer transport block
sizes are given by TBS_L2.
Although the two-layer TB sizes are defined by two categories
above, collectively an equivalent 27.times.110 two-layer TB sizes
is effectively defined, similar to the explicitly defined
27.times.110 one-layer TB size table.
TABLE-US-00001 TABLE 1 One-layer to two-layer transport block sizes
translation table TBS_L1 TBS_L2 1544 3112 1608 3240 1672 3368 1736
3496 1800 3624 1864 3752 1928 3880 1992 4008 2024 4008 2088 4136
2152 4264 2216 4392 2280 4584 2344 4776 2408 4776 2472 4968 2536
5160 2600 5160 2664 5352 2728 5544 2792 5544 2856 5736 2984 5992
3112 6200 3240 6456 3368 6712 3496 6968 3624 7224 3752 7480 3880
7736 4008 7992 4136 8248 4264 8504 4392 8760 4584 9144 4776 9528
4968 9912 5160 10296 5352 10680 5544 11064 5736 11448 5992 11832
6200 12576 6456 12960 6712 13536 6968 14112 7224 14688 7480 14688
7736 15264 7992 15840 8248 16416 8504 16992 8760 17568 9144 18336
9528 19080 9912 19848 10296 20616 10680 21384 11064 22152 11448
22920 11832 23688 12216 24496 12576 25456 12960 25456 13536 27376
14112 28336 14688 29296 15264 30576 15840 31704 16416 32856 16992
34008 17568 35160 18336 36696 19080 37888 19848 39232 20616 40576
21384 42368 22152 43816 22920 45352 23688 46888 24496 48936 25456
51024 26416 52752 27376 55056 28336 57336 29296 59256 30576 61664
31704 63776 32856 66592 34008 68808 35160 71112 36696 73712 37888
76208 39232 78704 40576 81176 42368 84760 43816 87936 45352 90816
46888 93800 48936 97896 51024 101840 52752 105528 55056 110136
57336 115040 59256 119816 61664 124464 63776 128496 66592 133208
68808 137792 71112 142248 73712 146856 75376 149776
A three-layer table may be designed in accordance with an
embodiment of the invention as described below. In various
embodiments, three-layer TB sizes are defined so that the code
block sizes, with TB CRC bits and code block CRC bits attached, are
aligned with QPP sizes for turbo codes. The three-layer TB sizes
are about three times one-layer TB sizes with adjustment given for
CRC bits. Advantageously, most three-layer transport block sizes
occur in the one-layer TBS table and the two-layer TBS table, thus
providing the desired flexibility in (re)transmission schedule.
Since the UE may skip decoding a TB in an initial transmission if
the effective code rate is higher than 0.930, the effective code
rates should be smaller than 0.930. This should be particularly
considered for the highest spectral efficiency, i.e.,
I.sub.TBS=26.
To be able to calculate the effective code rates, the system
configurations for up to eight layers in LTE-Advanced is discussed
below in accordance with embodiments of the invention. The number
of resource elements for data transmission is estimated, based on
which the effective code rates can then be obtained.
In 3GPP 56bis, there are two kinds of reference signals, a Channel
State Information-Reference Signal (CSI-RS) for measurement and a
Demodulation-Reference Signal (DM-RS) for demodulation. For CSI-RS,
the periodicity of its transmissions may be specified in terms of
an integer number of subframes. For rank three through eight
transmissions, a maximum of 24 Resource Elements (Res) (total) is
assigned to DM-RS in each Resource Block (RB).
Therefore, assuming one OFDM symbol is used for the control region,
eight REs per RB for LTE cell-specific RS (i.e., one antenna port
for cell-specific RS), and 24 REs per RB for demodulation reference
signals, the effective code rate can be calculated as follows:
R.sub.eff=(TBS+24+N.sub.CB.times.24)/(N.sub.PRB.times.((168-10-8-24).time-
s.N.sub.layer.times.Q.sub.m)), (1) considering the specific layout
of a RB in 3GPP LTE and LTE-Advanced system. In equation (1), TBS
denotes the transport block size, N.sub.CB denotes the number of
codeblocks in the transport block, N.sub.layer denotes the number
of spatial layers that the TB is mapped to, Q.sub.m denotes the
modulation order which can be obtained from the MCS table. In the
numerator of equation (1), the two instances of 24 refer to the
length-24 codeblock-level CRC, and the length-24 TB-level CRC,
respectively. In the denominator of equation (1), 168 is the total
number of REs in a RB assuming a normal cyclic prefix; 10 is the
number of REs for downlink control in a RB; 8 is the number of REs
for LTE cell-specific reference signals assuming one antenna port;
and 24 is the number of DM-RS in a RB. In equation (1), the CSI-RS
is not considered since it is sparse and most subframes are not
expected to contain CSI-RS. Equation (1) will be used to calculate
the effective code rates in the transport block size design. Note
that equation (1) ignores the scenario where a TB is composed of a
single CB, and only considers the scenario where a TB is composed
of multiple CBs. This is acceptable since most TB sizes have
multiple CBs when it is mapped to multiple layers.
For I.sub.TBS=26, the DL target spectral efficiency is 5.55, which
is a combination of 64-QAM with code rate 0.9250. With REs taken
out for RS and control region, it is found that the effective code
rate of a TB mapped to three layers is higher than 0.930 if the
I.sub.TBS=26 sizes in the one-layer TBS table are scaled three
times.
Therefore, in various embodiments, the three-layer TB sizes can be
divided into two parts within the row index and two parts within
the column index N.sub.PRB. Each of the four parts are designed
independently.
First, for 0.ltoreq.I.sub.TBS.ltoreq.25, the three-layer TB sizes
are three times the one-layer TB sizes in principle with some
adjustment given for CRC bits.
For 1.ltoreq.N.sub.PRB.ltoreq.36 and 0.ltoreq.I.sub.TBS.ltoreq.25,
where 36=.left brkt-bot.110/3.right brkt-bot., the three-layer TB
sizes are given by the (I.sub.TBS,3N.sub.PRB) entry of the
one-layer TBS table. This is because for
1.ltoreq.N.sub.PRB.ltoreq.36 and 0.ltoreq.I.sub.TBS.ltoreq.25, the
effective code rates for every MCS levels are less than 0.930 if
the scaled one-layer table is used. Therefore, in various
embodiments, for 1.ltoreq.N.sub.PRB.ltoreq.36 and
0.ltoreq.I.sub.TBS.ltoreq.25, the three-layer TB sizes are given by
the (I.sub.TBS,3N.sub.PRB) entry of the one-layer TBS table.
Second, for I.sub.TBS=26, the three-layer TB sizes are determined
so that the effective code rate is 0.930 or slightly lower.
Similarly, for 1.ltoreq.N.sub.PRB.ltoreq.36 and
I.sub.TBS=.ltoreq.26, many of the effective code rates are found to
be higher than 0.930 if the (I.sub.TBS,3N.sub.PRB) entry of the
one-layer TBS table is used. Thus the TB sizes are redesigned so
that the effective code rates calculated based on Equation (1),
with N.sub.layer=3 and Q.sub.m=6 (64-QAM), should be smaller than
0.930. The final TB sizes for 1.ltoreq.N.sub.PRB.ltoreq.36 and
I.sub.TBS=26 is shown in Table 2. In Table 2, for each N.sub.PRB,
two candidate TBS values are provided; the larger value is listed
in the row labelled 26, and the smaller of the two is listed in the
row labelled 26'. If only one candidate TBS value is provided for a
N.sub.PRB, then the value is used in both row 26 and row 26'.
For each .sub.NPRB, either TBS candidate (in row 26 or row 26') may
be used. It is preferable to use the larger value in row 26, so
that a slightly higher efficiency may be achieved. Alternatively,
in some embodiments, the smaller value in the row 26' can be used,
so that the TB can be received with relatively higher reliability.
In some embodiments, it is also possible to use values in row 26
for a subset of the .sub.NPRB, and use values in row 26' for the
rest. In various embodiments, all the TBS values in Table 2 are
chosen from the existing values for the one-layer and the
equivalent two-layer TBS table. This allows flexible scheduling for
the (re)transmission of a TB size. However, in some embodiments,
one of the two candidate values listed in Table 2 may be
pre-selected, e.g., by the telecommunication operator.
TABLE-US-00002 TABLE 2 Three-layer transport block sizes table with
1 .ltoreq. N.sub.PRB .ltoreq. 36 and I.sub.TBS = 26 in accordance
with an embodiment of the invention. N.sub.PRB I.sub.TBS 1 2 3 4 5
6 7 8 9 10 26.sup. 2024 4136 6200 8248 10296 12216 14112 16416
18336 20616 26' 1992 4008 5992 7992 9912 11832 13536 15840 17568
19848 N.sub.PRB I.sub.TBS 11 12 13 14 15 16 17 18 19 20 26.sup.
22920 24496 26416 29296 30576 32856 35160 36696 39232 40576 26'
22152 23688 25456 28336 29296 31704 34008 35160 37888 39232
N.sub.PRB I.sub.TBS 21 22 23 24 25 26 27 28 29 30 26.sup. 43816
45352 46888 48936 51024 52752 55056 57336 59256 61664 26' 42368
43816 45352 46888 48936 51024 52752 55056 57336 59256 N.sub.PRB
I.sub.TBS 31 32 33 34 35 36 26.sup. 63776 66592 68808 71112 71112
75376 26' 61664 63776 66592 68808 68808 75376
Additionally, for 37.ltoreq.N.sub.PRB.ltoreq.110, since many of the
effective code rates for I.sub.TBS=26 can be higher than 0.930,
three-layer TB sizes are separately designed for
0.ltoreq.I.sub.TBS.ltoreq.25 and I.sub.TBS=26.
For 37.ltoreq.N.sub.PRB.ltoreq.110 and
0.ltoreq.I.sub.TBS.ltoreq.25, a TB_L1 to TB_L3 translation table is
defined for each unique TB_L1 size in the 37-110 columns of the
one-layer TBS table. A baseline TBS_L1 is taken from the
(I.sub.TBS, N.sub.PRB) entry of the one-layer TBS table, then
3.times.TBS_L1 is compared with all entries of the one-layer and
two-layer TBS table, and the most adjacent entry will be chosen as
TBS_L3. When there are two entries that are equidistant from
3.times.TBS_L1, one value may be chosen from the two based on
considerations such as the effective code rates, data rate and
times of occurrence, and so on. Overall, there are 12 TBS_L1 values
which have two equidistant entries in the one-layer and two-layer
TBS table. These 12 TBS_L1 values are 2280, 2536, 2792, 2984, 3112,
3240, 3368, 3496, 3624, 3752, 3880 and 4008. Both equaldistant
options are listed in Table 3 for these 10 TBS_L1 values. Either
choice can be used as TBS_L3 in various embodiments. The larger one
between these two entries, underscored in Table 3 (shown below),
may be preferred due to the slightly higher data rate.
Furthermore, some 3.times.TBS_L1 are larger than all the entries in
the one-layer and two-layer TBS table, there are 10 entries which
do not have the adjacent entries in the one-layer and two-layer TBS
table that can be used as TBS_L3. These TBS_L1 values are 51024,
52752, 55056, 57336, 59256, 61664, 63776, 66592, 68808, and 71112.
For these entries, three-layer TB sizes are three times of TBS_L1
with some adjustment given for CRC bits and should be aligned with
QPP sizes for turbo codes. The 10 entries of TBS_L1 and their
corresponding TBS_L3 are shown boldfaced in Table 3. Also in Table
3, the two largest TBS_L1 values of 73712 and 75376 do not have a
corresponding TBS_L3 value specified, because 73712 and 75376 are
used only for I.sub.TBS=26 for one-layer TB sizes.
Combining the smaller TBS_L3 that can be looked up in the one-layer
and two-layer TBS table and the larger TBS_L3 that are constructed,
the one-layer to 3-layer translation table is shown in Table 3.
TABLE-US-00003 TABLE 3 One-layer to three-layer TBS translation
table with 37 .ltoreq. N.sub.PRB .ltoreq. 110 and 0 .ltoreq.
I.sub.TBS .ltoreq. 25 in accordance with an embodiment of the
invention. TBS_L1 TBS_L3 1032 3112 1064 3240 1096 3240 1128 3368
1160 3496 1192 3624 1224 3624 1256 3752 1288 3880 1320 4008 1352
4008 1384 4136 1416 4264 1480 4392 1544 4584 1608 4776 1672 4968
1736 5160 1800 5352 1864 5544 1928 5736 1992 5992 2024 5992 2088
6200 2152 6456 2216 6712 2280 6712/6968 2344 6968 2408 7224 2472
7480 2536 7480/7736 2600 7736 2664 7992 2728 8248 2792 8248/8504
2856 8504 2984 8760/9144 3112 9144/9528 3240 9528/9912 3368
9912/10296 3496 10296/10680 3624 10680/11064 3752 11064/11448 3880
11448/11832 4008 11832/12216 4136 12576 4264 12960 4392 12960 4584
13536 4776 14112 4968 14688 5160 15264 5352 15840 5544 16416 5736
16992 5992 18336 6200 18336 6456 19080 6712 19848 6968 20616 7224
21384 7480 22152 7736 22920 7992 23688 8248 24496 8504 25456 8760
26416 9144 27376 9528 28336 9912 29296 10296 30576 10680 31704
11064 32856 11448 34008 11832 35160 12216 36696 12576 37888 12960
39232 13536 40576 14112 42368 14688 43816 15264 45352 15840 46888
16416 48936 16992 51024 17568 52752 18336 55056 19080 57336 19848
59256 20616 61664 21384 63776 22152 66592 22920 68808 23688 71112
24496 73712 25456 76208 26416 78704 27376 81176 28336 84760 29296
87936 30576 90816 31704 93800 32856 97896 34008 101840 35160 105528
36696 110136 37888 115040 39232 119816 40576 119816 42368 128496
43816 133208 45352 137792 46888 142248 48936 146856 51024 154104
52752 157432 55056 165216 57336 171888 59256 177816 61664 185728
63776 191720 66592 199824 68808 205880 71112 214176 73712 N/A 75376
N/A
For the situation where N.sub.PRB={38, 40, 42, 44, 46, 48, 50, 52,
54, 56, 58, 60, 62, 64, 66, 68, 70, 72}, each (I.sub.TBS,N.sub.PRB)
entry for the three-layer TBS table can also be given by the
##EQU00001## entry in the equivalent 27.times.110 two-layer TBS
table which can be constructed by the one-layer to two-layer TB
size translation table. The TBS subset thus obtained is different
from the TBS obtained via the TB_L1 to TB_L3 translation table
defined above in Table 3 in some embodiments. However, since these
N.sub.PRB values are not consecutive, it may be more difficult to
specify or implement than using a table like Table 3 for an entire
set of consecutive N.sub.PRB values.
Again for I.sub.TBS=26 and 37.ltoreq.N.sub.PRB.ltoreq.110, the
three-layer TB sizes are redesigned based on system configurations
so that the effective code rates should be smaller than 0.930.
Equation (1) is used to calculate the effective code rates,
assuming the associated reference configuration and with
N.sub.layer=3 and Q.sub.m=6. The final TB sizes are given in Table
4. In Table 4, for each N.sub.PRB, two candidate TBS values are
provided; the larger value listed in the row labelled 26, and the
smaller listed in the row labelled 26'. If only one candidate TBS
value is provided for a N.sub.PRB, then the value is used in both
row 26 and row 26'. For each N.sub.PRB, either TBS candidate (in
row 26 or row 26') may be used. In various embodiments, it is
advantageous to use the larger value in row 26, so that a slightly
higher efficiency may be achieved. Alternatively, in some
embodiments, the smaller value in the row 26' may be used, so that
the TB can be received with relatively higher reliability.
Alternatively, some embodiments may use values in row 26 for a
subset of the N.sub.PRB, and use values in row 26' for the
rest.
In various embodiments, all the TBS values in Table 4 less than or
equal to 149776 are chosen from the existing values for the
one-layer and two-layer TB size table. Advantageously, this allows
flexible scheduling for the (re)transmission of a TB size. For
values greater than 149776 in Table 4, values in Table 3 are reused
where appropriate.
TABLE-US-00004 TABLE 4 Three-layer transport block sizes with 37
.ltoreq. N.sub.PRB .ltoreq. 110 and I.sub.TBS = 26 in accordance
with an embodiment of the invention. N.sub.PRB I.sub.TBS 37 38 39
40 26.sup. 76208 78704 81176 81176 26' 75376 76208 78704 78704
N.sub.PRB I.sub.TBS 41 42 43 44 45 46 47 48 49 50 26.sup. 84760
84760 87936 90816 90816 93800 97896 97896 101840 101840 26' 81176
81176 84760 87936 87936 90816 93800 93800 97896 97896 N.sub.PRB
I.sub.TBS 51 52 53 54 55 56 57 58 59 60 26.sup. 105528 105528
110136 110136 115040 115040 115040 119816 119816 11- 9816 26'
101840 101840 105528 105528 110136 110136 110136 115040 115040
115040 N.sub.PRB I.sub.TBS 61 62 63 64 65 66 67 68 69 70 26.sup.
124464 124464 128496 128496 133208 133208 133208 142248 142248 14-
6856 26' 119816 119816 124464 124464 128496 128496 128496 137792
137792 142248 N.sub.PRB I.sub.TBS 71 72 73 74 75 76 77 78 79 80
26.sup. 146856 146856 152976 152976 152976 152976 160032 160032
160032 16- 7752 26' 142248 142248 151376 151376 151376 151376
159096 159096 159096 165960 N.sub.PRB I.sub.TBS 81 82 83 84 85 86
87 88 89 90 26.sup. 167752 167752 173744 173744 173744 179736
179736 179736 185728 18- 5728 26' 165960 165960 171888 171888
171888 177816 177816 177816 183744 183744 N.sub.PRB I.sub.TBS 91 92
93 94 95 96 97 98 99 100 26.sup. 185728 191720 191720 191720 197712
197712 197712 203704 203704 20- 9696 26' 183744 189696 189696
189696 195816 195816 195816 201936 201936 208056 N.sub.PRB
I.sub.TBS 101 102 103 104 105 106 107 108 109 110 26.sup. 209696
209696 214176 214176 214176 214176 221680 221680 221680 22- 1680
26' 208056 208056 209696 209696 209696 209696 214176 214176 214176
214176
A four-layer table may be designed in accordance with an embodiment
of the invention as described below. In various embodiments, a
four-layer TB sizes are defined so that the code block sizes, with
TB CRC bits and code block CRC bits attached, are aligned with QPP
sizes for turbo codes. In various embodiments, four-layer TB sizes
are two times two-layer TB sizes with some adjustment given for CRC
bits. Most four-layer TB sizes occur in the one-layer TBS table,
the two-layer TBS table, and the three-layer TBS table, thus
providing the desired flexibility in (re)transmission schedule.
Since the UE may skip decoding a TB in an initial transmission if
the effective code rate is higher than 0.930, the effective code
rates should be smaller than 0.930. This should be particularly
considered for the highest spectral efficiency, i.e.,
I.sub.TBS=26.
Similar to three-layer TB size design, it is found that the
effective code rate of a TB mapped to four layers is higher than
0.930 if the I.sub.TBS=26 sizes in the one-layer TBS table are
scaled four times (or if the I.sub.TBS=26 sizes in the equivalent
two-layer TBS table are scaled twice). Therefore, in various
embodiments, the four-layer TB size can be divided into two parts:
0.ltoreq.I.sub.TBS.ltoreq.25 and I.sub.TBs=26, and again into two
parts: 1.ltoreq.N.sub.PRB.ltoreq.55 and
56.ltoreq.N.sub.PRB.ltoreq.110.
In the first part, for 0.ltoreq.I.sub.TBS.ltoreq.25, the four-layer
transport block sizes are twice the two-layer transport block sizes
in principle with some adjustment given for CRC bits.
For 1.ltoreq.N.sub.PRB.ltoreq.55 and 0.ltoreq.I.sub.TBS.ltoreq.25,
where 55=110/2, the four-layer TB sizes are given by the
(I.sub.TBS,2N.sub.PRB) entry of the two-layer TBS table. This is
because the effective code rates for every MCS levels are checked
and are found to be less than 0.930.
For 56.ltoreq.N.sub.PRB.ltoreq.110 and
0.ltoreq.I.sub.TBS.ltoreq.25, a TB_L2 to TB_L4 translation table,
as described below, is defined for each unique TB_L2 size in the
56-110 columns of the two-layer TBS table.
In the second part, for I.sub.TBS=26, the four-layer TB sizes are
determined so that the effective code rate is 0.930 or slightly
lower.
For 1.ltoreq.N.sub.PRB.ltoreq.55 and I.sub.TBS=26, many of the
effective code rates are found to be higher than 0.930 if the
(I.sub.TBS,2N.sub.PRB) entry of the two-layer TBS table is used.
Thus the TB sizes are redesigned so that the effective code rates
calculated based on Equation (1), with N.sub.layer=4 and Q.sub.m=6
(64-QAM), should be smaller than 0.930. The final TB sizes for
1.ltoreq.N.sub.PRB.ltoreq.55 and I.sub.TBS=26 is shown in Table 5.
In Table 5, for each N.sub.PRB, two candidate TBS values are
provided, the larger value is listed in the row labelled 26, and
the smaller of the two is listed in the row labelled 26'. If only
one candidate TBS value is provided for a N.sub.PRB, then the value
is used in both row 26 and row 26'. For each N.sub.PRB, either TBS
candidate (in row 26 or row 26') may be used. It is preferable to
use the larger value in row 26, so that a slightly higher
efficiency may be achieved. Alternatively, in some embodiments, the
smaller value in the row 26' can be used, so that the TB can be
received with relatively higher reliability. Some embodiments may
use values in row 26 for a subset of the N.sub.PRB, and use values
in row 26' for the rest. In one or more embodiments, all the TBS
values in Table 5 are chosen from the existing values for the
one-layer, the equivalent two-layer, and the three-layer TBS
tables. Advantageously, this allows flexible scheduling for the
(re)transmission of a TB size.
TABLE-US-00005 TABLE 5 Four-layer TB sizes table with 1 .ltoreq.
N.sub.PRB .ltoreq. 55 and I.sub.TBS = 26 in accordance with an
embodiment of the invention N.sub.PRB I.sub.TBS 1 2 3 4 5 6 7 8 9
10 26.sup. 2728 5544 8248 11064 13536 16416 19080 22152 24496 27376
26' 2664 5352 7992 10680 12960 15840 18336 21384 23688 26416
N.sub.PRB I.sub.TBS 11 12 13 14 15 16 17 18 19 20 26.sup. 30576
32856 35160 37888 40576 43816 46888 48936 52752 55056 26' 29296
31704 34008 36696 39232 42368 45352 46888 51024 52752 N.sub.PRB
I.sub.TBS 21 22 23 24 25 26 27 28 29 30 26.sup. 57336 59256 63776
66592 68808 71112 75376 76208 81176 81176 26' 55056 57336 61664
63776 66592 68808 73712 75376 78704 78704 N.sub.PRB I.sub.TBS 31 32
33 34 35 36 37 38 39 40 26.sup. 84760 87936 90816 93800 97896 97896
101840 105528 105528 110136 26' 81176 84760 87936 90816 93800 93800
97896 101840 101840 105528 N.sub.PRB I.sub.TBS 41 42 43 44 45 46 47
48 49 50 26.sup. 110136 115040 119816 119816 124464 128496 128496
133208 133208 13- 7792 26' 105528 110136 115040 115040 119816
124464 124464 128496 128496 133208 N.sub.PRB I.sub.TBS 51 52 53 54
55 26.sup. 142248 142248 146856 149776 149776 26' 137792 137792
142248 149776 149776
For 56.ltoreq.N.sub.PRB.ltoreq.110, since many of the effective
code rates for I.sub.TBS=26 can be higher than 0.930, four-layer
transport block sizes are separately designed for
0.ltoreq.I.sub.TBS.ltoreq.25 and I.sub.TBS=26.
For 0.ltoreq.I.sub.TBS.ltoreq.25, in order to ensure that TB sizes
occur sufficient times, the relationships for one-layer TB sizes
translated to two-layer TB sizes are reused as much as possible by
two-layer TB sizes translated to four-layer transport block sizes.
The translation relationship from one-layer TB sizes to two-layer
TB sizes is given in Table 1 (shown previously).
Table 1 includes unique two-layer TB size for
56.ltoreq.N.sub.PRB.ltoreq.110 under columns labeled TBS_L2, where
TBS_L1 denotes one-layer TB sizes and TBS_L2 denotes two-layer TB
sizes. For the i-th TBS_L2 entry TBS_L2(i) in Table 1, TBS_L2(i) is
used to look up the TBS_L1 entries in Table 1. When the TBS_L1(j)
is located where TBS_L1(j)=TBS_L2(i), then TBS_L4(i)=TBS_L2(j).
After the search, only twenty entries of TBS_L2(i) do not have the
corresponding TBS_L1(j) in Table 1.
The twenty TBS_L2(i) values are the largest 20 TBS_L2 in Table 1.
However only 18 TBS_L2 values need to have the translation
relationship to TBS_L4, since the largest two TBS_L2 values
{146856, 149776}, corresponding to TBS_L1 values {73712, 75376},
are only used for I.sub.TBS=26. Thus the following 18 TBS_L2 values
need to have the TBS_L4 value defined from scratch: 76208, 78704,
81176, 84760, 87936, 90816, 93800, 97896, 101840, 105528, 110136,
115040, 119816, 124464, 128496, 133208, 137792, and 142248. For
these 18 TBS_L2 values, the TBS_L4 values are found which
corresponds to 2.times.TBS_L2 with some adjustment given for CRC
bits and should be aligned with QPP sizes for turbo codes. These 18
TBS_L2 values, together with their corresponding TBS_L1 and TBS_L4
values are boldfaced in Table 6.
In Table 6, the TBS_L2 to TBS_L4 translation relationship is shown.
Table 6 repeats the TBS_L1 to TBS_L2 translation relationship shown
in Table 1.
TABLE-US-00006 TABLE 6 Two-layer to four-layer TB sizes translation
table with 55 .ltoreq. N.sub.PRB .ltoreq. 110 and 0 .ltoreq.
I.sub.TBS .ltoreq. 25 in accordance with an embodiment of the
invention TBS_L1 TBS_L2 TBS_L4 1544 3112 6200 1608 3240 6456 1672
3368 6712 1736 3496 6968 1800 3624 7224 1864 3752 7480 1928 3880
7736 1992 4008 7992 2024 4008 7992 2088 4136 8248 2152 4264 8504
2216 4392 8760 2280 4584 9144 2344 4776 9528 2408 4776 9528 2472
4968 9912 2536 5160 10296 2600 5160 10296 2664 5352 10680 2728 5544
11064 2792 5544 11064 2856 5736 11448 2984 5992 11832 3112 6200
12576 3240 6456 12960 3368 6712 13536 3496 6968 14112 3624 7224
14688 3752 7480 14688 3880 7736 15264 4008 7992 15840 4136 8248
16416 4264 8504 16992 4392 8760 17568 4584 9144 18336 4776 9528
19080 4968 9912 19848 5160 10296 20616 5352 10680 21384 5544 11064
22152 5736 11448 22920 5992 11832 23688 6200 12576 25456 6456 12960
25456 6712 13536 27376 6968 14112 28336 7224 14688 29296 7480 14688
29296 7736 15264 30576 7992 15840 31704 8248 16416 32856 8504 16992
34008 8760 17568 35160 9144 18336 36696 9528 19080 37888 9912 19848
39232 10296 20616 40576 10680 21384 42368 11064 22152 43816 11448
22920 45352 11832 23688 46888 12216 24496 48936 12576 25456 51024
12960 25456 51024 13536 27376 55056 14112 28336 57336 14688 29296
59256 15264 30576 61664 15840 31704 63776 16416 32856 66592 16992
34008 68808 17568 35160 71112 18336 36696 73712 19080 37888 76208
19848 39232 78704 20616 40576 81176 21384 42368 84760 22152 43816
87936 22920 45352 90816 23688 46888 93800 24496 48936 97896 25456
51024 101840 26416 52752 105528 27376 55056 110136 28336 57336
115040 29296 59256 119816 30576 61664 124464 31704 63776 128496
32856 66592 133208 34008 68808 137792 35160 71112 142248 36696
73712 146856 37888 76208 152976 39232 78704 157432 40576 81176
161760 42368 84760 169544 43816 87936 175600 45352 90816 181656
46888 93800 187712 48936 97896 195816 51024 101840 203704 52752
105528 211936 55056 110136 220296 57336 115040 230104 59256 119816
239656 61664 124464 248272 63776 128496 257016 66592 133208 266440
68808 137792 275608 71112 142248 284608 73712 146856 N/A 75376
149776 N/A
For I.sub.TBS=26, the four-layer TB sizes are redesigned based on
system configurations so that the effective code rates should be
smaller than 0.930. Equation (1) is used to calculate the effective
code rates, assuming the associated reference configuration and
with N.sub.layer=4 and Q.sub.m=6. The final TB sizes are found and
given in Table 7. In Table 7, for each N.sub.PRB, two candidate TBS
values are provided; the larger value listed in the row labelled
26, and the smaller listed in the row labelled 26'. If only one
candidate TBS value is provided for a then the value is used in
both row 26 and row 26'. For each N.sub.PRB, either TBS candidate
(in row 26 or row 26') may be used. It is preferable to use the
larger value in row 26, so that a slightly higher efficiency may be
achieved. Alternatively, the smaller value in the row 26' can be
used, so that the TB can be received with relatively higher
reliability. It is also possible to use values in row 26 for a
subset of the N.sub.PRB, and use values in row 26' for the
rest.
TABLE-US-00007 TABLE 7 Four-layer TB sizes with 55 .ltoreq.
N.sub.PRB .ltoreq. 110 and I.sub.TBS = 26 in accordance with an
embodiment of the invention. N.sub.PRB I.sub.TBS 56 57 58 59 60
26.sup. 155768 159096 159096 165216 165216 26' 154104 157432 157432
163488 163488 N.sub.PRB I.sub.TBS 61 62 63 64 65 66 67 68 69 70
26.sup. 169544 169544 175600 175600 181656 181656 181656 189696
189696 19- 5816 26' 167752 167752 173744 173744 179736 179736
179736 187712 187712 193768 N.sub.PRB I.sub.TBS 71 72 73 74 75 76
77 78 79 80 26.sup. 195816 195816 203704 203704 203704 203704
214176 214176 214176 22- 4048 26' 193768 193768 201936 201936
201936 201936 211936 211936 211936 221680 N.sub.PRB I.sub.TBS 81 82
83 84 85 86 87 88 89 90 26.sup. 224048 224048 230104 230104 230104
239656 239656 239656 248272 24- 8272 26' 221680 221680 227672
227672 227672 238656 238656 238656 245648 245648 N.sub.PRB
I.sub.TBS 91 92 93 94 95 96 97 98 99 100 26.sup. 248272 257632
257632 257632 263624 263624 263624 272496 272496 27- 8552 26'
245648 257016 257016 257016 263136 263136 263136 269616 269616
275608 N.sub.PRB I.sub.TBS 101 102 103 104 105 106 107 108 109 110
26.sup. 278552 278552 284608 284608 284608 284608 296720 296720
296720 29- 6720 26' 275608 275608 278552 278552 278552 278552
284608 284608 284608 284608
The four-layer TB sizes can be alternatively designed by setting
the four-layer TB sizes to be four times the one-layer TB sizes.
The above discussed design of four-layer TB sizes that are twice
the two-layer TB sizes. Theoretically, this is equivalent to
designing four-layer TB sizes that are four times the one-layer TB
sizes. However, because the two-layer TB sizes are not exactly
twice the one-layer TB sizes, a translation table based on four
times the one-layer TB sizes may be different from Table 6 for some
TBS_L1 values. On the other hand, the I.sub.TBS=26 values in Table
6 and Table 7 does not change because they are determined based on
the effective code rates.
For TBS_L1 values in the range of 1544.ltoreq.TBS_L1.ltoreq.36696,
there are four TBS_L1 values that map to different TBS_L4 values
with that in Table 6 if TBS_L4 is taken to be the closest value to
4.times.TBS_L1 in one-layer and two-layer TB sizes. The four TBS_L1
values are: 3752, 6200, 6712, and 29296. The relevant translation
to TBS_L4 is shown in Table 8.
For TBS_L1 values greater than 36696, the TBS_L4 values are
computed rather than looked up from existing one-layer and
two-layer TBS table. If TBS_L4 is taken to be the closest value to
4.times.TBS_L1, TBS_L4 entries different from those in Table 6 may
be found. For example, five TBS_L1 values, {37888, 59256, 61664,
63776, and 68808} have TBS_L4 translations different from Table 6,
as shown in Table 8. Overall, Table 8contains the TBS_L4
translation entries different with those in Table 6. Translation
for the rest of the sizes is the same as Table 6.
TABLE-US-00008 TABLE 8 Alternative one-layer to four-layer TB sizes
translation table in accordance with an embodiment of the invention
TBS_L1 TBS_L2 TBS_L4 3752 7480 15264 6200 12576 24496 6712 13536
26416 29296 59256 115040 37888 76208 151376 59256 119816 236160
61664 124464 245648 63776 128496 254328 68808 137792 275376
FIG. 4 illustrates a flow diagram of operations 300 in the design
of TB sizes for a codeword-to-N-layer mapping, where N is greater
than or equal to three (3). Operations 300 may be indicative of
operations taking place in a processor or a computer used to map
codewords to N-layers, producing a N-layer TBS table.
Operations 300 may begin with a processor selecting a row index
(I.sub.TBS) from a set of possible row indices, such as from a MCS
table (block 305). The row index specifies a modulation and coding
scheme to be used. The processor may have a list of row indices and
may start at one end of the list and continue towards the other end
of the list, for example. The processor may check to determine if
the effective code rate of a TB mapped onto N-layers using the
selected modulation and coding scheme will exceed a maximum desired
code rate (block 310).
If the effective code rate does not exceed the maximum desired code
rate, then for entries of the N-layer TBS table associated with the
row index I.sub.TRS and column index N.sub.PRB, where N.sub.PRB is
an integer within a range of [1, floor(max_N.sub.PRB/N)], the TB
size may be given by the (I.sub.TBS, N.times.N.sub.PRB) entry of
the one-layer TBS table (block 315). Here max_N.sub.PRB is the max
number of physical resource blocks that can be allocated. For
example, if the one-layer TBS table is of size 27.times.110, and
N=3, then for entries of the three-layer TBS table within range [1
to 36], where max_N.sub.PRB=110 and floor (max_N.sub.PRB/N)=36, the
entries are given by entry (I.sub.TBS, 3N.sub.PRB) of the one-layer
TBS table.
For entries where N.sub.PRB is an integer outside of the range of
[1, floor(max_N.sub.PRB/N)], the TB size may be defined using a
translation table, such as Table 3 shown above (block 320). If
possible, the entries in the translation table may be defined so
that the N-layer TBS reuses existing TB sizes, such as values in
the one-layer and two-layer TBS table (block 325). Furthermore,
some N.times.TBS_L1 entries are larger than all the entries in the
one-layer and two-layer TBS table. In one embodiment when N=3,
there are 10 entries which do not have adjacent entries in the
one-layer and two-layer TBS table that can be used as the N-layer
TBS. For a three-layer table, these TBS_L1 values are 51024, 52752,
55056, 57336, 59256, 61664, 63776, 66592, 68808, and 71112. For
these entries, three-layer TB sizes are three times of TBS_L1 with
some adjustment given for CRC bits and should be aligned with QPP
sizes for turbo codes. The 10 entries of one-layer TBS (TBS_L1) and
their corresponding three-layer TBS (TBS_L3) are shown boldfaced in
Table 3. If there are additional row indices to process (block
330), the processor may return block 305 to select another row
index, else operations 300 may terminate.
If the effective code rate exceeds the maximum desired code rate
(block 310), then entries of the N-layer TBS table that exceed the
maximum desired code rate may be redesigned so that the effective
code rate does not exceed the maximum desired code rate (block
335). If there are additional row indices to process (block 330),
the processor may return block 305 to select another row index,
else operations 300 may terminate.
Embodiments of the invention for uplink MIMO will next be
described.
Uplink spatial multiplexing of up to four layers is considered for
LTE-Advanced while only a single layer is allowed in LTE. As
specified in 3GPP TS 36.814, in the uplink single user spatial
multiplexing, up to two transport blocks can be transmitted from a
scheduled UE in a subframe per uplink component carrier. Each
transport block is likely to have its own MCS level. Depending on
the number of transmission layers, the modulation symbols
associated with each of the transport blocks are mapped onto one or
two layers according to the same principle as in Rel-8 E-UTRA
downlink spatial multiplexing.
Since in Rel-8 uplink transport block sizes are defined for one
spatial layer only, there is a need to define the uplink transport
block sizes which are mapped to two layers in Rel-10. While it is
possible to reuse the Rel-10 two-layer TB sizes defined for DL, it
is shown below that this is not conducive to the implementation of
per-layer successive interference cancellation (SIC).
As described below, embodiments of the invention provide improved
design for TB size allocation for improving uplink performance. In
various embodiments, the new transport block sizes for uplink are
designed for LTE-Advanced to facilitate successive interference
cancellation in the receiver.
Code block segmentation and successive interference cancellation
receiver will be first described because of their implications in
designing a two-layer table. A transport block generated by MAC
layer is passed to the physical layer for channel coding and other
processing before transmission over the air. As described in 3GPP
TS 36.212 V8.6.0 (2009-03), Multiplexing and channel coding, which
is incorporated herein by reference, each TB is first attached with
L=24 TB-level CRC bits. Then code block segmentation is performed
on a TB to form code blocks (CBs). The turbo encoder individually
encode each code blocks.
Let B be the TB size plus the TB-level CRC bits, i.e., B=TBS+L,
where TBS refers to the transport block size. If B is smaller than
Z, the entire TB including the TB-level CRC bits is treated as one
code block (CB) and passed to turbo encoder. If B is larger than
the maximum code block size Z, segmentation of the input bit
sequence is performed and an additional CRC sequence of L=24 bits
is attached to each code block. Here the maximum code block size is
Z=6144 which is the largest QPP turbo interleaver length. As agreed
for 3GPP LTE, the TB sizes are chosen such that no filler bits are
necessary, and the code blocks are all of the same size.
Total number of code blocks C is determined by:
TABLE-US-00009 if B .ltoreq. Z L = 0 Number of code blocks: C = 1
B' = B else L = 24 Number of code blocks: C = .left brkt-top.B /(Z
- L).right brkt-bot.. B' = B + C L end if
The code block sizes are B'/C.
When MIMO is used, modulation symbols of a TB is mapped to the
spatial layers before transmitted by the multiple transmit
antennas. At the receiver end, the received symbols of a TB are
processed in the receiver to estimate the transmitted TB. To
facilitate SIC, it is proposed in R1-091093, "Uplink SU-MIMO in
LTE-Advanced," Ericsson, 3GPP TSG-RAN WGI #56, Athens, Greece,
February 9-Feb. 13, 2009, which is incorporated herein by
reference, that "One CRC per layer" should be used, taking
advantage of the "functionality of one CRC per code block". This
leads to a proposed codeword-to-layer mapping for uplink spatial
multiplexing, as shown in Table 1. In Table 1, a codeword refers to
the sequence of modulation symbols corresponding to a TB,
M.sub.symbol.sup.layer denotes the number of modulation symbols per
layer transmitted in a LTE subframe, d.sup.(i) denotes the
modulation symbols of the i-th TB, x.sup.(i) denotes the modulation
symbol on the i-th antenna port.
TABLE-US-00010 TABLE 9 Codeword-to-layer mapping for UL spatial
multiplexing in accordance with an embodiment of the invention
Number Number of Codeword-to-layer mapping of layers code words i =
0, 1, . . . , M.sub.symb.sup.layer - 1 2 1 x.sup.(0) (i) =
d.sup.(0) (i) M.sub.symb.sup.layer = M.sub.symb.sup.(0)/2 x.sup.(1)
(i) = d.sup.(0) (M.sub.symb.sup.layer + i) 3 2 x.sup.(0) (i) =
d.sup.(0) (i) M.sub.symb.sup.layer = M.sub.symb.sup.(0) =
M.sub.symb.sup.(1)/2 x.sup.(1) (i) = d.sup.(1) (i) x.sup.(2) (i) =
d.sup.(1) (M.sub.symb.sup.layer + i) 4 2 x.sup.(0) (i) = d.sup.(0)
(i) M.sub.symb.sup.layer = M.sub.symb.sup.(0)/2 =
M.sub.symb.sup.(1)/2 x.sup.(1) (i) = d.sup.(0)
(M.sub.symb.sup.layer + i) x.sup.(2) (i) = d.sup.(1) (i) x.sup.(3)
(i) = d.sup.(1) (M.sub.symb.sup.layer + i)
This mapping allows per-layer SIC, considering that a transport
block goes through the code block segmentation process, as defined
in 3GPP TS 36.212. As defined in 3GPP TS 36.212, a TB is appended
with 24 TB-level CRC bits and passed to the code block segmentation
process. For a TB (including CRC bits) greater than 6144 bits, the
TB is segmented into code blocks. Each code block is appended with
CB-level CRC bits. Each code block (including CB-level CRC bits) is
then turbo encoded individually. With the mapping in Table 1, the
CB-level CRC can be utilized to form a per-layer CRC check, thus
allowing per-layer SIC.
Without channel interleaving to mix bits of code blocks, the
codeword to layer mapping in Table 9 would keep bits of a given
code block together, except possibly at the end of the first layer
and the beginning of the second layer. For a TB composed of an even
number of code blocks, the method maps an integer number of code
blocks to a layer, thus no CB will be divided between two
layers.
FIG. 5, which includes FIGS. 5a and 5b, illustrates mapping a
transport block to multiple uplink layers, wherein FIG. 5a
illustrates mapping of a transport block having two code blocks to
two layers, and wherein FIG. 5b illustrates mapping of a transport
block having three code blocks to three layers, in accordance with
embodiments of the invention.
FIG. 5a illustrates a mapping of a TB 505 with two code blocks to
two layers. As shown in FIG. 5a, TB 505 includes two code blocks
(CB1 510 and CB2 511). Each of the two code blocks also includes a
CB-level CRC. The mapping results in one code block in each of the
two uplink layers (shown as CB1 520 and CB2 521). Additionally,
each uplink layer has one CRC due to a per-code block CRC defined
in the LTE Rel-8.
Although shown in FIG. 5a (and in other figures discussed herein)
as being a single contiguous code block on a single layer when an
entire code block is mapped onto the single layer for simplicity
reasons (for example, CB1 520), in an actual communications system,
the code block may be spread over a layer. For example, modulation
symbols of the code block may not be in a proper order (such as due
to interleaving or some other information dispersal technique),
modulation symbols may not be contiguous (such as due to insertion
of control information, error correction/detection information, bit
puncturing, and so forth). Therefore, the illustration of a single
contiguous code block should not be construed as being limiting to
either the spirit or the scope of the embodiments.
In general, if a TB comprises an even number of code blocks
(denoted 2C), each uplink layer may be assigned C code blocks and
each code block would have a CRC. Therefore, each uplink layer has
an equivalent CRC and an uplink layer may be deemed correct if all
C code block-level CRC checks correctly, while an uplink layer may
be deemed incorrect if one or more of the C code block-level CRC
checks incorrectly. SIC may then be facilitated as an entire set of
bits of a first layer (e.g., layer one) and can be used for
interference cancellation of bits of a second layer (e.g., layer
two) when the first layer's CRC checks correctly, and vice
versa.
For C=1, i.e., the TB size is smaller than or equal to 6120 bits,
and not segmented into code blocks. In this case, only TB-level CRC
bits are attached to the TB, without any CB-level CRC bits. In this
case, the receiver may use MMSE or ML algorithm.
While the discussion focuses on the case where channel interleaving
is not used, the same discussion holds if per-layer channel
interleaving is used. With channel interleaving where bits of
different layer are interleaved separately, and an even number of
CBs, bits of a given code block will be kept in the same layer with
the codeword to layer mapping in Table 9.
The basic SIC receiver can be enhanced to exploit the fact that
each code block in LTE has CB-level CRC. One possible way of
performing SIC is discussed below for the case of one TB being
mapped to two layers. Due to the presence of CB-level CRC, a
fraction or the whole of a layer is protected by CRC bits, if a TB
is composed of two or more code blocks. Rather than requiring the
correctness of the entire layer being confirmed before interference
cancellation as required by the basic SIC, a partial interference
cancellation can be carried out as long as correctness of any part
of the layer is confirmed.
One way to perform the enhanced SIC receiver is described here.
First a 2.times.2 MMSE is first performed at the receiver. The
layer with higher SINR is identified and decoded.
(a) After turbo decoding, CBs that are fully contained in the
stronger layer are CRC checked. The CBs that are deemed correctly
received can be used to reconstruct interference. The interference
can then be cancelled from the buffered receive samples. The data
of second layer can then be estimated and decoded. Note that this
is different from the basic SIC processing that part of the bits,
vs. all the bits, of the layer can be used for cancellation. For
example, if the stronger layer carries 2.5 CBs, and only one CB is
correctly received, the correct CB can be used for
cancellation.
(b) After the processing of the stronger layer, likely with a
certain degree of interference cancelled for the weaker layer, then
the weaker layer is turbo decoded and CRC checked. If the weaker
layer (or part of it) passes the CRC check, then the weaker layer
can be used to cancel interference for the stronger layer, if the
corresponding part of the stronger layer was not detected
correctly.
(c) Iterate (a) and (b) until both layers are correctly decoded, or
no improvement is observed, or a predefined number of iterations
are reached. If both layers fail the CRC checks after a predefined
number of iterations, then both TBs are declared to be in
error.
In the above, the description included the case where a TB is
segmented into an odd number of CBs and a CB may be mapped to
layers. However, if a TB is segmented into an even number of CBs,
the SIC receiver can be simplified because no layer contains a
partial CB.
While the procedure above only discusses SIC between layers
corresponding to a TB, the same principle can be applied between
TBs if two TBs are used as in the case of 3 and 4 layers in Table
9. Since each TB has TB-level CRC, the SIC receiver can utilize
both the CB-level CRC and the TB-level CRC.
FIG. 5b illustrates a mapping of a TB 555 with three code blocks to
three layers. As shown in FIG. 5b, TB 555 includes three code
blocks (CB1 560, CB2 561, and CB3 562). Each of the three code
blocks include a CB-level CRC. The mapping results in one code
block in each of the three uplink layers (shown as CB1 570, CB2
571, and CB3 573). The use of code blocks that are multiples of
three in the TB 555 ensures enhanced SIC as described above for the
two-layer case. Similar to the two layer case, for C=1, i.e., the
TB size is smaller than or equal to 6120 bits, and not segmented
into code blocks.
The design of uplink two-layer transport block sizes will now be
described in accordance with an embodiment of the invention.
Uplink transport block sizes are defined and signaled similar to
downlink. For uplink, to signal the transmit format, including the
TB size of a TB, the DCI (downlink control information) is used
which contains a 5-bit MCS field. The MCS field points to the 32
rows in the MCS Table, "Modulation, TBS index and redundancy
version table for PUSCH," in 3GPP TS 36.213. In the MCS table,
three MCS states are reserved for signaling redundancy version for
retransmission, and two overlapped MCSs for transitioning from QPSK
to 16-QAM, and from 16-QAM to 64-QAM, respectively. Thus there are
27 distinct spectral efficiency levels (i.e., MCS levels),
corresponding to the 27 rows of the Table of one-layer transport
block sizes. With the MCS field and the RB allocation, the TB size
is obtained by looking up the 27.times.110 one-layer transport
block size table. As currently defined in 3GPP TS 36.213, the
uplink one-layer TB size table is the same as the downlink
one-layer TB size table. Although nominally, the uplink TBS table
reuses the DL TBS table and thus contains TBS for N.sub.PRB from 1
to 110, only a subset of the N.sub.PRB values are actually used for
uplink, as shown below.
While the uplink TB size table appears to be of the same dimension
as the downlink TB size table, in reality on the uplink only
certain N.sub.PRB values are valid. As specified in 3GPP TS 36.211
V8.5.0 (2008-12), Physical Channels and Modulation, which is
incorporated herein by reference, the variable
M.sub.sc.sup.PUSCH=M.sub.RB.sup.PUSCHN.sub.sc.sup.RB, where
M.sub.RB.sup.PUSCH represents the bandwidth of the PUSCH in terms
of resource blocks, and shall fulfill
M.sub.RB.sup.PUSCH=2.sup..alpha..sup.23.sup..alpha..sup.35.sup..alpha..su-
p.5.ltoreq.N.sub.RB.sup.UL where
.alpha..sub.2,.alpha..sub.3,.alpha..sub.5 is a set of non-negative
integers.
Since for 3GPP LTE, the maximum N.sub.RB.sup.UL defined is 110, the
valid M.sub.RB.sup.PUSCH values are:
##EQU00002##
M.sub.RB.sup.PUSCH in 3GPP TS 36.211 is equivalent to N.sub.PRB
which is the column index of the TB size table. Thus for the uplink
TB size table design, only N.sub.PRB of the above values need to be
considered.
Similar to downlink, the method for obtaining uplink two-layer
transport block sizes based on one-layer transport block sizes can
be given below.
(a) For 1.ltoreq.N.sub.PRB.ltoreq.55, the two-layer transport block
sizes are given by the (I.sub.TBS,2N.sub.PRB) entry of Table for
one-layer transport block sizes.
(b) For 56.ltoreq.N.sub.PRB.ltoreq.110, a baseline TBS_L1 is taken
from the (I.sub.TBS,N.sub.PRB) entry of Table for one-layer
transport block sizes, which is then translated into TBS_L2 using a
mapping rule (e.g., using Table 1). The two-layer transport block
sizes are given by TBS_L2.
However, unlike downlink transmission, for both (a) and (b), if the
transport block size is greater than 6120, the two-layer TBS need
to contain an even number of code blocks when segmented, to
facilitate SIC. Thus the TBS_L2 values obtained from the TBS tables
defined for downlink may need to be replaced by another value
TBS_L2'. Below the two-layer TBS design for
5.ltoreq.N.sub.PRB.ltoreq.110 is shown in details, as an example of
designing the entire uplink two-layer TBS. In other words, a
one-layer to two-layer TBS translation table is designed below for
the TBS in the following N.sub.PRB columns in the one-layer TBS
table: N.sub.PRB={60, 64, 72, 75, 80, 81, 90, 96, 100, 108} (3)
For N.sub.PRB values in (3), a baseline TBS_L1 is taken from the
(I.sub.TBS,N.sub.PRB) entry of Table for one-layer transport block
sizes, which is then translated into TBS_L2 using the one-layer to
two-layer TBS translation table.
If the TBS_L1 to TBS_L2 translation relationship in Table 1 is
reused, the translation table for uplink MIMO would be as shown in
Table 10, where N.sub.cb.sub._L2 column shows the number of code
blocks segmented from TBS_L2. Note that certain TBS_L1 values in
Table 1 are not included in Table 10, due to the fact that only
N.sub.PRB values in (3) need to be considered for uplink.
For TBS_L2 values with odd N.sub.cb.sub._L2 values and
N.sub.cb.sub._L2>2 in Table 10, the TBS_L2 need to be redesigned
to facilitate per-layer SIC receiver. The results of the redesign
is shown in Table 11, where TBS_L2' shows the proposed two-layer TB
size, and N.sub.cb.sub._L2' shows the number of code blocks
segmented from TBS_L2'. For each TBS_L1 entry, the corresponding
TBS_L2' value is found by using the TBS of an even number of CBs
that is closest to (2.times.TBS_L1).
In an embodiment of the invention, the TBS_L2' values for uplink
are found using the following steps:
i) Find TBS_L2 as defined for downlink in 3GPP TS 36.213;
ii) Use code block segmentation procedure to find C, the number of
CBs for TBS_L2. a) If C is even, TBS_L2 defined for downlink is
used for uplink also, i.e., TBS_L2'=TBS_L2. b) If C is odd, TBS_L2'
value is found by using the TBS of an even number of CBs that is
closest to (2.times.TBS_L1).
TABLE-US-00011 TABLE 10 One-layer to two-layer transport block
sizes translation table using relationship in Table 1 in accordance
with an embodiment of the invention. TBS_L1 TBS_L2 N.sub.cb_L2 1672
3368 1 1800 3624 1 1992 4008 1 2088 4136 1 2152 4264 1 2216 4392 1
2280 4584 1 2344 4776 1 2536 5160 1 2600 5160 1 2664 5352 1 2728
5544 1 2792 5544 1 2856 5736 1 2984 5992 1 3240 6456 2 3368 6712 2
3496 6968 2 3624 7224 2 3752 7480 2 4008 7992 2 4264 8504 2 4392
8760 2 4584 9144 2 4776 9528 2 5160 10296 2 5352 10680 2 5544 11064
2 5736 11448 2 6200 12576 3 6456 12960 3 6712 13536 3 6968 14112 3
7224 14688 3 7480 14688 3 7736 15264 3 7992 15840 3 8248 16416 3
8504 16992 3 8760 17568 3 9144 18336 3 9528 19080 4 9912 19848 4
10296 20616 4 10680 21384 4 11064 22152 4 11448 22920 4 11832 23688
4 12216 24496 5 12576 25456 5 12960 25456 5 13536 27376 5 14112
28336 5 14688 29296 5 15264 30576 5 15840 31704 6 16416 32856 6
16992 34008 6 17568 35160 6 18336 36696 6 19080 37888 7 19848 39232
7 20616 40576 7 21384 42368 7 22152 43816 8 22920 45352 8 23688
46888 8 24496 48936 8 25456 51024 9 26416 52752 9 27376 55056 9
28336 57336 10 29296 59256 10 30576 61664 11 31704 63776 11 32856
66592 11 34008 68808 12 35160 71112 12 36696 73712 13 37888 76208
13 39232 78704 13 40576 81176 14 42368 84760 14 43816 87936 15
45352 90816 15 46888 93800 16 48936 97896 16 51024 101840 17 52752
105528 18 55056 110136 18 57336 115040 19 59256 119816 20 61664
124464 21 63776 128496 21 66592 133208 22 68808 137792 23 71112
142248 24 75376 149776 25
TABLE-US-00012 TABLE 11 One-layer to two-layer transport block
sizes translation table: Redesigned Subset of Table 10 in
accordance with an embodiment of the invention. TBS_L1 TBS_L2
Ncb_L2 TBS_L2' Ncb_L2' 6200 12576 3 12216 2 6456 12960 3 12216 2
6712 13536 3 12216 2 6968 14112 3 12216 2 7224 14688 3 12216 2 7480
14688 3 12216 2 7736 15264 3 18568 4 7992 15840 3 18568 4 8248
16416 3 18568 4 8504 16992 3 18568 4 8760 17568 3 18568 4 9144
18336 3 18568 4 12216 24496 5 24456 4 12576 25456 5 24456 4 12960
25456 5 24456 4 13536 27376 5 24456 4 14112 28336 5 30936 6 14688
29296 5 30936 6 15264 30576 5 30936 6 19080 37888 7 36696 6 19848
39232 7 36696 6 20616 40576 7 43304 8 21384 42368 7 43304 8 25456
51024 9 48936 8 26416 52752 9 55416 10 27376 55056 9 55416 10 30576
61664 11 61176 10 31704 63776 11 61176 10 32856 66592 11 68040 12
36696 73712 13 73416 12 37888 76208 13 73416 12 39232 78704 13
80280 14 43816 87936 15 85656 14 45352 90816 15 92776 16 51024
101840 17 104376 18 57336 115040 19 117256 20 61664 124464 21
122376 20 63776 128496 21 128984 22 68808 137792 23 134616 22 75376
149776 25 154104 26
Similar to N.sub.PRB values in (3), the two-layer TBS corresponding
to values N.sub.PRB smaller than 56 are also found using the steps
in i) and ii). Overall, the entire two-layer TB size table is shown
below in Table 12 for all the N.sub.PRB values in (2).
TABLE-US-00013 TABLE 12 Uplink two-layer transport block size table
of size 27 .times. 35 in accordance with an embodiment of the
invention. N.sub.PRB I.sub.TBS 1 2 3 4 5 6 8 9 10 12 0 32 88 152
208 256 328 424 488 536 648 1 56 144 208 256 344 424 568 632 712
872 2 72 176 256 328 424 520 696 776 872 1064 3 104 208 328 440 568
680 904 1032 1160 1384 4 120 256 408 552 696 840 1128 1288 1416
1736 5 144 328 504 680 872 1032 1384 1544 1736 2088 6 176 392 600
808 1032 1224 1672 1864 2088 2472 7 224 472 712 968 1224 1480 1928
2216 2472 2984 8 256 536 808 1096 1384 1672 2216 2536 2792 3368 9
296 616 936 1256 1544 1864 2536 2856 3112 3752 10 328 680 1032 1384
1736 2088 2792 3112 3496 4264 11 376 776 1192 1608 2024 2408 3240
3624 4008 4776 12 440 904 1352 1800 2280 2728 3624 4136 4584 5544
13 488 1000 1544 2024 2536 3112 4136 4584 5160 6200 14 552 1128
1736 2280 2856 3496 4584 5160 5736 6968 15 600 1224 1800 2472 3112
3624 4968 5544 6200 7224 16 632 1288 1928 2600 3240 3880 5160 5992
6456 7736 17 696 1416 2152 2856 3624 4392 5736 6456 7224 8760 18
776 1544 2344 3112 4008 4776 6200 7224 7992 9528 19 840 1736 2600
3496 4264 5160 6968 7736 8504 10296 20 904 1864 2792 3752 4584 5544
7480 8248 9144 11064 21 1000 1992 2984 4008 4968 5992 7992 9144
9912 12216 22 1064 2152 3240 4264 5352 6456 8504 9528 10680 12216
23 1128 2280 3496 4584 5736 6968 9144 10296 11448 12216 24 1192
2408 3624 4968 5992 7224 9912 11064 12216 12216 25 1256 2536 3752
5160 6200 7480 10296 11448 12216 12216 26 1480 2984 4392 5992 7480
8760 11832 12216 12216 18568 N.sub.PRB I.sub.TBS 15 16 18 20 24 25
27 30 32 36 0 808 872 1000 1096 1320 1384 1480 1672 1800 1992 1
1064 1160 1288 1416 1736 1800 1992 2152 2344 2600 2 1320 1416 1608
1800 2152 2216 2408 2664 2856 3240 3 1736 1864 2088 2344 2792 2856
3112 3496 3752 4264 4 2152 2280 2600 2856 3496 3624 3880 4264 4584
5160 5 2664 2792 3112 3496 4264 4392 4776 5352 5736 6200 6 3112
3368 3752 4136 4968 5160 5736 6200 6712 7480 7 3624 3880 4392 4968
5992 6200 6712 7224 7736 8760 8 4264 4584 4968 5544 6712 6968 7480
8504 9144 9912 9 4776 5160 5736 6200 7480 7992 8504 9528 10296
11448 10 5352 5736 6200 6968 8504 8760 9528 10680 11448 12216 11
5992 6456 7224 7992 9528 9912 11064 12216 12216 12216 12 6712 7224
8248 9144 11064 11448 12216 12216 12216 18568 13 7736 8248 9144
10296 12216 12216 12216 18568 18568 18568 14 8504 9144 10296 11448
12216 12216 18568 18568 18568 20616 15 9144 9912 11064 12216 12216
18568 18568 18568 19848 22152 16 9912 10296 11832 12216 18568 18568
18568 19848 20616 23688 17 10680 11448 12216 12216 18568 18568
19848 21384 22920 24456 18 11832 12216 12216 18568 19080 19848
21384 23688 24456 30936 19 12216 12216 18568 18568 20616 21384
22920 24456 24456 30936 20 12216 12216 18568 18568 22152 22920
24456 30936 30936 34008 21 12216 18568 18568 19848 24456 24456
24456 30936 31704 36696 22 18568 18568 19080 21384 24456 24456
30936 32856 34008 36696 23 18568 18568 20616 22920 24456 30936
30936 34008 36696 43304 24 18568 19848 22152 24456 30936 30936
32856 36696 36696 43816 25 19080 20616 22920 24456 30936 31704
34008 36696 43304 45352 26 22152 23688 24456 30936 35160 36696
36696 43816 46888 55416 N.sub.PRB I.sub.TBS 40 45 48 50 54 60 64 72
75 80 0 2216 2536 2664 2792 2984 3368 3624 4008 4136 4392 1 2856
3240 3496 3624 4008 4264 4776 5160 5544 5736 2 3624 4008 4264 4584
4776 5352 5736 6456 6712 7224 3 4776 5352 5544 5736 6200 6968 7480
8504 8760 9528 4 5736 6456 6968 7224 7736 8504 9144 10296 10680
11448 5 6968 7992 8504 8760 9528 10680 11448 12216 12216 12216 6
8248 9528 9912 10296 11448 12216 12216 12216 18568 18568 7 9912
11064 11832 12216 12216 12216 18568 18568 18568 19848 8 11064 12216
12216 12216 12216 18568 18568 19848 21384 22152 9 12216 12216 12216
18568 18568 19080 20616 22920 23688 24456 10 12216 18568 18568
18568 19080 21384 22920 24456 24456 30936 11 18568 18568 19080
19848 22152 24456 24456 30936 30936 32856 12 18568 20616 22152
22920 24456 24456 30936 32856 34008 36696 13 20616 22920 24456
24456 30936 30936 32856 36696 36696 43304 14 22920 24456 24456
30936 30936 34008 36696 43304 43304 45352 15 24456 24456 30936
30936 32856 36696 36696 43816 45352 48936 16 24456 30936 31704
32856 35160 36696 43304 46888 48936 55416 17 30936 32856 35160
36696 36696 43304 45352 55416 55416 59256 18 31704 35160 36696
36696 43304 46888 48936 57336 59256 61176 19 34008 36696 43304
43816 46888 48936 55416 61176 68040 68808 20 36696 43304 45352
46888 48936 57336 59256 68808 71112 73416 21 36696 45352 48936
48936 55416 61176 61176 73416 73416 81176 22 43816 48936 48936
55416 59256 68040 68808 80280 81176 85656 23 45352 48936 55416
57336 61176 68808 73416 81176 85656 92776 24 48936 55416 59256
61176 68040 73416 80280 85656 92776 97896 25 48936 57336 61176
61176 68808 73416 81176 92776 93800 104376 26 59256 68040 71112
73416 81176 85656 93800 105528 110136 119816 N.sub.PRB I.sub.TBS 81
90 96 100 108 0 4584 5160 5352 5544 5992 1 5992 6456 6968 7224 7992
2 7224 7992 8504 9144 9528 3 9528 10680 11064 11448 12216 4 11448
12216 12216 12216 18568 5 12216 18568 18568 18568 19080 6 18568
19080 19848 20616 22920 7 19848 22152 23688 24456 24456 8 22920
24456 24456 30936 30936 9 24456 30936 30936 31704 34008 10 30936
31704 34008 35160 36696 11 32856 36696 36696 36696 43816 12 36696
43304 43816 45352 48936 13 43304 45352 48936 48936 55416 14 45352
48936 55416 57336 61176 15 48936 55416 59256 61176 68040 16 55416
59256 61176 68040 71112 17 59256 68040 71112 73416 80280 18 61176
71112 73416 80280 84760 19 71112 80280 81176 85656 93800 20 73416
84760 92776 93800 104376 21 81176 92776 97896 104376 110136 22
85656 97896 104376 110136 119816 23 93800 104376 110136 117256
122376 24 97896 110136 119816 122376 133208 25 104376 117256 122376
128984 134616 26 119816 133208 142248 154104 154104
FIG. 6 illustrates a communications device 600 in accordance with
embodiments of the invention. Communications device 600 may be a
base station (or a mobile station) communicating using spatial
multiplexing on a DL (or on an UL for a mobile station).
Communications device 600 includes a processor 605 that may be used
to execute applications and programs. Communications device 600
includes a receive chain and a transmit chain.
The transmit chain of communications device 600 includes a
transport channel processing unit 620 that may provide transport
channel processing such as applying CRC data to a transport block,
segmenting, channel coding, rate matching, concatenating, and so
on, to information to be transmitted.
Transmit chain of communications device 600 also includes a channel
interleaver 625. Channel interleaver 625 may be implemented as a
multi-layer channel interleaver with a plurality of sub-channel
interleavers, wherein there may be as many sub-channel interleavers
as there are layers that a codeword may be mapped onto. Channel
interleaver 625 may follow any of a variety of interleaver, such as
a block interleaver, bit reversal interleaver, and so forth, while
the sub-channel interleavers may be modulation-symbol or bit level
interleavers, for example.
Transmit chain of communications device 600 further includes a
physical channel processing unit 630, transmitter circuitry 635,
and a transmitter 640. Physical channel processing unit 630 may
provide the codeword-to-layer mapping function, such as those
described previously. Physical channel processing unit 630 may
provide other physical channel processing such as scrambling,
modulation/coding scheme selection and mapping, signal generating,
and so forth. Transmitter circuitry 635 may provide processing such
as parallel to serial converting, amplifying, filtering, and so on.
Transmitter 640 may transmit the information to be transmitted
using one or more transmit antennas.
Although shown in FIG. 6 as being located immediately ahead of
physical channel processing unit 630, channel interleaver 625 may
be placed in any of a variety of positions in the transmit chain of
communications device 600. Preferably the channel interleaver 625
is placed before a layer mapping unit (part of physical channel
processing unit 630). Alternatively it may be placed after the
layer mapping unit. In general, the position of channel interleaver
625 may be relatively position independent as long as it achieves
the desired interleaving effect together with the layer mapping
unit of physical channel processing unit 630.
In various embodiments, the uplink and downlink tables including
translation tables described above may be transferred and stored in
the communications device 600 prior to beginning of the
transmission. Consequently, the receiving device can use the
corresponding uplink or downlink tables to determine the transport
block size of the received transmission.
Although the present invention and its advantages have been
described in detail, it should be understood that various changes,
substitutions and alterations can be made herein without departing
from the spirit and scope of the invention as defined by the
appended claims. For example, many of the features and functions
discussed above can be implemented in software, hardware, or
firmware, or a combination thereof.
Moreover, the scope of the present application is not intended to
be limited to the particular embodiments of the process, machine,
manufacture, composition of matter, means, methods and steps
described in the specification. As one of ordinary skill in the art
will readily appreciate from the disclosure of the present
invention, processes, machines, manufacture, compositions of
matter, means, methods, or steps, presently existing or later to be
developed, that perform substantially the same function or achieve
substantially the same result as the corresponding embodiments
described herein may be utilized according to the present
invention. Accordingly, the appended claims are intended to include
within their scope such processes, machines, manufacture,
compositions of matter, means, methods, or steps.
* * * * *