Transcript IEEE C802.16m-10/0217

Text Proposal of PC-A-MAP IE Assignment in IEEE802.16 D4 (16.3.6)
Document Number:
IEEE C802.16m-10/xxxx+8
Date Submitted:
2010-02-22
Source:
Yu-Hao Chang, Yih-Shen Chen
MediaTek Inc.
E-mail:
[email protected]
Re:
Base Contribution:
None
Purpose:
Discussion and Approval
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Outline
•
•
•
•
Overview of implicit PC-A-MAP-IE indexing
Drawback of the proposed scheme
Proposed solution
Text proposal
Overview of implicit PC-A-MAP-IE indexing
• Implicit indexing scheme was suggested in [1]
• PC-A-MAP assignment can be coupled with FFBCH
assignment
– Periodicity of PC-A-MAP-IE is controlled by that of
FFBCH
– Index of PC-A-MAP-IE is determined by FFBCH as
suggested in [1]
Example of the implicit indexing scheme
in FDD [1]
• ABS assigns FFBCH to AMS#1 in UL subframe#3 with 5ms
– Then, PC-A-MAP is automatically assigned in DL #7
– Exact location in DL#7 is determined by the order of AMS#1’s FFBCH
in UL subframe#3
DL
Subframe
#3
DL
Subframe
#4
DL
Subframe
#5
DL
Subframe
#6
DL
Subframe
#7
DL
Subframe
#0
UL
Subframe
#1
UL
Subframe
#2
UL
Subframe
#3
UL
Subframe
#4
UL
Subframe
#5
DL
Subframe
#2
DL
Subframe
#3
DL
Subframe
#4
DL
Subframe
#5
DL
Subframe
#6
DL
Subframe
#7
UL
Subframe
#2
UL
Subframe
#3
UL
Subframe
#4
UL
Subframe
#5
UL
Subframe
#6
UL
Subframe
#7
Duration2
UL
Subframe
#6
FFBCH #2
UL
Subframe
#0
FFBCH #1
Duration1
DL
Subframe
#1
UL
Subframe
#7
UL
Subframe
#0
UL
Subframe
#1
FFBCH #2
DL
Subframe
#2
PC-A-MAP
IE #2
DL
Subframe
#1
FFBCH #1
DL
Subframe
#0
(i+1)th frame
PC-A-MAP
IE #1
i-th frame
Example of the implicit indexing scheme
in H-FDD [1]
• In H-FDD systems, certain subframes can have limited transmission
due to reception of SFH
– Subframe #0, #1 and #7 are not used for UL transmission
– Subframe #3, #4 and #5 are not used for DL transmission accordingly
– Only Subframe #2 and #6 are used for both DL and UL transmission
Example of the implicit indexing scheme
in TDD [1]
• In TDD Systems,
– Total number of UL FFBCH per ‘frame’ should be same to total number of UL
PC-A-MAP IE per ‘frame’
– In example, period of FFBCH 1 frame and 2 frame for MS#1 and MS#2
respectively
Problems of the implicit indexing scheme in
FDD/H-FDD in [1]
• Resource usage is inefficient
– When FFBCH periodicity is long, it is hard to guarantee that the
number of MS in the system is invariant. Therefore, the system always
reserves more resource for PC-A-MAP-IE even when the number of
MS goes down later
• Power control command could be outdated
– The power control command from PC-A-MAP-IE is generated based
on the latest several feedback results. However, it is not applied till
certain delay later in the current design and this latency will damage the
effectiveness of power control command
• CQI report period is limited in some scenario
– In H-FDD case, the CQI report periodicity should be carefully selected
so that PC-A-MAP-IE will not happen in those time slots where uplink
transmission takes place unless additional scheduling constraint is
enforced
Proposed Assignment Rule
• In FDD/H-FDD/TDD systems, when ABS receives the
FFBCH from AMS in ith frame, ABS will update the
transmit power of that AMS in the (i+1)th frame based on
the following reasons
–
–
–
–
Better control of resource usage
Fresher power offset information
CQI feedback periodicity is flexible
Simplicity in design
• Same assignment rule for FDD/H-FDD/TDD systems
Proposed Text : Remedy #1
• Insert the following text, Table XX in line 50 of page 459 in
IEEEP802.16m/D4
For FDD/H-FDD/TDD systems, when FFBCH is assigned to AMS, the corresponding PC-AMAP IE to the AMS automatically follows the assignment location defined in Table XX. In the
table, s is defined as s = Q * m +q where
N : total number of subframes in a frame (In TDD, N=D+U; In FDD/H-FDD, N=D=U)
D : total available number of downlink subframes in a frame in TDD
total available number of subframes in a frame in downlink carrier in FDD/H-FDD
U : total available number of uplink subframes in a frame
total available number of subframes in a frame in uplink carrier in FDD/H-FDD
Q : total number of FFBCH given by Q = Nfb*UL_FEEDBACK_SIZE – LHFB/3 where Nfb is
3 in Mzone and 4 in Lzone with PUSC, and LHFB is the number of UL HARQ channels
defined in S-SFH SP1
q : the channel index specified in Feedback Allocation A-MAP IE
m : Available UL subframe index (0≤m≤U-1)
T : total number of PC-A-MAP IE in downlink subframe, T = ceil(U*Q/D)
Table XX- PC-A-MAP IE Location
Frame index
Subframe index
Channel/IE index
F-FBCH Location
i
m
q
PC-A-MAP IE
Location
i+1
(floor(s/T)) mod N
s mod T
Proposed Text : Remedy #2
• Change the line 23~24 in page 448 (Table 811) as
Power control channel resource size indicator
2
Total number of PC-A-MAP IE, NPC-AMAP-IE ,is
0b00 : 0 (No Use of PC-A-MAP IE for
UL power correction)
0b01 : 14 if UFPC is 0, or 24
0b10 : 28 if UFPC is 0, or 56
0b11 : 43 if UFPC is 0, or 86
Proposed Text : Remedy #3
• Modify Text and Figure 522 in 16.3.6.3.2.3 as below
16.3.6.3.2.3 Power Control A-MAP
Power Control A-MAP (PC-A-MAP) contains PC-A-MAP-IEs for closed-loop power control power correction of the
uplink transmission. The ABS shall transmit PC-A-MAP-IE to every AMS which
operates in closed-loop power control mode transmits FFBCH. The location of PC-A-MAP-IE is specified in Table XX.
(x2)
(x Nrep,PC-A-MAP-IE)
(x2)
(x Nrep,PC-A-MAP-IE)
Figure 522 shows the construction procedure of PC-A-MAP symbols from PC-A-MAP-IE.
The ith PC-A-MAP-IE shall have the size of 2 bits according to power correction value.
The ith and (i+1)th PC-A-MAP IEs shall be mapped to two QPSK symbols as depicted in Figure 522. Only the ith PC-AMAP may also be mapped to two QPSK symbols for transmitting to the corresponding MS with poor channel
quality.
Power scaling by sqrt(Pi) (0i  NPC-A-MAP-IE) shall be applied to the ith PC-A-MAP-IE where NPC-A-MAP-IE is the number of
PC-A-MAP-IEs and sqrt(Pi) is the value determined by the management entity to satisfy the link performance.
The QPSK symbols are repeated Nrep,PC-A-MAP-IE times, where Nrep,PC-A-MAP-IE equals two if A-A-MAP MCS selection field
in SFH SP1 is 0b0, and four if A-A-MAP MCS selection field is 0b1.
Reference
• [1] IEEE 802.16m-09/2859r2, “Text proposal
of PC-A-MAP-IE assignment in IEEE802.16
D3 (16.3.6.5.2.3)”, Jan. 2010