IEEE C80216m-09/1533 Project IEEE 802.16 Broadband Wireless Access Working Group <http://ieee802.org/16> Title Proposed AWD Text on the Scheduling Procedure for Group Resource Allocation Date Submitted 2009-07-06 Source(s) Jeongki Kim, Youngsoo Yuk, Kiseon Ryu, Yongho Kim, Jin Sam Kwak E-mail: {chegal, sixs, ksryu, ronnykim}@lge.com LG Electronics Re: Category: AWD comments/Area: Chapter 15.2.8 (Group Resource Allocation) “Comments on AWD 15.2.8 Group Resource Allocation” Abstract Proposed text on MAC procedure for Group Resource Allocation Purpose To be discussed and adopted by TGm for the 802.16m amendment. Notice Release Patent Policy This document does not represent the agreed views of the IEEE 802.16 Working Group or any of its subgroups. It represents only the views of the participants listed in the “Source(s)” field above. It is offered as a basis for discussion. 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Further information is located at <http://standards.ieee.org/board/pat/pat-material.html> and <http://standards.ieee.org/board/pat>. 1 IEEE C80216m-09/1533 Proposed AWD Text on the Scheduling Procedure for Group Resource Allocation Jeongki Kim, Youngsoo Yuk, Kiseon Ryu, Yongho Ronny Kim, Jin Sam Kwak LG Electronics. Introduction This contribution proposes the text on Scheduling procedure for Group Resource allocation section to be included in IEEE 802.16m AWD. References [1] IEEE P802.16 Rev2/D8, “Draft IEEE Standard for Local and Metropolitan Area Networks: Air Interface for Broadband Wireless Access,” Dec. 2008. [2] IEEE 802.16m-07/002r7, “802.16m System Requirements” [3] IEEE 802.16m-08/003r6, “The Draft IEEE 802.16m System Description Document” [4] IEEE 802.16m-08/043, “Style guide for writing the IEEE 802.16m amendment” 2 IEEE C80216m-09/1533 Text proposal for inclusion in the 802.16m amendment [Add the texts and figures marked in blue and remove the texts and figures marked in red in the IEEE 802.16m-09/0010r2] ------------------------------- Start of Proposed Text #1--------------------------------------------------[Remedy 2. Modify the texts in chapter 15.2.8.3.3 as follows:] 15.2.8.3.3 Bitmaps in Group Resource Allocation [TBD] GRA uses of bitmaps to signal resource allocation information for usersAMSs within a group. These bitmaps are sent in the Group Resource Allocation IE. The first bitmap is the User Bitmap which uses 1 bit per AMS to signal which users are scheduled in the frame. The second bitmap is MIMO Bitmap which areis used to indicate the assigned MIMO mode, when multiple MIMO modes and SM parameters are supported in the group. The existence of second bitmap and the length of bits per scheduled AMS are listed in Table 31 and Table 32. MIMO Mode Set Existence of second bitmap Table 31 – SecondMIMO Bitmap Information for DL Length of bit MIMO mode indication per scheduled AMS 0b00 No - OL SU-MIMO (SFBC with non-adaptive precoder) 0b01 Yes 1 0b0: OL SU-MIMO (SFBC with non-adaptive precoder) 0b1: OL SU-MIMO (SM with non-adaptive precoder) with Mt=2 0b10 No - CL SU-MIMO with Mt=1 0b11 Yes 1 0b0: CL SU-MIMO with Mt=1 0b1: CL MU-MIMO with Mt=1, Nt=2 MIMO Mode Set Existence of second bitmap Table 32 – SecondMIMO Bitmap Information for UL Length of bit MIMO mode indication per scheduled AMS 0b00 No - OL SU-MIMO (SFBC with non-adaptive precoder) 0b01 Yes 1 0b0: OL SU-MIMO (SFBC with non-adaptive precoder) with Mt=2 0b1: OL SU-MIMO (SM with non-adaptive precoder) with Mt=2 0b10 No - OL MU-MIMO with Mt=1, TNS=2 0b11 Yes 1 0b0: CL SU-MIMO with Mt=1 0b1: CL MU-MIMO with Mt=1, TNS=2 3 IEEE C80216m-09/1533 When MIMO Mode Set of the group contains MU-MIMO, PSI Bitmap and Pairing Bitmap are appeared to determine AMS pair sharing same resource. PSI Bitmap uses 1 bit per scheduled AMS to indicate the assigned pilot stream index(PSI). Pairing Bitmap uses to indicate a pair of two AMSs using different PSI. The number of bits per pair in the Pairing Bitmap depends on the total number of pairs in the group. If there are n pairs in the group, the number of bits per pair is p = ceil[log2(n)]. The AMSs using PSI=0 is assigned an index starting from 0 to n – 1 in the same order in which they appear in the bitmap. Every p bits in the pairing bitmap are assigned to the AMS using PSI=1 in the same order in which they appear in the PSI Bitmap. These p bits carry the index of AMS with PSI=0 that is paired with corresponding AMS with PSI=1. The third bitmap is the Resource Allocation bitmap which uses n bits per AMS to signal MCS Burst Size and Resource Size for the scheduled AMS in the subframe or extended subframe that are scheduled in the frame. The scheduled AMSs may have different number of bits in the third bitmap when they are assigned different MIMO mode and SM parameter. The bit length used for a scheduled AMS is determined by the total number of effective combinations for MCS and resource size for the assigned MIMO mode with SM parameter. Effective combinations are derived by subtracting useless combinations among all possible combinations. The following steps are needed to find the effective combinations. Step 1: List all possible combination set C={ C(0,0), C(0,1), …, C(M,B) } Table 33-Combination indexes MCS/ HARQ data burst size 1 2 … B (Highest burst size) 1 C(1,1) C(1,2) … C(1,B) 2 C(2,1) C(2,2) … C(2,B) … … … … … M (Highest MCS) C(M,1) C(M,2) … C(M,B) C(m,b): Combination index for MCS m, HARQ data burst size b Step 2: For each HARQ data burst size, useless combination is chosen when it requires same resource size with a lower MCS level comparing to others due to the resource granularity. For b∈IB, m∈IM, n∈IM, and m>n, {C(m,b)} U1 if N(m,b) = N(n,b) Where U1 : Useless combination set type 1 IM : Group MCS set IB : Group HARQ burst size set N(m,b) : Required number of RUs for MCS m, HARQ data burst size b Step 3: For a given MCS, useless combination is chosen when it requires same resource size supporting a smaller HARQ data burst size than others due to the resource granularity. For m∈IM, b∈IB, d∈IB, and b>d, {C(m,b)} U2 if N(m,b) = N(m,d) Where U2 is useless combination set type 2 4 IEEE C80216m-09/1533 Step 4: Derive effective combination set (E) which is E = C-U1-U2 • Step 1: List all possible combination set C={ C(0,0), C(0,1), …, C(M,B) } • Step 1: List All possible combination set C={ C(0,0,0), C(0,0,1), … , C(I_sizeoffset, HARQ burst size, Allocation size(NLRU)) } – Group configuration IE includes • I_sizeoffset information: Minimum I_size offset and Maximum I_sizeoffset • HARQ burst size set – AMS can get all possible allocation size based on I_sizeoffset and HARQ burst size set information – AMS configures the combination table , C(I_sizeoffset, HARQ burst size, Allocation size(NLRU)), as shown in Table 33 Table 33-Combination indices HARQ Allocation size (NLRU) Burst Size I_sizeoffset 0 1 … m (Highest value) 0 (lowest value) 0 (highest value) C(0, 0, 0) C(1, 0, 0) … C(m, 0, 0) 0 1 C(0,0, 1) C(1, 0, 1) … C(m, 0, 1) … … … … … … 0 a (lowest value) C(0, 0, a) C(1, 0, a) … C(m, 0, a) 1 0 (highest value) C(0,1, 0) C(1, 0, 0) … C(m,1, 0) 1 1 C(0, 1, 1) C(1, 1, 1) … C(m,1, 1) … … … … … … n (highest value) z (lowest value) C(0, n, z) C(1, n, z) … C(m, n, z) C(m, n, z): Combination index for I_sizeoffset m, HARQ data burst size n, Allocation size z Upon receiving a Group configuration A-MAP IE, an AMS can easily know the spectral efficiency value (Modulation Value (M) * coding rate (R)) corresponding to all possible combinations as shown in table xx-1. Table xx-1- Spectral efficiency values for all possible combination indices HARQ Allocation size Burst Size (NLRU) I_sizeoffset 1 … m value) 0 (lowest 0 (highest SE(0, 0, 0) value) value) SE(1, 0, 0) … SE(m, 0, 0) 0 SE(1, 0, 1) … SE(m, 0, 1) 1 0 SE(0,0, 1) 5 (Highest IEEE C80216m-09/1533 … … 0 … … … … a (lowest SE(0, 0, a) value) SE(1, 0, a) … SE(m, 0, a) 1 0 (highest SE(0,1, 0) value) SE(1, 0, 0) … SE(m,1, 0) 1 1 SE(0, 1, 1) SE(1, 1, 1) … SE(m,1, 1) … … … … … … SE(1, n, z) … SE(m, n, z) n (highest z (lowest SE(0, n, z) value) value) SE(m,n,z): Spectral efficiency value for C(m, n, z) Step 2: A Spectral efficiency (SE) difference value is used to reduce the RAB overhead. The SE difference value is delivered to AMSs by Group configuration A-MAP IE. For each HARQ data burst size, efficient combinations are selected by using SE difference as follows. Initial SE: Lowest SE E.g.) SE (0, 0, 0), SE (0, 1, 0), ……, SE (0, n, 0) for each HARQ burst size (n) Last SE: Highest SE E.g.) SE (m, 0, a), SE (m, 1, b), ……, SE (m, n, z) for each HARQ burst size (n) For (i=Initial SE; i < last SE; i = Next SE) { Next SE = MIN ({SE} >= i + SE difference) {C(I, b, a)} -> U1, if i < {SE (I, b,a)} < Next SE } Where b∈IB, I∈IM, a∈IA U1: Useless combination set type 1 IM: Group I_SizeOffset set IA: Group Allocation sizes (N_LRU), Depends on Group I_sizeoffset set and Group HARQ burst size set IB: Group HARQ burst size set SE (I, b, a ): Spectral efficiency value (M * R) for I_sizeoffset I, Allocation size(N_LRU) a, and HARQ data burst size b Step 3: Derive effective combination set (E) which is E = C-U1 An index code is identified to each effective combination from lower MCS level and lower HARQ data burst size where n is determined by Ceil{log2(Total number of effective combinations)}. Examples of the utilizing bitmaps are shown in Figure 399-, Figure 400-, and Figure 401- and Figure 402-. 1 1 0 1 0 1 1 0 1 0 1 1 User Bitmap 0 0 1 1 1 1 Resource Allocation Bitmap Figure 399–Example of Bitmaps with Group MIMO Mode Set: DL (0b00, 0b10), UL(0b00) 6 IEEE C80216m-09/1533 1 1 0 1 1 0 1 0 1 0 1 0 0 1 User Bitmap MIMO Bitmap 1 0 0 1 1 1 Resource Allocation Bitmap Figure 400–Example of Bitmaps for Group MIMO Mode Set: DL (0b01), UL(0b01) 1 1 0 1 0 1 1 0 0 1 0 PSI Bitmap (for MU-MIMO) Pairing Pairing ID: 00 ID: 01 1 0 1 1 User Bitmap 0 0 1 0 Pairing Bitmap (for MU-MIMO with PSI=1) Pairing ID: 10 0 1 1 1 0 Resource Allocation Bitmap for MU-MIMO 0 Figure 401–Example of Bitmaps for Group MIMOMode Set: UL(0b10) 7 IEEE C80216m-09/1533 1 1 0 1 0 1 1 0 1 1 0 1 0 1 PSI Bitmap (for MU-MIMO) 0 1 Pairing ID: 0 1 1 1 User Bitmap MIMO Bitmap 0 Pairing Bitmap (for MU-MIMO with PSI=1) 1 Pairing ID: 1 0 1 1 1 0 0 Resource Allocation Bitmap for MU-MIMO Figure 402–Example of Bitmaps for Group MIMO Mode Set: DL(0b11), UL(0b11) ------------------------------- End of Proposed Text #1 --------------------------------------------------------------------------------- Start of Proposed Text #2 --------------------------------------------------[Remedy 2. Insert the below columns in Chapter 15.2.8.4.] 15.2.8.4 Error Handling Procedure In the case of the addition of AMS to group, the ABS shall include HARQ Feedback Allocation for the A-MAP IE in the Group configuration A-MAP IE. If an AMS successfully decodes the Group Configuration A-MAP IE, the AMS shall transmit ACK via HARQ ACK/NACK channel indicated in the Group configuration A-MAP IE. Upon receiving the HARQ ACK for the Group Configuration A-MAP IE, ABS shall start the group resource allocation using DL GRA A-MAP IE or UL GRA A-MAP IE. In the absence (NULL detection) of an ACK for the Group configuration A-MAP IE, the ABS shall assume that the corresponding AMS has not received the Group configuration A-MAP IE and the ABS may transmit the Group configuration A-MAP IE again for fast group configuration. In the case of the deletion of AMS from group, the ABS shall include HARQ Feedback Allocation for the A-MAP IE in the DL/UL GRA A-MAP IE. If an AMS successfully decodes the DL/UL GRA A-MAP IE for the deletion of itself from the group, the AMS shall transmit ACK via HARQ ACK/NACK channel indicated in the A-MAP IE. Upon receiving the HARQ ACK for the GRA A-MAP IE, the ABS shall delete the AMS from the group and the corresponding AMS will delete the parameters (e.g. User bitmap index, group ID, etc.) related to the group. In the absence (NULL detection) of an ACK for the GRA A-MAP IE to delete AMS from the group, the ABS shall assume that the corresponding AMS has not received the GRA A-MAP IE and the ABS may transmit the Group configuration A-MAP IE again for fast group configuration. ------------------------------- End of Proposed Text #2 --------------------------------------------------------------------------------- Start of Proposed Text #3 --------------------------------------------------[Remedy 2. Insert the below texts and figures after Chapter 15.2.8.3.2] 8 IEEE C80216m-09/1533 15.2.8.3.3 Reconfiguration of User Bitmap Index An ABS may reconfigure the User Bitmap indices of a group by sending the User Bitmap to AMSs. 15.2.8.3.3.1 ABS Operation An ABS may reconfigure the User Bitmap indices of multiple AMSs in a subframe. To reconfigure the User Bitmap indices in a group, an ABS shall include the User Bitmap in the Group Resource Allocation A-MAP IE. In the User Bitmap “1” indicates a scheduled AMS or an unscheduled AMS in a group and “0” indicates an unused bitmap index or a deleted AMS. If the Shifting indicator is set to 1 and the retransmission flag is set to 0, the De-allocation bitmap consists of “0”s of User Bitmap or the length of De-allocated AMS index is determined according to the number of “0”s of User Bitmap. Figure xx shows the example of the initial User Bitmap to reconfigure the User Bitmap indices when there is de-allocated AMSs in a group. In Figure x, the bitmap indices of AMS #5 and AMS #7 are shifted. De-allocation Bitmap AMS #1 AMS #2 AMS #3 AMS #4 AMS #5 AMS #6 AMS #7 AMS #8 1 1 0 0 1 0 1 0 User Bitmap 0 1 0 1 0 0 1 Scheduled User Bitmap 0 Figure xx: Example of an initial User Bitmap with De-allocation Bitmap If the User Bitmap is retransmitted (i.e. retransmission flag == 1), the bitmap has the same structure as the previous User Bitmap of the group and ABS shall include the ReTX Bitmap in Group Resource Allocation A-MAP IE to indicates which AMSs should shift their indices at the frame. If the Shifting indicator is set to 1 and the retransmission flag is set to 1, the De-allocation bitmap consists of “0”s of Scheduled User Bitmap or the length of De-allocated AMS index is determined according to the number of “0”s of Scheduled User Bitmap. Figure xx shows the example of the User Bitmap retransmitted to reconfigure the User Bitmap indices when there are de-allocated AMSs in a group. AMS #1 AMS #2 AMS #3 AMS #4 AMS #5 AMS #6 AMS #7 AMS #8 1 1 0 0 1 0 1 0 User Bitmap ReTx Bitmap 1 0 1 0 0 1 Scheduled User Bitmap 1 0 De-allocation Bitmap Figure xx: Example of a retransmitted User Bitmap with De-allocation Bitmap 9 IEEE C80216m-09/1533 After sending the shifting index information, the ABS shall wait for an ACK from the AMS. 15.2.8.3.3.2 AMS Operation After decoding a Group Resource Allocation A-MAP IE including a User Bitmap, an AMS can know which AMSs should shift their bitmap indices by scanning the User Bitmap. If an AMS finds that its bitmap index should be shifted, then the AMS shall shift its bitmap index and the AMS shall send an ACK to the ABS for signaling that the AMS has successfully received the shifting information. When an AMS receives the GRA A-MAP IE including the retransmitted User Bitmap (i.e. retransmission flag == 1), if the AMS did not received the User Bitmap at the previous time, the AMS assumes that the AMS has lost the pervious GRA A-MAP IE including User Bitmap and the AMS shall shift its bitmap index and send ACK to ABS via HARQ feedback channel. When an AMS receives the GRA A-MAP IE including the retransmitted User Bitmap, if the AMS has received the User Bitmap successfully at the previous time, the AMS shall not shift its bitmap index. 15.2.8.3.43 Bitmaps in Group Resource Allocation ------------------------------- End of Proposed Text #3 --------------------------------------------------- 10