1. PC-A-MAP-IE indexing for 802.16m (16.3.6) Document Number: C80216m-09/2296 Date Submitted: 2009-12-30 Source: Yu-Hao Chang, Yih-Shen Chen, Pei-Kai Liaoyuhao.chang@mediatek.com, yihshen.chen@mediatek.comyuhao.chang@mediatek.com Chih-Yuan Lin, Paul Cheng MediaTek Venue: IEEE Session #65, San Diego, U.S.A. Re: Base Contribution: N/A Purpose: To be discussed and adopted by TGm. Notice: 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. It is not binding on the contributor(s), who reserve(s) the right to add, amend or withdraw material contained herein. Release: The contributor grants a free, irrevocable license to the IEEE to incorporate material contained in this contribution, and any modifications thereof, in the creation of an IEEE Standards publication; to copyright in the IEEE’s name any IEEE Standards publication even though it may include portions of this contribution; and at the IEEE’s sole discretion to permit others to reproduce in whole or in part the resulting IEEE Standards publication. The contributor also acknowledges and accepts that this contribution may be made public by IEEE 802.16. Patent Policy: The contributor is familiar with the IEEE-SA Patent Policy and Procedures: and.http://standards.ieee.org/guides/bylaws/sect6-7.html#6http://standards.ieee.org/guides/opman/sect6.html#6.3 Further information is located at and.http://standards.ieee.org/board/pat/pat-material.htmlhttp://standards.ieee.org/board/pat

2. 2 Background and Motivation AMS adjusts its transmit power based on its power control command (or PC-A-MAP-IE) to maintain its link quality and reduce possible interference to other ABS when it is in the close-loop power control mode ABS adjusts the output power of AMS based on the received UL references, e.g., UL data or CQI feedback, of the corresponding AMS Since PC-A-MAP symbols are formed by different number of PC-A- MAP-IEs and multiple PC-A-MAP symbols are transmitted in the same A-MAP region, it is important for the close-loop power controlled AMS to effectively figure out its PC-A-MAP-IE without much signaling overhead By coupling with assignment of UL reference signal, additional explicit assignment might not be necessary –One good reference is FBCH allocation

3. 3 Schemes of PC-A-MAP-IE Index Different indexing schemes for PC-A-MAP-IE can be applied to different A-A-MAP-IE –Explicit signaling scheme Specify the complete PC-A-MAP-IE index inside A-A-MAP-IE using a [5]-bit index Demand additional capacity inside A-A-MAP-IE –Implicit signaling scheme AMS derives its PC-A-MAP-IE location information based on other known information –Coupling PC-A-MAP-IE index with FBCH allocation Suitable for the A-A-MAP-IE whose available bits is limited, e.g., UL basic A-A-MAP-IE and UL individual PA-A-MAP-IE We prefer implicit indexing scheme

4. 4 Overview of the Proposed PC-A- MAP-IE Indexing Scheme The proposed PC-A-MAP-IE indexing scheme contains the following two modes –Default mode Suitable for slow time-varying environment Implicit indexing scheme for all A-A-MAP-IEs –Enhanced mode Provides additional TPC to track the fast channel variation Explicit indexing scheme for UL GRA-A-MAP-IE while implicit indexing scheme for UL basic A-A-MAP-IE and UL individual A-A-MAP-IE

5. 5 Implicitly Indexing Scheme in Default Mode Periodicity of PC-A-MAP –Same period as FBCH period is not inappropriate –The more frequent PC-A-MAP than FBCH would be meaningless if there is no UL reference signal for UL SINR estimation Therefore, same period with FBCH is what PC-A-MAP can have at most if there is no any other UL reference signal –The less frequent PC-A-MAP than FBCH would result in lack of information for FBCH power control Fail to track the environment change

6. 6 Example of the Implicitly Indexing Scheme in Default Mode ABS assigns FBCH 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 FBCH in UL subframe#3

7. 7 Assignment Rule Suggestion FDD Systems TDD Systems –TBD Frame indexSubframe index Channel index Note FBCH Location i mq PC-A-MAP IE Location i + floor[ (m+P/2)/N ](floor(m+P/2)) mod Nq P : period of FBCH (subframe) N : # of subframes in a frame

8. 8 Some Limitation of the Default Mode TPC Scheme Periodicity of PC-A-MAP-IE is the same as CQI feedback When environment varies quickly, the previously mentioned scheme may not be fast enough to adapt to the channel variation –More frequent TPC is necessary Enhanced Mode is recommended Index for additional TPC command can be realized in both explicit and implicit ways –Explicit Index: UL GRA-A-MAP-IE –Implicit Index: UL basic A-A-MAP-IE and UL individual PA-A- MAP-IE –The existence of enhanced TPC can be signaled via a short MAC control header

9. 9 Explicit Indexing for GRA-A-MAP-IE in Enhanced Mode Indexing for AMS using UL GRA-A-MAP-IE –A [5]-bit index is used to specify the location of the PC-A-MAP- IE of each active AMS in the same group –A [5]-bit index is used to specify the location of the PC-A-MAP- IE of the first active AMS in UL GRA-A-MAP-IE while the other active AMS can find its PC-A-MAP-IE index by shifting the PC- A-MAP-IE index of the first active AMS by a fixed value. The offset value is determined by the order of corresponding AMS within active AMS in the same UL GRA-A-MAP-IE group

10. 10 Implicit Indexing for Enhanced Mode Goal: –Implicit Indexing is suitable for UL basic A-A-MAP-IE and UL individual PA-A-MAP-IE without much signaling overhead Proposed scheme: –PC-A-MAP-IE is mapped onto the logical resource unit (LRU) according to certain index, which is determined by the MLRU index reserved for the corresponding UL basic A-A-MAP-IE or UL PA-A-MAP-IE

11. 11 ABS Behavior of the Implicit Indexing Scheme in Enhanced Mode TPC (1/3)  ABS needs to prepare its A-A-MAP-IE and PC-A-MAP-IE in the following steps 1.A-A-MAP-IE encoded by the same MCS are placed in contiguous MLRUs and formed a group  Within each group, UL A-A-MAP symbols, whose additional power control command are in the same subframe, are mapped onto contiguous MLRUs while the rest of A-A-MAP symbols are placed in the remaining MLRUs reserved for the same group

12. 12 ABS Behavior of the Implicit Indexing Scheme in Enhanced Mode TPC (2/3) 2.PC-A-MAP index of the associated UL A-A-MAP is determined by the MLRU index reserved for UL A-A-MAP via a known equation  For example,  For group 1 and 2, additional PC-A-MAP of the i th AMS is placed in the i th PC-A- MAP channel reserved for group 1 and 2 UL A-A-MAP, respectively

13. 13 ABS Behavior of the Implicit Indexing Scheme in Enhanced Mode TPC (3/3) 3.To avoid possible collision between implicit indices for additional PC-A-MAP-IE and others, we allocate enhanced mode PC-A-MAP- IE for UL A-A-MAP in a separate region 4.Since enhanced mode happens less often, we may not have to reserve many PC-A-MAP channels for UL A-A-MAP in both group 1 and 2

14. 14 AMS Behavior of the Implicit Indexing Scheme in Enhanced Mode TPC  The following steps are required for AMS to identify its additional PC-A-MAP-IE implicitly 1.AMS can find its UL A-A-MAP-IE by blind decoding and thus determine the MLRU index associated with its A-A-MAP-IE 2.The MCS of PC-A-MAP-IE, which determines the size of PC-A-MAP symbol, can be implied by that of the corresponding A-MAP-IE, e.g., UL A-A-MAP-IE, or can be signaled in the broadcast channel –Option: 802.16m specifies clearly the MCS mapping rule 3.With PC-A-MAP IE symbol size, the information of MLRU index and the mapping function available, AMS can determine its PC-A-MAP symbol location. Then it can decode its PC-A-MAP-IE

15. 15 Example of the Proposed Enhanced Mode TPC Indexing Scheme Two A-A-MAP-IE groups are considered in this example, where Group 1 and 2 contains 5 and 7 A-A-MAP-IEs, respectively MCS for Group 1 and 2 is QPSK ¼ and QPSK ½, respectively The number of AMS, which needs additional TPC, of Group 1 is 1 while that of Group 2 is 2 Once AMS finds its UL A-A-MAP-IE, it can determines the MLRU index of its A-A-MAP- IE as 2 in the Group 2 If 2 PC-A-MAP channels are reserved for each A-A-MAP group, we learn that the desired PC-A-MAP-IE is in the 1 st channel of Group 2 region The modulation format of PC-A-MAP-IE can be determined by the MCS of the corresponding A-A-MAP, e.g., BPSK is applied to Group 1 while QPSK is applied to Group 2 AMS can determine the location of PC-A- MAP symbol and then decode the power control command

16. 16 Summary Default Mode TPC index scheme –Implicit indexing scheme PC-A-MAP location is coupled with FBCH allocation Enhanced Mode TPC index scheme –Explicit indexing scheme GRA-A-MAP-IE –Implicit indexing scheme UL basic A-A-MAP-IE and UL PA-A-MAP-IE

17. 17 Proposed Text Insert the following text and Table XX under the table 810- PC-A-MAP IE format of page 394 in the section 16.3.6.5.2.3 of D3 Table XX-FDD PC-A-MAP Assignment Location Frame indexSubframe indexChannel index FBCH Locationi mq PC-A-MAP IE Location i + floor[ (m+P/2)/N ](floor(m+P/2)) mod Nq