Downlink Control Signaling for Frame Structure Design of IEEE m IEEE Presentation Submission Template (Rev. 9) Document Number: IEEE S802.16m-08/149 Date Submitted: 2008 – Source: Youngsoo Yuk : Youngseob Lee : Sanggook Kim: Kiseon Ryu : LG Electronic Inc. * Venue: Orlando, FL, USA Base Contribution: IEEE C802.16m-08/149 Purpose: To be discussed and adopted by TGm for use in the IEEE m SDD Notice: This document does not represent the agreed views of the IEEE 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 Patent Policy: The contributor is familiar with the IEEE-SA Patent Policy and Procedures: and. Further information is located at and.

2 Hierarchical MAP DL-MAP UL-MAP Scheduling Info 16m Scheduling Info Frame Configuration Info Super-frame Control (Super-MAP) Subframe Configuration Info DCD UCD System Information 16e Functionalities 16m Functionalities 16m-only Entity New System Information System Information Scheduling Broadcast System Dseciptor (BSD) Configuration Scheduling Basic System Information Dedicated Channel Broadcast Channel Sub-frame Control (Sub-MAP) System Information (BSD: Broadcast System Descriptor) : C80216m-08/150 Superframe Control Channel (Super-MAP) : C80216m-08/148 Subframe Control Channel (Sub-MAP) : C80216m-08/149

3 Contents Basic Structure –SubMAP Types & Relevance Channel Structure –Per-MS Control –3 different Channels : SFCH, SubMAP Header, SubMAP (Body) Physical Resource Mapping –Multiplexing btw Control and Data –TDM, FDM –Proposed : Scalable TDM, Hybrid TDM/FDM

4 SubMAP Types and Relevance Sub-MAP –DL Scheduling –UL Grant The Relative Location of the SubMAP in a Frame –DL SubMAP : Same subframe with data –UL SubMAP : DL subframe with the fixed Subframe offset with data

5 Channel Structure SFCH (Subframe Control Header) –Two Roles Subframe-related information SubMAP for Broadcast channel –MCS of SFCH QPSK Either Fixed Format or Described by SuperMAP The reference MCS for the corresponding subframe 95% coverage with less than 1% FER No CRC applied. FieldContents Subframe Information Sub-frame grouping information RB Configuration Index Group ACK etc SubMAP Information Total Sub-MAP Size Next Sub-MAP (Header) MCS (option 1 in slide #7) Number of Sub-MAPs for specific types and MCS (option 2 in slide #7) Broadcast Channel Information Number of the allocated resources or Index of RB configuration for the broadcast channel

6 Channel Structure SubMAP (body) –Scheduling Channel –Per-MS (Separate Coding) Identifying MS by CRC with MS-ID or CID Masking Rate Controlled (with limited power control) – multiple MCS –Multiple Types DL/UL Ordinary SubMAP DL MBMS SubMAP UL Power Control SubMAP Persistent or Group Scheduling SubMAP for VoIP –Same sizes with different types : at most 2~3 sizes FieldsDetailed Contents Resource Assignment Information Resource Allocation Information Duration/Persistent Allocation Information Resource Type Information (Distributed/Localized) Resource Size (6 symbol /5 symbol) Persistent and/or Group Scheduling Information for VoIP MSs MIMO Information Closed-loop/Open-loop Rank information PMI DL/UL Collaborative MIMO Information Transmit Format Information Modulation and Coding (MCS) Payload Size H-ARQ Information H-ARQ process ID New Data Indicator Retransmission Sequence Number Redundancy Version Transmit Power Information Uplink Closed-loop Power Control Bit Downlink Power Boosting Information CRC MS ID or (Reduced) CID embedded CRC

7 Channel Structure SubMAP Header –Decoding Information of multiple SubMAPs  to avoid blind decoding –Number of SubMAPs having same MCS and same sizes –Separately (a) or Jointly (c) Encoded –Trade-off btw overhead and MS complexity

8 Physical Resource Mapping for SubMAP Resource allocation : TDM (by symbol) or FDM (by RB (subchannel)) Considerations –Latency : HARQ feedback delay –Microsleep and MS complexity –Granularity and spectral efficiency –Controllability –Additional Overhead

9 Physical Resource Mapping for SubMAP Comparison –Latency : HARQ feedback delay DL:UL 5:3  1.6ms (TDM), 2.6ms (FDM) DL:UL 4:4  1.85ms (TDM), 1.85ms (FDM) DL:UL 4:4 (2 switching point)  1.85ms (TDM), 2.78ms (FDM) –Microsleep and MS complexity (FFT Buffer size: 2~3 (TDM), 7~8 (FDM)) –Granularity : 16.67% (TDM), 2.08~8.33% (FDM) of 1 subframe –Controllability : Hard to allocate localize RB for multiple MS (FDD) –Additional Overhead : FDD for indicating MAP allocation size TDMFDM Pros - Short feedback delay (ave. 1.6ms~1.85ms) - MS power saving with microsleep - Simple Separation of data & control region. - Low MS complexity - High frequency diversity - High granularity of the ratio between the control channel and the data channel - Relatively low unused subcarriers. Cons - Low granularity of the ratio between the control channel and the data channel - High Overhead with large unused subcarriers - Long Feedback Latency (ave. 1.85~2.8ms) - Large required buffer size for MS (7~8 symbols) - Cannot apply micro-sleep - Limited use of the frequency diversity

10 Physical Resource Mapping for SubMAP Scalable TDM –TDM with Flexible Size in Freq Domain Low feedback latency, microsleep with good granularity Relative large indication bits for MAP allocation region –CAU (Control Allocation Unit) : Basic allocation Unit Integer multiples of mini-RB (N= 3 (1%) ~ 16 (5.6 %)) Reduce the required bits to indicate the resource size with little loss of granularity gain

11 Physical Resource Mapping for SubMAP Hybrid TDM/FDM –TDM : main channel, a half (8.3%) or one symbol (16.67%) –FDM : supplementary channel, multiple RBs Decoding Delay is related to only DL SubMAP Only UL SubMAP shall be allocated to FDM RB –Partially Support Microsleep when no UL SubMAPs are to be transmitted (MS knows the existence of UL SubMAP in most cases)

12 Physical Resource Mapping for SubMAP Hybrid TDM/FDM –Allocation Step (Example) 1.TDM Allocation Steps ① Nc_dl = total number of required number of subcarriers for allocating SFCH and downlink SubMAPs. –Case A: if Nc_dl > 0.5 Ns (available subcarriers in a symbol), then one symbol is used. –Case B: otherwise just a half of a symbol is used ② Fill the allocated symbol with the SFCH and the downlink SubMAPs in TDM region. ③ If the unused subcarriers exist in that symbol, fill the remaining region with the uplink SubMAPs. 2.FDM Allocation Steps ① After TDM mapping, if you have another uplink SubMAPs not being allocated, choose Resource Blocks (FDM region) to allocate the remaining uplink SubMAPs. ② To achieve diversity gain, more than 2 ~4 RBs with the some amount of separation in the frequency band should be selected. It is preferable to choose two edge-RBs of the band firstly.

13 Physical Resource Mapping for SubMAP Comparison Results TDMFDMScalable TDM Hybrid TDM/FDM Latency (Feedback Delay)GoodPoorGood MicrosleepPossibleImpossiblePossiblePartially Possible Size of Buffer ( FFT )2~3 symbol> 7 symbol2~3 symbol Frequency DiversityGoodLimitedGood TDM: Good FDM: Limited Flexible Resource UsagePoorGood Allocation unit/ % ratio w.r.t. one subframe 1 symbol/ 16.67% 1 RB/ 2.08% 1 CAU/ 0.34*N % (1.7% for N=5) 2~4 RB (5 symbols) / 3.4~6.8 % Resource Allocation for Data Burst No Limitation Limit to allocate Localized RB No Limitations Smaller Limits than FDM Overhead for indicating MAP size (Assuming 16%~25% of control overhead) 0~1 bit3~4 bits3~7 bits1~4 bits

14 Conclusion We proposed a logical control structure composed of –SFCH (Sub-Frame Control Header) –SubMAP headers –SubMAPs. (per-MS or MS Group) We proposed two options of new efficient resource allocation schemes ; –Scalable TDM –Hybrid TDM/FDM Refer to the text proposal in C80216m-08/149