1. 802.16m Frame Structure: Uplink Subframe Aggregation IEEE 802.16 Presentation Submission Template (Rev. 9) Document Number: IEEE S802.16m-08/099 Date Submitted: 2008-01-22 Source: S. Shawn Tsai, Stefan Lindgren, Sten Sjoberg, Anders Lamm Ericsson ABE-mail:shawn.tsai@ericsson.com Venue: IEEE 802.16m-07/047 - Call for Contributions on Project 802.16m System Description Document. Base Contribution: IEEE C802.16m-08/099 Purpose: To propose uplink subframe aggregation in the new 802.16m. Frame Structure to address the improved cell coverage requirement and to increase effective uplink data rates seen at the cell edge 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. 802.16m Frame Structure: Uplink Subframe Aggregation

3. Introduction This contribution introduces a new logical concept into the 802.16m Frame Structure. The proposal gives new 802.16m MS an optional logical aggregation of consecutive UL subframes to carry one MAC PDU burst. This addresses the improved cell coverage requirement and increases effective uplink data rates at the cell edge.

4. The 802.16 UL problem Large imbalance in BS and MS Tx powers Transmission only a fraction of the time, equals a relatively low energy per burst Large MAC PDU overhead (10 bytes minimum OH per burst with ARQ, 22 bytes OH if CMAC is used) Fragmentation inefficient for low rate communication (due to high MAC OH)

5. Proposal Introduce the option of aggregating multiple UL subframes into one logical unit for modulation and decoding, where one UL MAC PDU may span over multiple frames such that enough symbol energies are accumulated for better coverage and larger payload can be accomodated for better efficiency.

6. Proposed Uplink Subframe Aggregation Example of a frame structure with aggregated uplink subframes (the same color/pattern represents one logical uplink data burst)

7. Gains by aggregation (example) 35:12, QPSK rate ½, 2 repetitions # of aggregated subframes (one subch) Total PHY payload bits MAC overheadMAC PDU payload PHY data rateEffective data rate 196801619.2 kbps3.2 kbps 21928011219.2 kbps11.2 kbps (3.5x) (5.4 dB) 32888020819.2 kbps13.86 kbps (4.3x) (6.3 dB) 43848030419.2 kbps15.2 kbps (4.75x) (6.8 dB)

8. Proposed SDD Text [Section] Frame Structure [Subsection] Uplink Subframe Aggregation Please see contribution C802.16m-08/099 for the actual text proposal.