1. Synchronous Ranging Structure (AWD-15.3.9.1.4.2) Document Number: IEEE C80216m-09/1493r1 Date Submitted: 2009-07-06 Source: Yih-Shen Chen, Pei-Kai Liao and Paul Cheng E-mail: yihshen.chen@mediatek.com, pk.liao@mediatek.comyihshen.chen@mediatek.compk.liao@mediatek.com MediaTek Inc. Yan-Xiu Zheng E-mail: zhengyangxiu@itri.org.twzhengyangxiu@itri.org.tw ITRI Venue: IEEE Session #62, San Francisco, USA Response to IEEE 802.16m-09/0028r1, “Call for Comments and Contributions on Project 802.16 Amendment Content” Category: AWD comments / Area: Chapter 15.3.9 (UL-CTRL) “Comments on AWD 15.3.9.1.4.2 Ranging channel for synchronized AMSs” Base Contribution: This is base contribution Purpose: For TGm members’ discussion and approval 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 Design Considerations for Synchronized Ranging Channel Design considerations: –RCP length: Same CP size as data channel’s CP –Time accuracy criterion EX: < ± (T b /32)/4 (about 0.7143 us) for IEEE 802.16 system –Large cell coverage –Low overhead and high spectral efficiency Synchronized ranging channel can be applied for –Macrocell: Periodic ranging –Femtocell: Initial ranging (IR), handover ranging (HOR) –Purposes of initial ranging »UL synchronization: Time/power/frequency adjustment »Contention-based access request for network entry –Due to limited coverage, UL synchronization can be skipped after DL synchronization is done Periodic ranging (PR)

3. 3 Proposed Structure for Synchronized Ranging Structure (1/3) Basic structure: 1-subband x 1 OFDMA symbol –Time-domain repetition can be applied for larger coverage 2 or 3 There are three PR opportunities in one subframe if 2 repetitions are applied There are two PR opportunities in one subframe if 3 repetitions are applied for larger coverage

4. 4 Proposed Structure for Synchronized Ranging Structure (2/3) In macrocell, three ranging opportunities are allocated in a subframe if repetition number is 2 Allocation of “1-subband x 1-subframe” every M superframes in a 10 MHz BW –No entry delay constraint in PR For a smaller macrocell, time-domain repetition won’t be necessary and the rest of subcarriers can be formed as data resource blocks, just like that in a femtocell

5. 5 Proposed Structure for Synchronized Ranging Structure (3/3) In femtocell, synchronized ranging channel is TDM with data channel –The ranging channel occupies 72 subcarriers x 1 OFDM symbol –The rest of subcarriers can be formed as five-symbol CRUs The allocation of synchronous IR channel appears every N superframes –N must meet the idle-> active delay requirement (i.e., 100ms) Advantages: –Enough time accuracy –No extra entry delay –Higher spectral efficiency Disadvantage: –There exists two kinds of data PRUs in one subframe

6. 6 Proposed Code Sequence ~ Circularly-Shifted Padded ZC (PZC) Code Code sequence –Number of ZC =71 –m denotes circular shift value for each cell 0, 10, 20, 30, 40, 50, 60 70 sequences with u=1,…,70 are allocated per cell –70*7=490 sequences –PAPR=6.1089

7. 7 Simulations Results ~ configuration Single user to six users performance is evaluated Only the best quality user is estimated based on non-coherent detection Padded ZC code provides enhanced performance when the number of user increases –Padded Zadoff-Chu code rejects interference from other users Channel Bandwidth10MHz Over-sampling Factor28/25 FFT Size1024 Cyclic prefix (CP) ratio1/8 Channel ConditionPB3, VA30 VA120, VA350 The Number of Antennas Tx:1, Rx:2 ModulationMPSK Number of Users1, 2, 3, 4, 5, 6 ReceiverDetection: non- coherent MLD Estimation: differential detection

8. 8 Simulations Results ~ Single-user case 8

9. 9 Simulations Results ~ Two-user case 9

10. 10 Simulations Results ~ Three-user case 10

11. 11 Simulations Results ~ Four-user case 11

12. 12 Simulations Results ~ Five-user case 12

13. 13 Simulations Results ~ Six-user case 13

14. 14 Mis-Detection Issues for Overlaying Macrocell/Femtocell Deployment Since the ranging code/structure is reused in both macrocell and femtocell, there might be a signal mis- detection problem Solution: –The allocations of ranging opportunities are separated in time domain

15. 15 Conclusion The proposed synchronous ranging structure can fulfill the requirement of timing accuracy –Better spectral efficiency The synchronous ranging structure can also be applied in femtocells as IR, HOR and PR Compared with ZC code, Padded ZC code can provide better timing estimation performance

16. Text Proposal (1/4) [Modify section 15.3.9.1.4.2 of AWD with the following text]

17. Text Proposal (2/4) Fig. YYY: The allocation of code symbol on time and frequency domain

18. 18 Text Proposal (3/4) [Add the following text into a new section (15.3.9.2.4.2) of AWD]

19. 19 Text Proposal (4/4) Fig. ZZZ: The allocation of code symbol on time and frequency domain